Sweeping jet swirl nozzle

An injector head for an anti-icing system may comprise a body having a first surface, a second surface, a face, and an inlet, a first sweeping jet nozzle having a first exit port through the face, wherein the first sweeping jet nozzle comprises a fluid oscillator defining a first sweeping plane of the first sweeping jet nozzle, and a distribution manifold within the body in fluid communication with the inlet and the first sweeping jet nozzle.

FIELD

The disclosure relates generally to vehicles and machinery and, more specifically, to anti-icing systems including nozzles that may be used with aircraft and aircraft engines.

BACKGROUND

In operation, a gas turbine engine nacelle may experience conditions in which icing may occur. For example, an engine nacelle of an aircraft, as well as other parts of the aircraft such as the wing leading edge, may experience the formation of ice when operating in cold or below-freezing temperatures. The formation of such ice may dramatically alter one or more flight characteristics of the aircraft. For example, the formation of ice may deleteriously affect the aerodynamics of the aircraft and add additional undesirable weight, as well as generate a hazard when such ice breaks off and potentially strikes another portion of the aircraft. For example, ice breaking loose from the leading edge of the gas turbine engine nacelle inlet may be ingested by the gas turbine engine and thereby severely damage the rotating fan, compressor, and turbine blades.

SUMMARY

In various embodiments, an injector head for an anti-icing system is disclosed comprising a body having a first surface, a second surface, a face, and an inlet, a first sweeping jet nozzle having a first exit port through the face, wherein the first sweeping jet nozzle comprises a fluid oscillator defining a first sweeping plane of the first sweeping jet nozzle, and a distribution manifold within the body in fluid communication with the inlet and the first sweeping jet nozzle.

In various embodiments, the fluid oscillator is bi-stable. In various embodiments, the fluid oscillator is one of a feedback free oscillator, a single feedback oscillator, or a double feedback oscillator. In various embodiments, the injector head comprises a second sweeping jet nozzle and a third sweeping jet nozzle, the second sweeping jet nozzle having a second sweeping plane and a second exit port through the face, the third sweeping jet nozzle having a third sweeping plane and a third exit port through the face. In various embodiments, the first sweeping plane, the second sweeping plane, and the third sweeping plane are co-planar. In various embodiments, the first sweeping plane is perpendicular to the second surface and the second sweeping plane is disposed at a non-orthogonal angle to the second surface. In various embodiments, the first exit port has a first diameter, the second exit port has a second diameter, and the third exit port has a third diameter, wherein the second diameter is greater than the first diameter and less than the third diameter. In various embodiments, the non-orthogonal angle is between 10° and 80°. In various embodiments, the first sweeping jet nozzle has a first offset angle, the second sweeping jet nozzle has a second offset angle, and the third sweeping jet nozzle has a third offset angle, wherein the first offset angle is greater than the second offset angle and the second offset angle is greater than the third offset angle.

In various embodiments an anti-icing system for an annular inlet of a gas turbine engine is disclosed comprising a D-duct comprising an inlet lip and a bulkhead enclosing a mass of air within an annular space therebetween, the inlet lip having an inner lipskin and an outer lipskin, a high pressure source of hot gas, a conduit coupled at a first end to the high pressure source of hot gas, wherein an opposite end penetrates the bulkhead at a penetration point, an injector head within the D-duct coupled at the opposite end of the conduit and proximate the penetration point, the injector head in fluid communication with the high pressure source of hot gas and comprising, a body having a first surface, a second surface, a face, and an inlet, a first sweeping jet nozzle having a first exit port through the face, wherein the first sweeping jet nozzle comprises a fluid oscillator defining a first sweeping plane of the first sweeping jet nozzle, and a distribution manifold within the body in fluid communication with the inlet and the first sweeping jet nozzle.

