BUTTERFLY VALVE

A butterfly valve for a conduit defining a passage for a flow of a fluid therethrough in a flow direction. The butterfly valve includes a shaft rotatably mounted to the conduit and defining a longitudinal axis along its length. The butterfly valve includes a valve body coupled to the shaft, such that the valve body is rotatable along with the shaft about the longitudinal axis between a closed position and a fully open position. The valve body includes a first major surface, a second major surface opposite to the first major surface, a perimeter surface, a central plane, a first lobe, a second lobe, and a third lobe.

CROSS-REFERENCE TO RELATED APPLICATIONS

This specification is based upon and claims the benefit of priority from United Kingdom patent application GB 2311720.3 filed on Jul. 31, 2023, the entire contents of which is incorporated herein by reference

BACKGROUND

Technical Field

The present disclosure generally relates to a butterfly valve and a method of manufacturing a butterfly valve.

Description of the Related Art

In gas turbines, one or more bleed valves are associated with a compressor (intermediate pressure compressor or low pressure compressor). Bleed air from the one or more bleed valves may be vented into a bypass duct of the gas turbine engine. The bleed valve may be opened when the gas turbine is operated at or close to idle.

For bleeding the compressor, bi-static valves are commonly used as bleed valves as they permit a level of stepped modulation for handling the compressor. However, the stepped modulation by the bi-static valves may not allow maximum thermal efficiency of the compressor at a non-dimensional speed. Operation of the bi-static valves may cause discrete changes in a working line (and operating point) of the compressor as the bi-static valves have only two operating states (i.e., fully open or fully closed). During use of the bi-static valves, a leak may also develop over time.

Another type of valve that is commonly used for bleeding the compressor is a sliding sleeve valve. The sliding sleeve valve is particularly helpful to control boosted stages of the compressor. The sliding sleeve valve provides ample area, but because a total movement of the sleeve is small, fine actuation control may be difficult. Thus, the sliding sleeve valve may be difficult to control as per application requirements.

Therefore, there is a need for an improved valve (i.e., a butterfly valve) for bleeding the compressor in the gas turbine. Conventional designs of the bleed valves may not provide optimal thermal efficiency of the compressor, especially during transient operation of the gas turbine. Moreover, control accuracy of the conventional designs of the bleed valves may be low. In some cases, due to higher torque loading, a size of valve actuator cannot be reduced and that in turn increases an overall cost of manufacturing the valves and the valve actuators.

SUMMARY

According to a first aspect there is provided a butterfly valve for a conduit defining a passage for a flow of a fluid therethrough in a flow direction. The butterfly valve includes a shaft rotatably mounted to the conduit and defining a longitudinal axis along its length, such that the shaft is rotatable about the longitudinal axis. The butterfly valve further includes a valve body coupled to the shaft, such that the valve body is rotatable along with the shaft about the longitudinal axis between a closed position and a fully open position. The valve body defines a transverse axis perpendicular to the longitudinal axis. In the closed position, the valve body engages the conduit to close the passage. In the fully open position, the valve body opens the passage to allow the flow of the fluid. The valve body includes a first major surface facing the flow of the fluid when the valve body is in the closed position. The first major surface includes a first central line extending along the length of the shaft parallel to the longitudinal axis. The valve body further includes a second major surface opposite to the first major surface. The second major surface includes a second central line extending along the length of the shaft parallel to the longitudinal axis. The valve body further includes a perimeter surface that is arcuate and extends between the first major surface and the second major surface. The perimeter surface is configured to engage with the conduit in the closed position of the valve body. The perimeter surface includes a leading portion that is spaced apart from each of the first central line and the second central line, and a trailing portion that is diametrically opposite to the leading portion. In the fully open position, the leading portion is a most upstream edge of the perimeter surface with respect to the flow direction and the trailing portion is a most downstream edge of the perimeter surface with respect to the flow direction. The transverse axis of the valve body extends between the leading portion and the trailing portion. The valve body further includes a central plane disposed between the first major surface and the second major surface. The central plane contains the longitudinal axis, a central point of the leading portion, and a central point of the trailing portion. The perimeter surface defines a diameter of the valve body in the central plane. The valve body further defines a first direction normal to the central plane and extending towards the first major surface. The valve body further defines a second direction opposite to the first direction.

The valve body further includes a first lobe partially forming the first major surface and extending at least partially from the leading portion towards the first central line along the transverse axis. The first lobe further extends at least partially along the longitudinal axis. The first lobe includes a first peak edge that is disposed proximal to the leading portion, such that the first lobe ascends from the leading portion to the first peak edge at least along the first direction and descends from the first peak edge towards the first central line. The valve body further includes a second lobe partially forming the second major surface and extending at least partially from the leading portion towards the second central line along the transverse axis. The second lobe further extends at least partially along the longitudinal axis. The second lobe includes a second peak edge that is disposed proximal to the leading portion, such that the second lobe ascends from the leading portion to the second peak edge at least along the second direction and descends from the second peak edge towards the second central line. The valve body further includes a third lobe spaced apart from each of the first lobe and the second lobe and partially forming the second major surface. The third lobe extends from the trailing portion towards the second central line along the transverse axis. The third lobe further extends at least partially along the longitudinal axis. The third lobe includes a third peak edge that is disposed proximal to the trailing portion, such that the third lobe ascends from the trailing portion to the third peak edge at least along the second direction and descends from the third peak edge towards the second central line. The first lobe and the second lobe are disposed on opposing sides of the central plane. The second lobe and the third lobe are disposed on the same side of the central plane. Each of the first peak edge, the second peak edge, and the third peak edge is rounded.

The inclusion of the first lobe, the second lobe, and the third lobe may cause reduced torque loading on the butterfly valve of the present disclosure as compared to that of conventional butterfly valves. The first lobe, the second lobe, and the third lobe may provide the butterfly valve with an optimized geometry that results in the reduced torque loading along with minimal flow capacity reduction across an operating range of the butterfly valve of the present disclosure. This may provide an improved performance of the butterfly valve when installed for bleeding purposes in an apparatus (e.g., a gas turbine engine). Further, the inclusion of the first lobe, the second lobe, and the third lobe does not restrict any movement of the butterfly valve of the present disclosure, thereby making it possible to be easily controlled by a valve actuator.

While the reduced torque loading is achieved with appropriate consideration for flow discharge requirements across the operating range of the butterfly valve, a size of the valve actuator may also be relatively reduced. Further, the inclusion of the first lobe, the second lobe, and the third lobe may lead to usage of less material for the manufacturing of the butterfly valve of the present disclosure as compared to the conventional butterfly valves. This may save a cost of manufacturing the butterfly valve of the present disclosure and the valve actuator.

In some embodiments, each of the first peak edge, the second peak edge, and the third peak edge extends parallel to the longitudinal axis. This extension of the first peak edge, the second peak edge, and the third peak edge parallel to the longitudinal axis may result in the optimized geometry of the butterfly valve.

