Patent Publication Number: US-6702873-B2

Title: High particle separation efficiency system

Description:
TECHNICAL FIELD 
     The present invention relates generally to aeronautical vehicle systems, and more particularly to a method and apparatus for separating particles from an induced fluid within an aeronautical vehicle engine. 
     BACKGROUND OF THE INVENTION 
     During operation of an aeronautical vehicle, fluids are forced into an engine and are used to generate energy to propel the vehicle. The fluids may contain undesirable particles, such as sand and dust, which can cause degradation of engine components. In order to prevent the degradation of engine components, the undesirable particles are separated from the fluids using an inertial inlet particle separator. 
     Referring now to FIG. 1, a quarter cross-sectional view of a traditional inertial inlet particle separator  10  is shown. The separator  10  includes a duct system  12  having a scavenge channel  14  that forms an in-line fluid path with a fluid inlet  18 , represented by arrow  16 , and a clean intake channel  20  that branches off from the in-line fluid path  16 . The duct system  12  is divided via a splitter  22  to form the scavenge channel  14  and the clean intake channel  20 . A clean intake channel opening  24  is defined by the splitter  22  on a first side  26  and a hub  28  on a second side  30 . 
     Fluid contaminated with particles has a higher inertia than fluid without particles. This being the case, contaminated fluid tends to flow straight into the scavenge channel  14  rather than over and around the hub  28 , which has a radius of curvature with a tangential angle  32 . The angle  32  is generally defined by two vectors lying tangentially on the innermost curvatures of side  30 , intersecting over hub  28  at a point  36 . The contaminated fluid is guided from the scavenge channel into a blower where it is then discharged. Relatively, uncontaminated fluid flows into the clean intake channel  20 , over the hub  28 , where it is then further guided into the engine. Approximately, 15-25% of the fluid entering the fluid inlet  18 , containing larger captured particles, enter the scavenge channel  14 , while the remaining fluid and lighter particles enters the clean intake channel  20 . Thus, a small percentage of particles enter the engine through the clean intake channel  20 , thereby protecting engine componentry. 
     Particle separation efficiency may be minimally increased by decreasing the size of the clean intake channel opening  24  or by decreasing the angle  32  between a fluid inlet portion  34  of the system  12  and the hub  28 . While both methods of increasing efficiency are effective, both methods have an adverse effect of raising the pressure loss of the air entering the engine, with an attendant decrease in power and increase in fuel consumption. Also, the separator  10  has a fixed geometry, such that in order to alter or adjust performance of the separator  10 , the separator  10  needs to be redesigned and remanufactured. The redesign and remanufacturing of the separator  10  results in additional costs. Additionally, being that the separator  10  is rigid the separator is unable to compensate for changing contamination conditions, thereby limiting performance characteristics of the separator  10 . 
     There is a continuous effort to improve the functionality and efficiency of aeronautical vehicles. Therefore, it would be desirable to provide an improved method and apparatus for separating particles from an induced fluid within an aeronautical vehicle engine. The method and apparatus should provide the ability to adjust particle separation efficiency and pressure loss of the separator. 
     SUMMARY OF THE INVENTION 
     The foregoing and other advantages are provided by a method and apparatus for separating particles from an induced fluid within an vehicle engine. An inertial inlet particle separator system for an aeronautical vehicle engine is provided. The system includes a particle sensor that generates a contamination signal. An inertial inlet particle separator is also included in the system and has a fluid parameter adjusting system mechanically coupled within the inertial inlet particle separator. A controller is electrically coupled to the particle sensor and the fluid parameter adjusting system. The controller adjusts a fluid parameter of the inertial inlet particle separator in response to the contamination signal. A method of performing the same is also provided. 
     One of several advantages of the present invention is that it provides an improved apparatus and method for separating particles from an induced fluid within an aeronautical vehicle engine by providing an ability to adjust fluid parameters within the inertial inlet particle separator in response to a contamination level. The aforementioned allows for relatively high efficiency of fuel consumption and high power during low induced fluid contamination levels and relatively high engine protection during high contamination levels. 