In various embodiments, the penetration point is located between 30% to 70% of a bulkhead height from an inboard edge of the bulkhead. In various embodiments, a centerline of the first sweeping jet nozzle is tangential to the inner lipskin. In various embodiments, the fluid oscillator is one of a bi-stable feedback free oscillator, a bi-stable single feedback oscillator, or a bi-stable double feedback oscillator. In various embodiments, the injector head further comprises a second sweeping jet nozzle and a third sweeping jet nozzle, the second sweeping jet nozzle having a second sweeping plane and a second exit port through the face, the third sweeping jet nozzle having a third sweeping plane and a third exit port through the face, wherein the first exit port is proximate the inlet and the second exit port is relatively between the third exit port and the first exit port. In various embodiments, the first sweeping plane is perpendicular to the second surface and the second sweeping plane is disposed at a non-orthogonal angle to the second surface. In various embodiments, the non-orthogonal angle is between 10° and 80°. In various embodiments, the first sweeping plane is configured to sweep the bulkhead between the inner lipskin and the outer lipskin and wherein the second sweeping plane is configured to intersect a corner of the bulkhead. In various embodiments, the first exit port has a first diameter, the second exit port has a second diameter, and the third exit port has a third diameter, wherein the second diameter is greater than the first diameter and less than the third diameter. In various embodiments, the first sweeping jet nozzle has a first offset angle, the second sweeping jet nozzle has a second offset angle, and the third sweeping jet nozzle has a third offset angle, wherein the first offset angle is greater than the second offset angle and the second offset angle is greater than the third offset angle.

In various embodiments, an anti-icing method for a gas turbine engine is disclosed. The method may comprise a D-duct comprising an inlet lip and a bulkhead enclosing a mass of air within an annular space therebetween, the inlet lip having an inner lipskin and an outer lipskin a high pressure source of hot gas an injector head comprising a sweeping jet nozzle, and introducing the high pressure hot gas into the mass of air within the D-duct via the injector head to entrain the mass of air in a circulating flow within the D-duct, and pumping the circulating flow by at least one of sweeping a jet of the sweeping jet nozzle in a first sweeping plane along the bulkhead between the inner lipskin and the outer lipskin or sweeping the jet in a second sweeping plane intersecting a corner of the bulkhead and the inner lipskin.

DETAILED DESCRIPTION

In various embodiments and with reference toFIG. 1, a gas turbine engine10is provided and housed within a nacelle12, of which some components are omitted for clarity. Gas, such as air, enters the gas turbine engine10through an annular inlet section14, between the cap16(or spinner) of the engine and the annular inlet lip18or annular housing which constitutes the forward most section of the engine inlet housing20of nacelle12. Gas turbine engine may produce thrust by: (i) compressing a gas to a core air flow in a compressor section22forward of a combustor section23positioned with the gas turbine engine core, burning incoming core air flow and fuel within the combustor section23, and expanding the combustor exhaust through a turbine section24aft of the combustor section; and (ii) compressing and passing a large mass bypass air flow of inlet air through the fan section21of the gas turbine engine. Hot, high-pressure exhaust gases from the turbine section24of the engine10pass through exhaust outlet25and out the rear of the engine10. The compressed bypass fan air flows past the outside of the engine core within the engine nacelle cowl housing12and exits at the rear of the engine10.

In various embodiments and when operating in flight under icing conditions, ice may tend to form on the inlet lip18of nacelle12. The ice may alter the geometry of the inlet area between the inlet lip18and the spinner16tending thereby to disrupt airflow within annular inlet section14and reducing gas turbine engine10performance. In various embodiments, ice may periodically break free from these components and may be ingested into fan section21or compressor section22tending thereby to damage internal components of engine10such as, for example, stator vanes, rotor blades, radiators, ducting, etc.

In various embodiments and with additional reference toFIGS. 2 and 3, an anti-icing system may comprise a conduit26coupled at a first end28to a bleed air source of gas turbine engine10which provides relatively hot, high pressure, bleed air. In various embodiments, the bleed air source temperature may be between 400° F. and 1200° F. and the source pressure may be between 30 psig and 100 psig. The other end of conduit26passes through inlet housing20and penetrates D-duct300through a bulkhead302which encloses a quantity of air within the annular space created by bulkhead302and inlet lip18. Conduit26is fluidly coupled to an injector head304which extends into D-duct300from bulkhead302. D-duct300may extend a distance L between bulkhead302and the leading edge310of inlet lip18. Body306of injector head304comprises one or more sweeping jet nozzles312and may extend into D-duct300a distance D between 30% of L and 70% of L. In various embodiments, body306may comprise between one and four sweeping jet nozzles312.