In some embodiments, the first lobe further includes a planar surface ascending from the leading portion to the first peak edge and a concave surface descending from the first peak edge towards the first central line. Such shape and geometry of the first lobe may enhance the reduction of torque loading on the butterfly valve.

In some embodiments, the planar surface is inclined to the central plane by an inclination angle of from 40 degrees to 50 degrees. This range of the inclination angle of the planar surface with the central plane may provide the butterfly valve with the optimized geometry for torque reduction and maintaining the appropriate flow discharge across the butterfly valve.

In some embodiments, a first peak distance between the leading portion and the first peak edge is from 8% to 10% of the diameter of the valve body. This may result in the optimized geometry of the butterfly valve.

In some embodiments, a second peak distance between the leading portion and the second peak edge is equal to a third peak distance between the trailing portion and the third peak edge. Each of the second peak distance and the third peak distance is from 14% to 16% of the diameter of the valve body. This may improve flow performance, for example, a flow coefficient, of the fluid across the butterfly valve.

In some embodiments, a first peak height between the first peak edge and the central plane is from 9% to 11% of the diameter of the valve body. A second peak height between the second peak edge and the central plane is from 6% to 8% of the diameter of the valve body. A third peak height between the third peak edge and the central plane is from 5% to 7% of the diameter of the valve body. All such dimensions related to the first lobe, the second lobe, and the third lobe may provide the butterfly valve with the optimized geometry with corresponding benefits.

In some embodiments, a first peak length of the first peak edge parallel to the first central line is from 50% to 55% of the diameter of the valve body. This may result in the optimized geometry of the butterfly valve.

In some embodiments, a second peak length of the second peak edge parallel to the second central line is equal to a third peak length of the third peak edge parallel to the second central line. This may mitigate against flow separation in the conduit while the fluid passes therethrough in the fully open position of the valve body.

In some embodiments, the first peak edge is closer to the leading portion than the second peak edge with respect to the transverse axis. This may improve flow performance of the fluid across the butterfly valve.

In some embodiments, the second lobe includes a second convex surface extending from the corresponding leading portion towards the second central line along the transverse axis, such that the second convex surface includes the second peak edge. The third lobe includes a third convex surface extending from the corresponding trailing portion towards the second central line along the transverse axis, such that the third convex surface includes the third peak edge. The second convex surface and the third convex surface may facilitate flow continuity of the fluid across the second major surface of the butterfly valve.

In some embodiments, the first lobe is continuous with the perimeter surface. This may mitigate against flow separation in the vicinity of the first lobe.

In some embodiments, the first major surface includes a planar surface portion extending from the trailing portion to the first lobe and including the first central line. The planar surface portion is adjacent to the perimeter surface. This may result in the optimized geometry of the butterfly valve.

In some embodiments, the second major surface includes a central concave surface portion extending between the second lobe and the third lobe. The central concave surface portion includes the second central line. This may mitigate against flow separation in the conduit while the fluid passes therethrough in the fully open position of the valve body.

In some embodiments, the second major surface portion further includes a first planar surface portion extending from the perimeter surface at least along the longitudinal axis. The second major surface further includes a second planar surface portion disposed opposite to the first planar surface portion and extending from the perimeter surface at least along the longitudinal axis. The second major surface further includes a first intermediate surface portion rising from the first planar surface portion at least along the second direction to each of the second lobe, the third lobe, and the central concave surface portion. The first intermediate surface portion further extends at least partially along the transverse axis. The second major surface further includes a second intermediate surface portion disposed opposite to the first intermediate surface portion and rising from the second planar surface portion at least along the second direction to each of the second lobe, the third lobe, and the central concave surface portion. The second intermediate surface portion further extends at least partially along the transverse axis. Each of the second lobe, the third lobe, and the central concave surface portion is at least partially separated from the perimeter surface by the first planar surface portion and the second planar surface portion. The first planar surface portion, the second planar surface portion, the first intermediate surface portion, and the second intermediate surface portion may provide the butterfly valve with the optimized geometry for reduced torque loading as well as maximum flow discharge across the butterfly valve.

In some embodiments, each of the first intermediate surface portion and the second intermediate surface portion is at least partially concave. This may facilitate flow continuity of the fluid across the second major surface of the butterfly valve.

In some embodiments, the central concave surface portion is adjacent to the perimeter surface. This may result in the optimized geometry of the butterfly valve.

In some embodiments, each of the second lobe and the third lobe is at least partially spaced apart from the perimeter surface with respect to the longitudinal axis. This may provide the butterfly valve with the optimized geometry for a desirable amount of flow discharge across the butterfly valve.

In some embodiments, each of the second lobe and the third lobe is continuous with the perimeter surface. This may mitigate against flow separation in the conduit while the fluid passes therethrough in the fully open position of the valve body.

In some embodiments, the shaft includes a first shaft portion and a second shaft portion spaced apart from the first shaft portion with respect to the longitudinal axis. The first shaft portion and the second shaft portion are coupled to the valve body on opposing sides, such that each of the first central line and the second central line extends between the first shaft portion and the second shaft portion. The shaft may be driven by a drive mechanism or a valve actuator in order to open and close the butterfly valve within the conduit.

In some embodiments, the valve body is rotated by 90 degrees about the longitudinal axis relative to the closed position to open the passage. The valve body defines a valve angle that is equal to an angle of rotation of the valve body about the longitudinal axis relative to the closed position, such that the valve angle is equal to 0 degree at the closed position. The butterfly valve has a torque coefficient that is equal to a ratio of a torque applied on the butterfly valve to rotate the butterfly valve to a product of the cube of the diameter of the valve body and a pressure drop across the butterfly valve within the conduit. The butterfly valve and a comparative butterfly valve have the same construction and diameter except that first and second major surfaces of the comparative butterfly valve are planar without any lobes. For similar flow conditions within the conduit, the torque coefficient of each of the butterfly valve and the comparative butterfly valve varies with the valve angle and has a corresponding peak value. The peak value of the torque coefficient of the butterfly valve is less than the peak value of the torque coefficient of the comparative butterfly valve by at least 30%. As the peak value of the torque coefficient of the butterfly valve is less than the peak value of the torque coefficient of the comparative butterfly valve by at least 30%, it is evident that the butterfly valve of the present disclosure provides the optimized geometry for reduced torque loading as well as minimal flow capacity reduction across the operating range of the butterfly valve. This may improve an overall performance of the butterfly valve and the apparatus (for example, a gas turbine engine) in which the butterfly valve is installed.

In some embodiments, the first lobe, the second lobe, and the third lobe together reduce the peak value of the torque coefficient of the butterfly valve by at least 50% relative to the peak value of the torque coefficient of the comparative butterfly valve. Thus, the butterfly valve of the present disclosure is aerodynamically optimized for a desirable torque reduction relative to that of the comparative butterfly valve.