     Another advantage of the present invention is that it provides flexibility in the manner as to which the fluid parameters are adjusted including altering channel wall shape, splitter length, clean fluid intake opening size, and various other alterable fluid parameters. The flexibility allows for increased fine-tuning of efficiency and power. 
     Furthermore the present invention allows for fluid flow adjustments during multiple operating speeds of travel. Adjustable fluid flow allows the amount of fluid being discharged to be limited at higher travel speeds, which increases power and decreases fuel consumption when because of inertial effects typically a larger portion of the induced fluid tends to be discharged. Also, adjustable fluid flow allows the present invention to increase fluid flow into an intake portion of an engine and maintain power, rather than experiencing a reduction in power due to a higher contaminated equivalent fluid flow. 
     The present invention itself, together with attendant advantages, will be best understood by reference to the following detailed description, taken in conjunction with the accompanying figures. 
    
    
     BRIEF DESCRIPTION OF THE DRAWING 
     For a more complete understanding of this invention reference should now be had to the embodiments illustrated in greater detail in the accompanying figures and described below by way of examples of the invention wherein: 
     FIG. 1 is a quarter cross-sectional view of a traditional inertial inlet particle separator; 
     FIG. 2 is a side view of an aeronautical vehicle having a turboshaft engine that utilizes an inertial inlet particle separator system in accordance with an embodiment of the present invention; 
     FIG. 3 is a cross-sectional view of the turboshaft engine utilizing the inertial inlet particle separator system in accordance with an embodiment of the present invention; 
     FIG. 4 is a quarter cross-sectional view of an inertial inlet particle separator in accordance with an embodiment of the present invention; and 
     FIG. 5 is a logic flow diagram illustrating a method of separating particles from an induced fluid within an aeronautical vehicle engine. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     In each of the following figures, the same reference numerals are used to refer to the same components. While the present invention is described with respect to a method and apparatus for separating particles from an induced fluid within an aeronautical vehicle engine, the present invention may be adapted to be used in various systems including: automotive vehicle systems, control systems, aeronautical vehicle systems, or other applications requiring the separation of particles within a fluid. The aeronautical vehicle systems may include: a turboshaft engine, a turbine engine, or a turboprop engine. The aeronautical vehicles may include helicopters, planes, or aircraft having fixed wing or tilt wing configurations or tilt rotor configurations. 
     In the following description, various operating parameters and components are described for one constructed embodiment. These specific parameters and components are included as examples and are not meant to be limiting. 
     Also, in the following description the terms “contaminated fluid” and “clean fluid” are terms used to distinguish between a fluid that is relatively dirty as compared to another fluid that is relatively clean. The present invention separates an induced fluid into a contaminated fluid and a clean fluid. The contaminated fluid has larger particles, a larger number of particles, or a combination thereof as compared to the clean fluid. 
     Additionally, although the present invention is described with respect to an inertial inlet particle separator system operating in air and therefore separating contaminated air from clean air, the present invention may be applied to inertial particle separators operating in or utilizing other fluids. For example, a fluid may be in the form of a liquid rather than air. 
     Referring now to FIG. 2, a side view of an aeronautical vehicle  50  having a turboshaft engine  52  that utilizes an inertial inlet particle separator system  54  in accordance with an embodiment of the present invention is shown. The engine  52  compresses atmospheric air to elevate the air pressure, adds heat, and exhausts the compressed high pressure air through a series of turbines (not shown). The turbines extract work from the high pressure air, which in turn propels vehicle  50 . Typically, air is induced into the engine  52  under ambient conditions and is exhausted from the engine  52  at ambient conditions. When air is induced at lower pressures than ambient the engine works harder to produce the same amount of power that is created at ambient pressures. The increase in work results in increased fuel consumption. The system  54  efficiently separates induced fluid into contaminated fluid and clean fluid for various contamination conditions to minimize loss in air pressure and minimize fuel consumption, which is further described in detail below. 