In various embodiments and with additional reference toFIG. 4, a schematic perspective of the details of D-duct300of the anti-icing system is shown illustrating circulating D-duct flow400. Cool, moisture-laden, free-stream air scrubs the exterior of the inlet lip18skin, with impinging super-cooled droplets tending to accumulate as ice. Injector head304injects the bleed air through the sweeping jet nozzles312into the mass of air within the D-duct300and entrains the air mass to induce flow400in a rotational circulatory motion. The relatively hot and high pressure bleed air mixes with mass of air within the D-duct300to increase the temperature of the D-duct air mass to an intermediate temperature sufficient to preclude the formation of ice along inlet lip18. In various embodiments, the injector head304may be oriented with a centerline of sweeping jet nozzles312and/or an injector head face relatively tangential to the curve of the D-duct300. In this regard, bleed air exiting the sweeping jet nozzles may graze the inner lipskin404before eventually impacting the interior surface of the inlet lip18. Bleed air exiting the sweeping jet nozzles312may impact an area of the interior surface of inlet lip18in line with the jet flow from sweeping jet nozzles312tending thereby to elevate the temperature of the impact area (i.e., a hot spot) relative to the remaining area of the inlet lip18. In various embodiments, the hotspot may cover an area of the outer lipskin402.

As bleed air is injected via injector head304, a portion of D-duct flow400may recirculate within D-duct300while a portion of D-duct flow400may exit the D-duct300through exhaust ports308(FIG. 2) to the atmosphere. At steady state, the hot air injection inflow into the D-Duct through the injector head equals outflow of spent air through the exhaust ports308. In various embodiments, ejector-like pumping within enclosed geometry of the D-duct300results in the circulating flow400inside the D-duct300which may be several times larger than the injection flow rate. Stated another way, the resulting circulating flow400may be described as a self-communicating ejector wherein the D-Duct flow being pumped in the nozzle region circulates around within the inlet lip, to once again re-enter the nozzle region. Circulation enhances heat transfer, but skews velocity towards the outer lipskin402, thereby favoring of heat rejection to outer lipskin402. Stated another way, the circulating flow400inside the D-duct tends to result in a higher speed flow near the outer lipskin402of the inlet lip18and a lower speed flow near the inner lipskin404of inlet lip18. The magnitude of the circulating flow may be limited by D-duct wall friction and drag at the injector head304. In various embodiments, the slowest flow is observed proximate the corner406between the inner lipskin404and the bulkhead302. In various embodiments, corner406may comprise an acute angle tending to benefit heating of the inner lipskin404toward a throat station of the inlet.

With additional reference toFIG. 5, body geometries and orientations of an injector head304are shown with relation to bulkhead302. Body306of injector head304extends from bulkhead302along a perpendicular centerline500that is perpendicular to the bulkhead302. In various embodiments, body306may be oriented at an angle α relatively away from the centerline. Stated another way, body306may be “bent” proximate the penetration point502at bulkhead302. In like regard and in various embodiments, body306may be rotated to an angle relative to a perpendicular plane extending from bulkhead302. Bulkhead has a height H defined between an inboard edge504and an outboard edge506and the penetration point502may be located between 30% to 70% of H taken as taken from the inboard edge504(proximate the inner lipskin404).

With additional reference toFIG. 6, a planar view of body306of injector head304is illustrated with XYZ-axes for reference. The upper surface612(i.e., a first surface) and lower surface614(i.e., a second surface) of body306are parallel to the XY-plane. Bleed air600enters inlet602and exits from each of the sweeping jet nozzles312(FIG. 3) through exit ports in the face610of body306as a first jet604from a first port, a second jet606from a second port, and a third jet608from a third port respectively. In various embodiments, the exit ports may be rectangular or elliptical with the long axis aligned with direction of sweeping (e.g., the long axis parallel the sweeping plane), or may be circular as shown inFIG. 7.