The butterfly valve has a flow coefficient that is equal to a ratio of a mass flow rate of the fluid flowing through the conduit to a product of an area of the butterfly valve in the central plane and a square root of twice a product of a density of the fluid and the pressure drop across the butterfly valve. The flow coefficient of each of the butterfly valve and the comparative butterfly valve varies with the valve angle. For similar flow conditions within the conduit and for any value of the valve angle, a maximum difference between the flow coefficient of the butterfly valve and the flow coefficient of the comparative butterfly valve is at most 10%. Specifically, the flow coefficient of the butterfly valve is less than the flow coefficient of the comparative butterfly valve by at most 10%. As the maximum difference between the flow coefficient of the butterfly valve of the present disclosure and the flow coefficient of the comparative butterfly valve is at most 10%, it is evident that there is minimal flow capacity reduction across the operating range of the butterfly valve of the present disclosure. Hence, considering the comparison of the peak value of the torque coefficient of the butterfly valve with the peak value of the torque coefficient of the comparative butterfly valve, and the comparison of the flow coefficient of the butterfly valve with the flow coefficient of the comparative butterfly valve, it can be stated that the butterfly valve of the present disclosure may provide a desirable torque loading as well as an achievable flow capacity across the operating range of the butterfly valve.

According to a second aspect there is provided a gas turbine. The gas turbine includes a compressor, a bleed conduit disposed in fluid communication with the compressor, and the butterfly valve of the first aspect. The butterfly valve is disposed in the bleed conduit. The optimized geometry of the butterfly valve of the present disclosure may result in improved thermal efficiency of the compressor in the gas turbine, relative to a compressor comprising at least one bi-static bleed valve. This is because as a bi-static bleed valve only has two operating states (for example, fully open or fully closed), operation of the at least one bi-static bleed valve causes discrete changes in a working line (and operating point) of the compressor. In contrast, the optimised geometry of the butterfly valve permits continuous modulation of the degree of bleed flow, leading to continuous variation in compressor working line, allowing selection of a compressor working line that corresponds to a higher compressor efficiency. In this way, an overall efficiency of the gas turbine may be increased.

According to a third aspect there is provided a method of manufacturing the butterfly valve of the first aspect. The method includes providing a base disc model having a diameter equal to the valve body of the butterfly valve. The base disc model includes a first base major surface, a second base major surface opposite to the first base major surface, and a base perimeter surface extending between the first base major surface and the second base major surface. Each of the first base major surface and the second base major surface is planar. The method further includes providing a plurality of surface splines on the base disc model to modify the first base major surface and the second base major surface in order obtain a plurality of parametrized baseline geometries corresponding to the plurality of surface splines. A surface spline can be understood as a mathematical representation for which it is easy to build an interface that will allow a user to design and control the shape of complex curves and surfaces. The method further includes performing, by a simulator software, simulation on the plurality of parametrized baseline geometries based on computational fluid dynamics (CFD) in order to obtain pressure and velocity distributions across various points on each of the plurality of parametrized baseline geometries. The method further includes exporting, by a solver, simulation data including a mass flow rate of the fluid across each of the plurality of parametrized baseline geometries and a torque applied on each of the plurality of parametrized baseline geometries to form export data. The method further includes selecting at least one parameterized base geometry from the plurality of parametrized baseline geometries based on the export data. The method further includes creating, by a solver, a surrogate Gaussian process regression model based on the export data and geometrical parameters of each of the at least one parametrized baseline geometry. A surrogate model may refer to a mathematical model that seeks to predict, such as by interpolating or extrapolating a response, or output, based on output values previously acquired from empirical observation and/or mathematical calculations, including calculations using an existing full-physics model. Such surrogate model is generated by using Gaussian process regression model.

The method further includes minimizing, by the surrogate Gaussian process regression model, an objective function in order to generate geometrical parameters of a butterfly valve model corresponding to the butterfly valve. The method further includes verifying, by the simulator software, the geometrical parameters of the butterfly valve based on the mass flow rate across the butterfly valve model and the torque applied on butterfly valve model. The method further includes manufacturing the butterfly valve based on the butterfly valve model.

The surrogate Gaussian process regression model may improve an efficiency of the manufacturing process of the butterfly valve of the present disclosure. The surrogate Gaussian process regression model may allow a reduction in the overall computation load, thereby increasing the efficiency of the manufacturing process of the butterfly valve.

The method of the third aspect uses different sequential steps to achieve the final and optimized geometry of the butterfly valve disclosed in the first aspect. The steps of the method can be varied based on different application attributes.

DETAILED DESCRIPTION

Note that the terms “low pressure turbine” and “low pressure compressor” as used herein may be taken to mean the lowest pressure turbine stages and lowest pressure compressor stages (i.e. not including the fan23) respectively and/or the turbine and compressor stages that are connected together by the interconnecting shaft26with the lowest rotational speed in the engine (i.e. not including the gearbox output shaft that drives the fan23). In some literature, the “low pressure turbine19” and “low pressure compressor14” referred to herein may alternatively be known as the “intermediate pressure turbine19” and “intermediate pressure compressor14”, respectively. Where such alternative nomenclature is used, the fan23may be referred to as a first, or lowest pressure, compression stage. The low pressure compressor14may be interchangeably referred to herein as the “intermediate pressure compressor14”.

The gas turbine engine10further includes a bleed conduit32disposed in fluid communication with the compressor (e.g., the intermediate pressure compressor14). The bleed conduit32allows selective removal of air downstream of the intermediate pressure compressor14, thereby allowing a reduction of pressure ratio across the intermediate pressure compressor14. In the illustrated embodiment ofFIG.1, the bleed conduit32exits the air into the bypass duct22. The bleed conduit32can be interchangeably referred to herein as “a conduit32”. The conduit32defines a passage34for a flow of a fluid therethrough in a flow direction F1. In the gas turbine engine10, the fluid is air. In some other examples, the fluid may be some other gas, or a liquid. The gas turbine engine10further includes a butterfly valve50for the conduit32. The butterfly valve50is disposed in the bleed conduit32. The butterfly valve50is configured to handle and control the air flow (bleed flow) through the bleed conduit32.

FIGS.2A and2Bare sectional front views of the conduit32associated with the intermediate compressor14of the gas turbine engine10ofFIG.1with the butterfly valve50disposed in the conduit32in different positions, according to an embodiment of the present disclosure.FIG.2Cis a sectional side view of the conduit32with the butterfly valve50in the position ofFIG.2B, according to an embodiment of the present disclosure. Referring toFIGS.2A to2C, the butterfly valve50includes a shaft52rotatably mounted to the conduit32. The shaft52defines a longitudinal axis LA along its length, such that the shaft52is rotatable about the longitudinal axis LA. The butterfly valve50further includes a valve body100coupled to the shaft52, such that the valve body100is rotatable along with the shaft52about the longitudinal axis LA between a closed position P1and a fully open position P2. In the illustrated embodiment ofFIG.2A, the valve body100is shown in the closed position P1. In the illustrated embodiment ofFIG.2B, the valve body100is shown in the fully open position P2. The valve body100is also shown in the fully open position P2inFIG.2C.