     Referring now to FIG. 3, a cross-sectional view of the engine  52  utilizing the system  54  in accordance with an embodiment of the present invention is shown. The system  54  includes an inertial inlet particle separator  56  having a fluid parameter adjusting system  58 , a particle sensor  60 , and an engine controller  62 . Induced air, represented by arrows  64 , enters the separator  56  and is split into a contaminated fluid  66  and a clean fluid  68  by the parameter adjusting system  58 . The contaminated fluid  66  follows a contaminated fluid flow path  69  and the clean fluid  68  follows a clean fluid flow path  70 . The sensor  60  determines the contamination level of the clean fluid  68  and generates a contamination signal. The controller  62  signals the parameter adjusting system  58  to adjust a clean fluid parameter in response to the contamination signal. The adjustment of a clean fluid parameter alters the amount of contaminated fluid  66  that is filtered from the induced fluid  64  and discharged from the engine  52  versus being used by the engine  52  to generate power. 
     A clean fluid parameter may include adjusting a fluid pressure, a fluid flow path, or a fluid volume. A clean fluid parameter may also include adjusting a fluid channel characteristic such as: a fluid inlet opening size, a fluid inlet shape, a fluid inlet orientation, a channel wall shape, a channel wall size, or various other channel characteristics known in the art. Although, the present invention is described as adjusting a clean fluid parameter an induced fluid parameter, a contaminated fluid parameter, or other fluid parameter may be adjusted. 
     The sensor  60  may be a side optical device, a laser doppler velocimetry device, a laser two focus velocimetry device, a thermocouple, a “sand sniffer” in combination with a particle analyzer, or other particle sensing device known in the art. The sensor  60  measures particle concentration in the clean fluid  68  and generates the contamination signal. The sensor  60  is coupled to the clean fluid channel  74  downstream of the splitter  76 . 
     The controller  62  may be microprocessor based such as a computer having a central processing unit, memory (RAM and/or ROM), and associated input and output buses. The controller  62  may be a portion of a central vehicle main control unit, an engine control unit, an interactive vehicle dynamics module, or a stand-alone controller. The controller  62  may also be simply solid-state digital or analog logic devices. 
     Referring now to FIGS. 4, a quarter cross-sectional view of the separator  56  in accordance with an embodiment of the present invention is shown. The separator  56  includes a fluid inlet  71 , a scavenge channel  72 , and a clean fluid channel  74 . The induced fluid  64  enters the fluid inlet  71  and is divided by an adjustable splitter  76  into the contaminated fluid  66  and the clean fluid  68 , which are guided into the scavenge channel  72  and the clean fluid channel  74 , respectively. The clean fluid  68  flows over an adjustable hub  78  through a clean fluid intake opening  79  to the clean fluid channel  74 . The clean fluid intake opening  79  has an inner width W, which may be altered when adjusting a clean fluid parameter. 
     Referring now to FIGS. 3 and 4, the parameter adjusting system  58  includes the splitter  76  and the hub  78 . Both the splitter  76  and the hub  78  are manipulated via shape memory alloy actuators  82  and worm gears  84 . The actuators  82  rotate turning the worm gears  84  and in turn translating the splitter  76  and repositioning the hub  78 . Although, the present invention uses actuators  82  and worm gears  84  other mechanical devices known in the art may be used in adjusting the splitter  76  and the hub  78 . The inner surface  83  of the hub  78 , for this illustrated embodiment, includes a series of plates  85 . As the worm gear is rotated, the series of plates  85  reorient themselves into different rigid shapes. The series of plates  85  are formed of lightweight rigid materials known in the art. 
     Both the adjustable splitter  76  and the adjustable hub  78  may have adaptive structures, as illustrated by surface  80  to allow for adjusting a clean fluid parameter. Adaptive structures may be of various form. One embodiment of the present invention is as shown, where the actuators  82  contain adaptive structures, which in this stated embodiment are shaped memory alloys. Heat is applied at to the shape memory alloys, causing the alloys to change shape thereby turning the worm gears  84  and translating or reorienting the splitter  76  and the hub  78 . Various other adaptive structure embodiments may be applied such as piezo-electric devices rather than shape memory alloys, which have a faster response time and a smaller throw. Another example, is to replace the series of plates  85  with adaptive structures such as the shape memory alloys and apply electrical current or heat directly to the hub  86  without using the actuators  82  and worm gears  84 . Adaptive structures may therefore be utilized in translating and reorienting the splitter  76  and the hub  78  as stated above or by using other adaptive structure methods known in the art. 