With additional reference toFIG. 7, body306of injector head304is shown in cross section through the XY-plane. Bleed air600enters inlet602and flows through distribution manifold700which supplies bleed air to each of the sweeping jet nozzles312. Each sweeping jet nozzle312comprises fluid oscillator712. In various embodiments, fluid oscillator712may be a bi-stable fluidic oscillator such as a feedback free oscillator, a single feedback oscillator, or, as illustrated, a double feedback oscillator. Fluid oscillator712has a converging inlet nozzle702which feeds a chamber706having a diverging section704opening into a first feedback channel708, a second feedback channel710, and a throat718of a divergent exit port720. Primary jet722enters from distribution manifold700into converting inlet nozzle702and is injected along the centerline of chamber706. The primary jet722may tend to attach to the wall of diverging section704of the chamber706and encounter edges714and/or716of throat718.

In response, edges714and716split and turn portion of primary jet722to a control flow724returning through either of the respective second feedback channel710or first feedback channel708to interact with the primary jet722. Introducing the control flow724to the primary jet722may tend to cause the primary jet722to release from the proximate wall of the diverging section704of the chamber706and travel to the opposite wall. This process reverses periodically due to the feedback of the control flow724tending thereby to result in planar oscillation of the primary jet722flow through the fluid oscillator712with respect to the plane of the control flow724in the feedback channels708and710. In this regard, each of the jets604,606, and608may be constrained to oscillate in the plane extending along a centerline of the fluid oscillator712and through each of the feedback channels, such as the first feedback channel708and the second feedback channel710. Stated another way, the sweeping plane may be defined by the geometry of the fluid oscillator. The oscillations of the jets may sweep across an angle θ (i.e., a sweeping angle) defined by the geometry of the walls of an exit port such as exit port720. In various embodiments, a feedback channel may describe a curve or may comprise rounded the interior corners, or may be connected slightly downstream of throat706.

With reference toFIGS. 8A through 8C, in various embodiments sweeping jet nozzles may be arranged within injector head (304,304′,304″) to configure the sweeping plane of the first jet604, the second jet606, and the third jet608. The sweeping plane may be rotated about the centerline of the respective fluid oscillator and/or exit port. The sweeping plane of the jets may be perpendicular to the upper surface (612,612′,612″) and lower surface (614,614′,614″) as shown by arrows800(i.e., sweeping along the Z-axis) or may be parallel to the upper surface612and the lower surface614as shown by arrows802(i.e., sweeping along the Y-axis). In various embodiments, the sweeping plane of each of the jets may be uniform across the jets as shown inFIGS. 8A and 8Bor, as inFIG. 8Cmay vary between the jets. The centerline of each of the fluid oscillators may be directed parallel with the X-axis. With particular reference toFIGS. 8A and 8C, the sweeping action tends to improve the pumping in the relatively low speed region at the corner406of bulkhead302and inner lipskin404. With particular reference toFIG. 8D, a simplified D-duct flow field corresponding to the sweeping jet nozzles arrangement ofFIG. 8Bis illustrated. The centerline of each of the fluid oscillators of injector head304are directed along a line804relatively tangent to the inner lipskin404of the D-duct300and describing generally a mean jet flow path for each of the jets. Stated another way, the sweeping plane of each of the sweeping jet nozzles may be co-planar. The sweeping plane extends perpendicular to the page and along line804tending thereby to create a hot spot at impact area806across the swept area of axial thickness of the D-duct. In various embodiments, the sweeping action tends to mitigate the severity of the outer lipskin hot spot. The sweeping action tends to improve pumping in the relatively low speed region at the corner of the bulkhead302and the inner lipskin404.