In some embodiments, the shaft52includes a first shaft portion54and a second shaft portion56spaced apart from the first shaft portion54with respect to the longitudinal axis LA. The first shaft portion54and the second shaft portion56are coupled to the valve body100on opposing sides. The valve body100defines a transverse axis TA perpendicular to the longitudinal axis LA. In the closed position P1the valve body100engages the conduit32to close the passage34. In the fully open position P2, the valve body100opens the passage34to allow the flow of the fluid.

The valve body100is rotated by 90 degrees about the longitudinal axis LA relative to the closed position P1to open the passage34. A valve actuator (not shown) rotates the valve body100along with the shaft52based on flow requirements. The valve actuator may be a motor drive. The valve body100defines a valve angle β (illustrated inFIG.7A) that is equal to an angle of rotation of the valve body100about the longitudinal axis LA relative to the closed position P1, such that the valve angle β is equal to 0 degree at the closed position P1. The valve angle β is equal to 90 degrees at the fully open position P2.

FIG.3Ais a perspective top view of the butterfly valve50ofFIG.2A, according to an embodiment of the present disclosure. The butterfly valve50defines mutually orthogonal x, y, and z-axes. The x and y-axes are in-plane axes of the butterfly valve50, while the z-axis is disposed along a thickness of the butterfly valve50. In other words, x and y-axes are along a plane of the butterfly valve50defining a xy-plane, and the z-axis is perpendicular to the xy-plane of the butterfly valve50. The longitudinal axis LA extends along the y-axis. The transverse axis TA extends along the x-axis.

FIG.3Bis another perspective top view of the butterfly valve50, according to an embodiment of the present disclosure.FIG.3Cis a perspective bottom view of the butterfly valve50, according to an embodiment of the present disclosure.FIG.3Dis a perspective sectional view of the butterfly valve50ofFIG.3C, taken along a line A-A′, according to an embodiment of the present disclosure.FIG.4Ais a top view of the butterfly valve50, according to an embodiment of the present disclosure.FIG.4Bis a bottom view of the butterfly valve50, according to an embodiment of the present disclosure.FIG.5Ais a side view of the butterfly valve50, as viewed from a first side A1, according to an embodiment of the present disclosure.FIG.5Bis a side view of the butterfly valve50, as viewed from a second side A2opposite to the first side A1, according to an embodiment of the present disclosure.FIG.6Ais a front view of the butterfly valve50ofFIG.3A, according to an embodiment of the present disclosure.FIG.6Bis a rear view of the butterfly valve50ofFIG.3A, according to an embodiment of the present disclosure.

Referring toFIGS.3A to6B, the valve body100includes a first major surface102(shown inFIGS.3C and4B) facing the flow of the fluid when the valve body100is in the closed position P1(shown inFIG.2A). The first major surface102includes a first central line104extending along the length of the shaft52parallel to the longitudinal axis LA. The valve body100further includes a second major surface106opposite to the first major surface102. The second major surface106includes a second central line108extending along the length of the shaft52parallel to the longitudinal axis LA. Therefore, the first central line104is parallel to the second central line108. Each of the first central line104and the second central line108extends between the first shaft portion54and the second shaft portion56.

The valve body100further includes a perimeter surface110that is arcuate and extends between the first major surface102and the second major surface106. The perimeter surface110is configured to engage with the conduit32(shown inFIG.2A) in the closed position P1of the valve body100. The perimeter surface110includes a leading portion112that is spaced apart from each of the first central line104and the second central line108. The perimeter surface110further includes a trailing portion114that is diametrically opposite to the leading portion112. In the fully open position P2(shown inFIGS.2B and2C), the leading portion112is a most upstream edge of the perimeter surface110with respect to the flow direction F1and the trailing portion114is a most downstream edge of the perimeter surface110with respect to the flow direction F1. The transverse axis TA of the valve body100extends between the leading portion112and the trailing portion114.

The valve body100further includes a central plane CP (best shown inFIG.3D) disposed between the first major surface102and the second major surface106. The central plane CP contains the longitudinal axis LA, a central point113(shown inFIGS.5A and5B) of the leading portion112, and a central point115(shown inFIGS.5A and5B) of the trailing portion114. The central plane CP lies in the xy-plane.

The perimeter surface110defines a diameter D (shown inFIGS.4A and5A) of the valve body100in the central plane CP. The valve body100further defines a first direction D1normal to the central plane CP and extending towards the first major surface102. The valve body100further defines a second direction D2opposite to the first direction D2. Each of the first direction D1and the second direction D2extends along the z-axis.

The valve body100further includes a first lobe116partially forming the first major surface102. The first lobe116extends at least partially from the leading portion112towards the first central line104along the transverse axis TA. The first lobe116further extends at least partially along the longitudinal axis LA.

The first lobe116includes a first peak edge118that is disposed proximal to the leading portion112. The first lobe116ascends from the leading portion112to the first peak edge118at least along the first direction D1and descends from the first peak edge118towards the first central line104. The first lobe116further includes a planar surface120ascending from the leading portion112to the first peak edge118. The first lobe116further includes a concave surface122descending from the first peak edge118towards the first central line104.

In some embodiments, the planar surface120is inclined to the central plane CP by an inclination angle α (shown inFIG.5A) of from 40 degrees to 50 degrees. In some embodiments, the inclination angle α is 45 degrees. In some embodiments, a first peak distance S1(shown inFIG.5A) between the leading portion112and the first peak edge118is from 8% to 10% of the diameter D of the valve body100. In some embodiments, the first peak distance S1is 9% of the diameter D of the valve body100. In some embodiments, the first peak distance S1may be from 5% to 15% of the diameter D of the valve body100.

In some embodiments, a first peak height H1(shown inFIG.5B) between the first peak edge118and the central plane CP is from 9% to 11% of the diameter D of the valve body100. In some embodiments, the first peak height H1is 10% of the diameter D of the valve body100. In some embodiments, the first peak height H1may be from 4.5% to 16.5% of the diameter D of the valve body100. In some embodiments, a first peak length L1(shown inFIGS.6A and6B) of the first peak edge118parallel to the first central line104is from 50% to 55% of the diameter D of the valve body100. In some embodiments, the first peak length L1is 52.5% of the diameter D of the valve body100. In some embodiments, the first peak length L1may be from 36% to 66% of the diameter D of the valve body100.

The first major surface102further includes a planar surface portion124(shown inFIGS.5A and5B) extending from the trailing portion114to the first lobe116. The planar surface portion124may include the first central line104. The planar surface portion124is adjacent to the perimeter surface110. Further, in the illustrated embodiment ofFIGS.3A to6B, the first lobe116is continuous with the perimeter surface110.