     Although the parameter adjusting system  58  is described as including the splitter  76  and the hub  78 , the system  58  may include only one of the above or may include other similar fluid parameter adjusting apparatuses, as to be able to adjust a fluid parameter within an inertial inlet particle separator. 
     The hub  78  has a variable geometry in that it forms various curved surfaces within the separator  56 . For example, the hub  78  may be reoriented from a first position  86  to a second position  88 . In the first position  86  fluid flows over the hub  78  around a radius having a tangential angle  89  versus around a radius having a tangential angle  90  for the second position  88 . When the hub  78  is in the first position  86  versus the second position  88  there is a lower separation efficiency and lower loss exhibited, being that the width W is smaller. The amount of fluid entering the clean fluid channel  74  is restricted since the fluid has a more acute angled hub to pass around and a smaller opening  79  to enter. 
     The splitter  76  may be translated in a fore or aft direction. For example, the splitter  76  may be translated from a fore position  91  to an aft position  92 . The translation of the splitter  76  alters the size of the width W. In the fore position  91 , the width W is small, therefore reducing the amount of contaminants flowing into the clean fluid channel, as preferred in high contamination conditions. High contamination conditions may include vehicle take off, hot refueling, and low altitude hover and cruise periods. In the aft position  92 , the width W is relatively larger, allowing increased fluid flow into the clean fluid channel, as in low contamination conditions. Low contamination conditions may include hovering at a relatively high distance above ground level, taking off and landing on prepared runways, or during normal cruising periods. Although, the splitter  76  is illustrated as being translated in a fore or aft direction, the splitter may be translated in other directions. 
     Referring now to FIG. 5, a logic flow diagram illustrating a method of separating particles from an induced fluid  64  within the engine  52 , is shown. 
     In step  100 , a fluid is induced into the separator  56 . The fluid is typically air from the atmosphere as described above containing particles such as sand or dust. 
     In step  102 , a contaminated portion, the contaminated fluid  66 , of the induced fluid  64  is inertially guided into the scavenge channel  72 . 
     In step  104 , a clean fluid portion, the clean fluid  68 , of the induced fluid  64  is guided into the clean fluid channel  74 . 
     In step  106 , the particle sensor  60  determines a contamination level of the clean fluid  68  and generates the contamination signal. Particle sensor  60  generates the contamination signal in response to the quantity and size of particles entering the clean fluid intake opening  79 . When the particle sensor  60  is used in a different location within the separator  56 , of course, other quantities would be measured. 
     In step  108 , the controller  62  adjusts a clean fluid parameter in response to the contamination signal. Controller generates a particle description signal. The controller  62 , in response to the particle description signal determines whether to translate the splitter  76  or reorient the hub  78 . Upon adjusting the clean fluid parameter the controller  62  returns to step  100 . In returning back to step  100  the system  14  is performing as a feed-back system as to continuously regulate and adjust a clean fluid parameter, thereby maximizing efficiency for ever changing contamination levels. 
     The present invention provides an apparatus and method of separating particles in an induced fluid of an engine. The present invention allows for continuous fluid parameter adjustments as to provide fuel efficiency and minimize the amount of contamination entering a vehicle engine. In so doing, minimizing degradation of engine componentry and maximizing power and range of operation in various contamination leveled conditions. 
     The above-described apparatus, to one skilled in the art, is capable of being adapted for various purposes and is not limited to the following systems: automotive vehicle systems, control systems, aeronautical vehicle systems, or other applications requiring the separation of particles within a fluid. The above described invention may also be varied without deviating from the spirit and scope of the invention as contemplated by the following claims.