In various embodiments, a sweeping jet nozzle may be oriented such that the jet sweeps, and thereby pumps, a larger portion of the D-duct cross section. A sweeping plane may be aligned to improve pumping in the relatively low speed corner of the bulkhead and inner lipskin for example by sweeping a jet along the bulkhead or in a sweeping plane intersecting the corner of the bulkhead and the inner lipskin. In various embodiments, a sweeping plane may be aligned to be over a portion of the inner lipskin tending thereby to preferentially heat the inner lipskin and inhibit internal flow separation from the inner lipskin.

In various embodiments and with reference toFIG. 9A, an injector head900having features, geometries, construction, materials, manufacturing techniques, and/or internal components similar to injector head304is illustrated in accordance with various embodiments. Injector head900comprises a first sweeping jet nozzle901, a second sweeping jet nozzle902, and a third sweeping jet nozzle903. The exit port diameter of each of the sweeping jet nozzles is tailored such that the port218of the second sweeping jet nozzle902has an intermediate diameter between the relatively smaller port916of first sweeping jet nozzle901and the relatively larger port920of third sweeping jet nozzle903. The sweeping plane908(i.e., a first sweeping plane) of the first sweeping jet nozzle901is configured perpendicular to the lower surface914(i.e., configured to sweep along the XZ-plane). In various embodiments, the first sweeping plane is configured to sweep along the bulkhead between the inner lipskin and the outer lipskin. The sweeping plane910(i.e., a second sweeping plane) of the second sweeping jet nozzle902is configured at a non-orthogonal angle to the lower surface914(e.g., configured to sweep along a plane set between 10° and 80° to lower surface914). In various embodiments, the sweeping plane910of the second sweeping jet nozzle902is set about 45° to lower surface914. The sweeping plane912of third sweeping jet nozzle903is configured parallel to lower surface914(i.e., configured to sweep along the XY-plane). In various embodiments, each of the centerlines of the fluid oscillators of the first sweeping jet nozzle901, second sweeping jet nozzle902, and third sweeping jet nozzle903may be rotated about the Y-axis to describe an offset angle between the X-axis and the centerline of the fluid oscillator. Stated another way, the offset angle may describe an inclination of the sweeping plane relative to a lower surface914of the injector head900.

With additional reference toFIG. 9B, a simplified D-duct flow field corresponding to the sweeping jet nozzles arrangement ofFIG. 9Ais illustrated. First sweeping jet nozzle901has a centerline with a first offset angle shown by centerline904describing the mean flow path of the first sweeping jet nozzle901. The relatively small port916diameter tends to mitigate hot spot formation and overheating from the comparatively short distance of the mean flow path from the injector head900to the first impact area922. The sweeping plane908of the first sweeping jet nozzle901is relatively parallel to bulkhead302and tends to accelerate flow along the relatively low speed region at the corner406of the bulkhead302and the inner lipskin404by sweeping along the bulkhead. Second sweeping jet nozzle902has a centerline with a second offset angle (relatively less than the first offset angle shown by centerline904) shown by centerline905describing the mean flow path of the second sweeping jet nozzle902and having a second impact area924relatively downstream (with regard circulating flow400within D-duct300) of the first impact area922. In various embodiments, the sweeping plane910of the second sweeping jet nozzle902may intersect the corner406of the bulkhead302and the inner lipskin404and thereby tend to increase the pumping action in the corner. Third sweeping jet nozzle903has a centerline with a third offset angle (relatively less than the second offset angle shown by centerline905) shown by centerline906describing the mean flow path of the third sweeping jet nozzle903and having a third impact area926relatively downstream (with regard to circulating flow400within D-duct300) of the second impact area924and the first impact area922. In various embodiments, the sweeping plane912of the third sweeping jet nozzle903may be oriented to promote rapid mixing of the injected flow with the faster moving region of D-duct flow proximate the outer lipskin402. In various embodiments, the relative separation of the first impact area922, the second impact area924, the third impact area926and the non-uniform configuration of the first sweeping plane908, the second sweeping plane910, and the third sweeping plane912tend to inhibit hot spot formation and reduce outer lipskin402temperatures.