The valve body100further includes a second lobe126partially forming the second major surface106of the valve body100. The second lobe126extends at least partially from the leading portion112towards the second central line108along the transverse axis TA. The second lobe126further extends at least partially along the longitudinal axis LA. The first lobe116and the second lobe126are disposed on opposing sides of the central plane CP.

The second lobe126includes a second peak edge128that is disposed proximal to the leading portion112. The second lobe126ascends from the leading portion112to the second peak edge128at least along the second direction D2and descends from the second peak edge128towards the second central line108. In some embodiments, a second peak height H2(shown inFIG.5B) between the second peak edge128and the central plane CP is from 6% to 8% of the diameter D of the valve body100. In some embodiments, the second peak height H2is 7% of the diameter D of the valve body100. In some embodiments, the second peak height H2may be from 4.5% to 11% of the diameter D of the valve body100. In some embodiments, the first peak edge118is closer to the leading portion112than the second peak edge128with respect to the transverse axis TA.

The second lobe126further includes a second convex surface130extending from the corresponding leading portion112towards the second central line108along the transverse axis TA, such that the second convex surface130includes the second peak edge128.

The valve body100further includes a third lobe132spaced apart from each of the first lobe116and the second lobe126. The third lobe132partially forms the second major surface106of the valve body100. The third lobe extends from the trailing portion114towards the second central line108along the transverse axis TA. The third lobe132further extends at least partially along the longitudinal axis LA. The second lobe126and the third lobe132are disposed on the same side of the central plane CP. Further, in the illustrated embodiment ofFIGS.3A to6B, each of the second lobe126and the third lobe132is continuous with the perimeter surface110.

The third lobe132includes a third peak edge134that is disposed proximal to the trailing portion114. The third lobe132ascends from the trailing portion114to the third peak edge134at least along the second direction D2and descends from the third peak edge134towards the second central line108. Each of the first peak edge118, the second peak edge128, and the third peak edge134is rounded. In some embodiments, each of the first peak edge118, the second peak edge128, and the third peak edge134extends parallel to the longitudinal axis LA.

In some embodiment, a third peak height H3(shown inFIG.5B) between the third peak edge134and the central plane CP is from 5% to 7% of the diameter D of the valve body100. In some embodiments, the third peak height H3is 6% of the diameter D of the valve body100. In some embodiments, the peak third height H3may be from 1.8% to 11% of the diameter D of the valve body100. In some embodiments, a second peak distance S2between the leading portion112and the second peak edge128is equal to a third peak distance S3(shown inFIG.5A) between the trailing portion114and the third peak edge134. In some embodiments, each of the second peak distance S2and the third peak distance S3is from 14% to 16% of the diameter D of the valve body100. In some embodiments, each of the second peak distance S2and the third peak distance S3is 15% of the diameter D of the valve body100. In some embodiments, each of the second peak distance S2and the third peak distance S3may be from 9% to 22% of the diameter D of the valve body100.

In some embodiments, a second peak length L2(shown inFIG.6A) of the second peak edge128parallel to the second central line108is equal to a third peak length L3(shown inFIG.6B) of the third peak edge134parallel to the second central line108. Each of the second peak length L2and the third peak length L3is from 40% to 70% of the diameter D of the valve body100. In some embodiments, each of the second peak length L2and the third peak length L3is about 55% of the diameter D of the valve body100. In some embodiments, each of the second peak length L2and the third peak length L3is from 27% to 88% of the diameter D of the valve body100.

In some embodiments, the first peak distance S1is from 15% to 20% of the first peak length L1. In some embodiments, the first peak distance S1is about 17% of the first peak length L1. In some embodiments, the first peak distance S1is from 13% to 22% of the first peak length L1. In some embodiments, the second peak distance S2is from 18% to 24% of the second peak length L2. In some embodiments, the second peak distance S2is about 21% of the second peak length L2. In some embodiments, the second peak distance S2is from 16% to 26% of the second peak length L2. Similarly, in some embodiments, the third peak distance S3is from 18% to 24% of the third peak length L3. In some embodiments, the third peak distance S3is about 21% of the third peak length L3. In some embodiments, the third peak distance S3is from 16% to 26% of the third peak length L3.

Further, it should be noted that a value of the first peak length L1decreases with a value of the first peak distance S1and vice versa. In other words, the value of the first peak length L1decreases as the first peak edge118moves closer to the leading portion112, and the value of the first peak length L1increases as the first peak edge118moves closer to the first central line104. Similarly, a value of the second peak length L2decreases with a value of the second peak distance S2and vice versa. In other words, the value of the second peak length L2decreases as the second peak edge128moves closer to the leading portion112, and the value of the second peak length L2increases as the second peak edge128moves closer to the second central line108. Similarly, a value of the third peak length L3decreases with a value of the third peak distance S3and vice versa. In other words, the value of the third peak length L3decreases as the third peak edge134moves closer to the trailing portion114, and the value of the third peak length L3increases as the third peak edge134moves closer to the second central line108.

In some embodiments, the third lobe132includes a third convex surface136extending from the corresponding trailing portion114towards the second central line108along the transverse axis TA, such that the third convex surface136includes the third peak edge134.

The shapes and positions of the first lobe116, the second lobe126, and the third lobe132, as described above, may vary based on application requirements. In some alternative examples, the first lobe116may have a curved portion (not shown) instead of the planar surface120. Further, in some examples, the first lobe116may be convex instead of including the concave surface122. Moreover, in some examples, each of the second lobe126and the third lobe132may be partially concave instead of being substantially convex.

In some embodiments, the second major surface106further includes a central concave surface portion138extending between the second lobe126and the third lobe132. The central concave surface portion138includes the second central line108. In the illustrated embodiment ofFIGS.3A to6B, the central concave surface portion138is adjacent to the perimeter surface110.

Torque and flow discharge values associated with the butterfly valve50were determined using a test. For this determination, the butterfly valve50was placed in a test rig (not shown). The test rig included an upstream section having the butterfly valve50and a downstream section having a vacuum tank. The test rig also included a plurality of actively controlled valves between the vacuum tank and the butterfly valve50. The plurality of actively controlled valves provided a constant set pressure differential between the upstream section and the downstream section. The test rig was operated by drawing atmospheric air through the upstream section and then through the plurality of actively controlled valves into the vacuum tank. The plurality of actively controlled valves were adjusted based on flow conditions and predetermined test profile to maintain the set pressure differential. Similar testing method was used to determine torque and flow discharge values associated with a comparative valve.

The butterfly valve50has a torque coefficient CT1that is equal to a ratio of a torque T applied on the butterfly valve50to rotate the butterfly valve50to a product of the cube of the diameter D of the valve body100and a pressure drop Δp across the butterfly valve50within the conduit32. In other words, the torque coefficient CT1of the butterfly valve50is calculated according to Equation 1 provided below:

CT⁢1=(T)/(D3*Δ⁢p)(Equation⁢1)where, CT1is the torque coefficient of the butterfly valve50;T is torque applied of the butterfly valve50to rotate the butterfly valve50;D is the diameter of the valve body100; andΔp is the pressure drop across the butterfly valve50within the conduit32.

FIG.7Ais a graph58illustrating torque coefficient versus valve angle β for each of the butterfly valve50and the comparative butterfly valve (not shown), according to an embodiment of the present disclosure. The valve angle β is shown in the abscissa in degrees and the torque coefficient is shown in the ordinate. The valve angle β is equal to an angle of rotation of the valve body100about the longitudinal axis LA relative to the closed position P1, such that the valve angle β is equal to 0 degree at the closed position P1. The valve angle β is equal to 90 degrees at the fully open position P2. The butterfly valve50and the comparative butterfly valve have the same construction and diameter (i.e., the diameter D) except that first and second major surfaces of the comparative butterfly valve are planar without any lobes. Therefore, the graph58illustrates the torque coefficient CT1versus valve angle β for the butterfly valve50, and a torque coefficient CTversus valve angle β for the comparative butterfly valve.

For similar flow conditions within the conduit32, the torque coefficient CT1of the butterfly valve50varies with the valve angle β and has a peak value PV1, and the torque coefficient CTof the comparative butterfly valve varies with the valve angle β and has a peak value PV. In other words, for similar flow conditions within the conduit32, the torque coefficient of each of the butterfly valve50and the comparative butterfly valve varies with the valve angle β and has a corresponding peak value (i.e., PV1and PV). The peak value PV1of the torque coefficient CT1of the butterfly valve50is less than the peak value PV of the torque coefficient CTof the comparative butterfly valve by at least 30%. In the illustrated embodiment ofFIG.7A, the peak value PV1of the torque coefficient CT1of the butterfly valve50is less than the peak value PV of the torque coefficient CTof the comparative butterfly valve by at least 50%.

Referring toFIGS.1to7A, the first lobe116, the second lobe126, and the third lobe132together reduce the peak value PV1of the torque coefficient CT1of the butterfly valve50by at least 50% relative to the peak value PV of the torque coefficient CTof the comparative butterfly valve. The inclusion of the first lobe116, the second lobe126, and the third lobe132may cause reduced torque loading on the butterfly valve50as compared to that of conventional butterfly valves or the comparative butterfly valve. Thus, the butterfly valve50of the present disclosure is aerodynamically optimized for a desirable torque reduction relative to that of the comparative butterfly valve. This may improve an overall performance of the butterfly valve50and the gas turbine engine10in which the butterfly valve50is being installed.

The butterfly valve50has a flow coefficient CF1that is equal to a ratio of a mass flow rate “m” of the fluid flowing through the conduit32to a product of an area A of the butterfly valve50in the central plane CP and a square root of twice a product of a density p of the fluid and the pressure drop Δp across the butterfly valve50. In other words, the flow coefficient CF1of the butterfly valve50is calculated according to Equation 2 provided below:

CF⁢1=(m)/(A*(2*ρ*Δ⁢p)1/2)(Equation⁢2)where, CF1is the flow coefficient of the butterfly valve50;“m” is the mass flow rate of the fluid flowing through the conduit32;A is area of the butterfly valve50in the central plane CP;ρ is the density of the fluid; andΔp is the pressure drop across the butterfly valve50within the conduit32.

FIG.7Bis a graph60illustrating flow coefficient versus valve angle β for each of the butterfly valve50and a comparative butterfly valve, according to an embodiment of the present disclosure. The valve angle β is shown in the abscissa in degrees and the torque coefficient is shown in the ordinate. The graph60illustrates the flow coefficient CF1versus valve angle β for the butterfly valve50, and a flow coefficient CFversus valve angle β for the comparative butterfly valve. The flow coefficient of each of the butterfly valve50and the comparative butterfly valve varies with the valve angle β. For similar flow conditions within the conduit32and for any value of the valve angle β, a maximum difference between the flow coefficient CF1of the butterfly valve50and the flow coefficient CFof the comparative butterfly valve is at most 10%. In some cases, the maximum difference between the flow coefficient CF1of the butterfly valve50and the flow coefficient CFof the comparative butterfly valve is at most 8%. As the maximum difference between the flow coefficient CF1of the butterfly valve50and the flow coefficient CFof the comparative butterfly valve is at most 10%, it is evident that there is minimal flow capacity reduction across an operating range of the butterfly valve50.

Specifically, the flow coefficient CF1of the butterfly valve50is less than the flow coefficient CFof the comparative butterfly valve by at most 10%. As the maximum difference between the flow coefficient CF1of the butterfly valve50and the flow coefficient CFof the comparative butterfly valve is at most 10%, it is evident that there is minimal flow capacity reduction across the operating range of the butterfly valve50. Hence, considering the comparison of the peak value PV1of the torque coefficient CT1of the butterfly valve50with the peak value PV of the torque coefficient CTof the comparative butterfly valve, and the comparison of the flow coefficient CF1of the butterfly valve50with the flow coefficient CFof the comparative butterfly valve, it can be stated that the butterfly valve50may provide a desirable torque loading as well as an achievable flow capacity across the operating range of the butterfly valve50.

Referring toFIGS.1to7B, the first lobe116, the second lobe126, and the third lobe132may provide the butterfly valve50with the desirable optimized geometry that results in the reduced torque loading along with minimal flow capacity reduction across the operating range of the butterfly valve50. This may provide an improved performance of the butterfly valve50as well as the low pressure compressor14or high pressure compressor15when installed for bleeding purposes in the gas turbine engine10. Further, the inclusion of the first lobe116, the second lobe126, and the third lobe132does not restrict any movement of the butterfly valve50, thereby making it possible to be easily controlled by a valve actuator (not shown).

While the reduced torque loading is achieved with appropriate consideration for flow discharge requirements across the operating range of the butterfly valve50, a size of the valve actuator may also be relatively reduced.

FIG.8is a perspective top view of a butterfly valve50′, according to another embodiment of the present disclosure.FIG.9is a top view of the butterfly valve50′ ofFIG.8, according to an embodiment of the present disclosure.FIG.10Ais a side view of the butterfly valve50′, as viewed from a first side B1(shown inFIG.8), according to an embodiment of the present disclosure.FIG.10Bis a side view of the butterfly valve50′, as viewed from a second side B2(shown inFIG.8) opposite to the first side B1, according to an embodiment of the present disclosure.FIG.11Ais a perspective front view of the butterfly valve50′, according to an embodiment of the present disclosure.FIG.11Bis a perspective rear view of the butterfly valve50′, according to an embodiment of the present disclosure.

Referring toFIGS.8to11B, the butterfly valve50′ is substantially similar to the butterfly valve50shown inFIGS.3A to6B, with common components being referred to by the same numerals. Moreover, a functional advantage of the butterfly valve50′ is substantially the same as that of the butterfly valve50. The butterfly valve50′ includes a valve body100′ which is substantially similar to the valve body100shown inFIGS.3A to6B. However, the valve body100′ includes a second major surface106′ (instead of the second major surface106shown inFIG.3A). The second major surface106′ is equivalent to the second major surface106shown inFIG.3A. The second major surface106′ includes a second central line108′ (instead of the second central line108) extending along the length of the shaft52parallel to the longitudinal axis LA.

The valve body100′ further includes a second lobe126′ (instead of the second lobe126shown inFIG.3A). The second lobe126′ is substantially similar to the second lobe126shown inFIG.3A. The second lobe126′ partially forms the second major surface106′ and extends at least partially from the leading portion112towards the second central line108′ along the transverse axis TA. The second lobe126′ further extends at least partially along the longitudinal axis LA. The second lobe126′ includes a second peak edge128′ (instead of the second peak edge128shown inFIG.3A) that is disposed proximal to the leading portion112. The second lobe126′ ascends from the leading portion112to the second peak edge128′ at least along the second direction D2(shown inFIGS.10A and10B) and descends from the second peak edge128′ towards the second central line108′. The first lobe116and the second lobe126′ are disposed on opposing sides of the central plane CP.

The second lobe126′ further includes a second convex surface130′ (instead of the second convex surface130shown inFIG.3A) extending from the corresponding leading portion112towards the second central line108′ along the transverse axis TA, such that the second convex surface130′ includes the second peak edge128′.

The valve body100further includes a third lobe132′ (instead of the third lobe132shown inFIG.3A). The third lobe132′ is substantially similar to the third lobe132shown inFIG.3A. The third lobe132′ is spaced apart from each of the first lobe116and the second lobe126′. The third lobe132′ partially forms the second major surface106′ of the valve body100′. The third lobe132′ extends from the trailing portion114towards the second central line108′ along the transverse axis TA. The third lobe132′ further extends at least partially along the longitudinal axis LA. The second lobe126′ and the third lobe132′ are disposed on the same side of the central plane CP. Further, in the illustrated embodiment ofFIGS.8to11B, each of the second lobe126′ and the third lobe132′ is at least partially spaced apart from the perimeter surface110with respect to the longitudinal axis LA. Therefore, as shown inFIGS.8to11B, in the butterfly valve50′, each of the second lobe126′ and the third lobe132′ is not fully continuous with the perimeter surface110.

The third lobe132′ includes a third peak edge134′ (instead of the third peak edge134shown inFIG.3A) that is disposed proximal to the trailing portion114. The third lobe132′ ascends from the trailing portion114to the third peak edge134′ at least along the second direction D2and descends from the third peak edge134′ towards the second central line108′. Each of the first peak edge118, the second peak edge128′, and the third peak edge134′ is rounded. In some embodiments, each of the first peak edge118, the second peak edge128′, and the third peak edge134′ extends parallel to the longitudinal axis LA.

In some embodiments, the third lobe132′ includes a third convex surface136′ (instead of the third convex surface136shown inFIG.3A) extending from the corresponding trailing portion114towards the second central line108′ along the transverse axis TA, such that the third convex surface136′ includes the third peak edge134′.

In some embodiments, the second major surface106′ further includes a central concave surface portion138′ (instead of the central concave surface portion138shown inFIG.3A) extending between the second lobe126′ and the third lobe132′. The central concave surface portion138′ includes the second central line108′. In the illustrated embodiment ofFIGS.8to11B, the central concave surface portion138′ is not adjacent to the perimeter surface110.

The second major surface106′ further includes a first planar surface portion140extending from the perimeter surface110at least along the longitudinal axis LA. The second major surface106′ further includes a second planar surface portion142disposed opposite to the first planar surface portion140. The second planar surface portion142extends from the perimeter surface110at least along the longitudinal axis LA.

The second major surface106′ further includes a first intermediate surface portion144rising from the first planar surface portion140at least along the second direction D2to each of the second lobe126′, the third lobe132′, and the central concave surface portion138′. The first intermediate surface portion144further extends at least partially along the transverse axis TA. The second major surface106′ further includes a second intermediate surface portion146disposed opposite to the first intermediate surface portion144. The second intermediate surface portion146rises from the second planar surface portion142at least along the second direction D2to each of the second lobe126′, the third lobe132′, and the central concave surface portion138′. The second intermediate surface portion146further extends at least partially along the transverse axis TA.

Each of the second lobe126′, the third lobe132′, and the central concave surface portion138′ is at least partially separated from the perimeter surface110by the first planar surface portion140and the second planar surface portion142. In some embodiments, each of the first intermediate surface portion144and the second intermediate surface portion146is at least partially concave. In some other embodiments, each of the first intermediate surface portion144and the second intermediate surface portion146may be partially convex or planar. Further, in some other embodiments, each of the second lobe126′, the third lobe132′, and the central concave surface portion138′ is at least partially separated from the perimeter surface110by a pair of opposing curved surfaces.

FIG.12Ais a graph62illustrating torque coefficient versus valve angle β for each of the butterfly valve50′ and the comparative butterfly valve, according to an embodiment of the present disclosure. The valve angle β is shown in the abscissa in degrees and the torque coefficient is shown in the ordinate. The butterfly valve50′ and the comparative butterfly have the same construction and diameter except that first and second major surfaces of the comparative butterfly valve are planar without any lobes. Therefore, the graph62illustrates a torque coefficient CT2versus valve angle β for the butterfly valve50′, and the torque coefficient CT(also shown inFIG.7A) versus valve angle β for the comparative butterfly valve.

For similar flow conditions within the conduit32, the torque coefficient CT2of the butterfly valve50′ varies with the valve angle β and has a peak value PV2, and the torque coefficient CTof the comparative butterfly valve varies with the valve angle β and has the peak value PV. The peak value PV2of the torque coefficient CT2of the butterfly valve50′ is less than the peak value PV of the torque coefficient CTof the comparative butterfly valve by at least 30%. In some embodiments, the peak value PV2of the torque coefficient CT2of the butterfly valve50′ is less than the peak value PV of the torque coefficient CTof the comparative butterfly valve by at least 35%.

Referring toFIGS.8to12A, it can be stated that the first lobe116, the second lobe126′, and the third lobe132′ together reduce the peak value PV2of the torque coefficient CT2of the butterfly valve50′ by at least 30% relative to the peak value PV of the torque coefficient CTof the comparative butterfly valve. The inclusion of the first lobe116′, the second lobe126′, and the third lobe132′ may cause reduced torque loading on the butterfly valve50′ as compared to that of conventional butterfly valves or the comparative butterfly valve. Thus, the butterfly valve50′ of the present disclosure is aerodynamically optimized for a desirable5torque reduction relative to that of the comparative butterfly valve. This may improve an overall performance of the butterfly valve50′ and the gas turbine engine10in which the butterfly valve50′ is being installed.

FIG.12Bis a graph64illustrating flow coefficient versus valve angle β for each of the butterfly valve50′ and the comparative butterfly valve, according to an embodiment of the present disclosure. The valve angle β is shown in the abscissa in degrees and the torque coefficient is shown in the ordinate. The graph64illustrates the flow coefficient CF2versus valve angle β for the butterfly valve50′, and the flow coefficient CF(also shown inFIG.7B) versus valve angle β for the comparative butterfly valve. For similar flow conditions within the conduit32and for any value of the valve angle β, a maximum difference between the flow coefficient CF2of the butterfly valve50′ and the flow coefficient CFof the comparative butterfly valve is at most 10%. In the illustrated embodiment ofFIG.12B, the maximum difference between the flow coefficient CF1of the butterfly valve50′ and the flow coefficient CFof the comparative butterfly valve is at most 5%. As the maximum difference between the flow coefficient CF2of the butterfly valve50′ and the flow coefficient CFof the comparative butterfly valve is at most 5% to 10%, it is evident that there is minimal flow capacity reduction across the operating range of the butterfly valve50′.

Referring toFIGS.8A to12B, the first lobe116, the second lobe126′, the third lobe132′, the first planar surface portion140, and the second planar surface portion142may provide the butterfly valve50′ with the desirable optimized geometry that results in the reduced torque loading along with negligible flow capacity reduction across the operating range of the butterfly valve50′. This may provide an improved performance of the butterfly valve50′ as well as the low pressure compressor14or the high pressure compressor15when installed for bleeding purposes in the gas turbine engine10.

FIG.13is a front view of a base disc model66having a diameter D equal to the valve body100of the butterfly valve50(shown inFIGS.2A to6B). The base disc model66is used for manufacturing the butterfly valve50ofFIGS.2A to6B. The base disc model66includes a first base major surface68, a second base major surface70opposite to the first base major surface68, and a base perimeter surface72extending between the first base major surface68and the second base major surface70. Each of the first base major surface68and the second base major surface70is planar (without any lobes).

FIG.14is a flowchart illustrating a method200for manufacturing the butterfly valve50ofFIG.2A, according to an embodiment of the present disclosure. The method200may also be used for manufacturing the butterfly valve50′.

Referring toFIGS.3A,13, and14, at step202, the method200includes providing the base disc model66. The base disc model66has a torque coefficient CTBand a flow coefficient CFB. The torque coefficient CTBof the base disc model66is calculated according to Equation 3 provided below:

CTB=(TB)/(DB3*Δ⁢pB)(Equation⁢3)where, CTBis the torque coefficient of the base disc model66;TBis torque applied of the base disc model66to rotate the base disc model66;DBis diameter of the base disc model66; andΔpBis pressure drop across the base disc model66within a conduit.

The flow coefficient CFBof the base disc model66is calculated according to Equation 4 provided below:

CFB=(mB)/(AB*(2*ρ*Δ⁢pB)1/2)(Equation⁢4)where, CFBis the flow coefficient of the base disc model66;“mB” is mass flow rate of a fluid flowing through the conduit housing the base disc model66;ABis area of the base disc model66in a central plane;ρ is the density of the fluid flowing through the conduit; andΔpBis pressure drop across the base disc model66within the conduit.

At step204, the method200further includes providing a plurality of surface splines on the base disc model66to modify the first base major surface68and the second base major surface70in order obtain a plurality of parametrized baseline geometries corresponding to the plurality of surface splines. A surface spline can be understood as a mathematical representation for which it is easy to build an interface that will allow a user to design and control the shape of complex curves and surfaces. At step206, the method200further includes performing, by a simulator software, simulation on the plurality of parametrized baseline geometries based on computational fluid dynamics (CFD) in order to obtain pressure and velocity distributions across various points on each of the plurality of parametrized baseline geometries. The simulator software may output mid-height plane velocity and pressure distributions on each of the plurality of parametrized baseline geometries. The simulator software may reduce computational time for multiple training data simulations.

At step208, the method200further includes exporting, by a solver, simulation data including a mass flow rate of the fluid across each of the plurality of parametrized baseline geometries and a torque applied on each of the plurality of parametrized baseline geometries to form export data. At step210, the method200further includes selecting at least one parameterized base geometry from the plurality of parametrized baseline geometries based on the export data. At step212, the method200further includes creating, by the solver, a surrogate Gaussian process regression model based on the export data and geometrical parameters of each of the at least one parametrized baseline geometry. A surrogate model may refer to a mathematical model that seeks to predict, such as by interpolating or extrapolating a response, or output, based on output values previously acquired from empirical observation and/or mathematical calculations, including calculations using an existing full-physics model. Such surrogate model is generated by using Gaussian process regression model.

At step214, the method200further includes minimizing, by the surrogate Gaussian process regression model, an objective function F2in order to generate geometrical parameters of a butterfly valve model corresponding to the butterfly valve50. The objective function F2includes a torque parameter k2to relate new torque coefficient CTNof the butterfly valve model to the torque coefficient CTBof the base disc model66. The relationship between the new torque coefficient CTNof the butterfly valve model and the torque coefficient CTBof the base disc model66is shown in Equation 5.

The objective function F2further includes a flow parameter k1to relate new flow coefficient CFNof the butterfly valve model to the flow coefficient CFBof the base disc model66. The relationship between the new flow coefficient CFNof the butterfly valve model and the coefficient CFBof the base disc model66is shown in Equation 6.

From Equation 6 and Equation 4, it can be derived that:

DN=(DB/(k⁢1)1/2)(Equation⁢7)where, DNis diameter of the butterfly valve model.

From Equation 5 and Equation 3, it can be derived that:

Equation 7 and Equation 8 show dependence of adjustment in valve characteristics on the torque parameter k2and the flow parameter k1. The objective function F2is calculated based on Equation 7 and Equation 8.

To generate the geometrical parameters of the butterfly valve model corresponding to the butterfly valve50shown inFIG.3A, it is required to minimize a value of the objective function F2shown in Equation 9.

At step216, the method200further includes verifying, by the simulator software, the geometrical parameters of the butterfly valve50based on the mass flow rate across the butterfly valve model and the torque applied on the butterfly valve model. This is to verify desirable pressure and velocity distributions across various points on the butterfly valve50. At step218, the method200further includes manufacturing the butterfly valve50based on the butterfly valve model. Any suitable manufacturing method may be used.

It will be understood that the present disclosure is not limited to the embodiments above-described and various modifications and improvements can be made without departing from the concepts described herein. For example, although the embodiments disclosed relate to a butterfly valve for a gas turbine engine, it will be appreciated that the embodiments may be applied to a range of different applications, in which it is desirable to reduce the actuation torque of a butterfly-type valve. Except where mutually exclusive, any of the features may be employed separately or in combination with any other features and the disclosure extends to and includes all combinations and sub-combinations of one or more features described herein.