Devices for flow measurement

Abstract

1. A flow body unit (600) for a fluid flow rig (10) for simulating fluid flow patterns, the flow body unit (600) comprising: a flow body support frame (700); and a core member (800) extending from the flow body support frame (700) along a flow body unit longitudinal axis (630), the core member (800) having a leading edge (822) and a trailing edge (824), the core member (800) being attached to the flow body support frame (700) at its trailing edge (824) such that the core member (800) extends outwardly from the flow body support frame (700) to terminate at a free end (834) defined by the leading edge (822).

Description

[Technical Field]

[0001] The present disclosure relates to an apparatus for flow measurement.

[0002] In particular, the present disclosure relates to a rake assembly and / or components thereof for enabling measurement of fluid flow parameters within a fluid flow rig. [Background technology]

[0003] An intake rake is a device used, for example, as part of wind tunnel intake testing to provide measurements of flow parameters at the intake to an engine. The rake is a pressure measurement device placed on an engine face that is simulated in a scaled intake model.

[0004] Typically, a rake with a probe is fixed in place within the flow chamber. Therefore, measurements are typically made within a fixed location, and therefore, some of the flow is not measured. Increasing the number of rakes increases the number of locations where measurements can be made, but increases flow blockage and changes the flow characteristics. Traditionally, to reduce the effects of flow blockage, other features of the engine, such as the center flow bullet, are omitted from the model. However, this omission also adversely affects the flow pattern.

[0005] Any maintenance or adjustment to the rake or its attached probes requires significant disassembly and disturbance to the entire rake and associated instrumentation setup. After reassembly, extensive retesting is then required to ensure the entire rake system is properly restored and connected.

[0006] Because conventional rakes are all single-function (e.g., measuring distortion, performance, and swirl data), obtaining a full map of the flow characteristics of a region requires that different rakes be swapped in during testing, necessitating repeating the test conditions to obtain the desired measurements.

[0007] Therefore, a flow measurement device that allows greater versatility in the number, type, and location of rakes present, reduces the effects of flow blockage, and simplifies maintenance and configuration is highly desirable. Summary of the Invention

[0008] According to the present disclosure, there is provided an apparatus and method as set out in the accompanying claims. Other features of the invention will become apparent from the dependent claims and the following description.

[0009] Accordingly, a rake assembly (100) for measuring fluid flow parameters in a fluid flow rig (10), the rake assembly (100) comprising: a housing (102) having a wall (104) defining a flow path (110) having a flow inlet (112) and a flow outlet (114); the flow path (110) extending from the flow inlet (112) to the flow outlet (114), wherein the housing wall (104) defines an access opening (106), and the housing (102) is configured to define an aerodynamic instrument plane (AIP) at or partway downstream of the flow inlet (112); and an instrumentation device (106) extending from a leading edge (122) to a trailing edge (124) and configured to be removably attached to the housing (102). A rake assembly (100) may be provided, comprising an instrumentation arm (120) operable to extend through the access opening (106) when attached to the housing wall (104) such that the instrumentation arm (120) extends at least partway across the flow path (110), the access opening (106) and the instrumentation arm (120) being sized such that the instrumentation arm (120) can be removed from the casing wall (104) by withdrawing the instrumentation arm (120) from the access opening (106), and such that the instrumentation arm (120) can be installed on the casing wall (104) by inserting the instrumentation arm (120) through the access opening (106).

[0010] The housing (102) may be cylindrical and centered on a longitudinal axis (130).

[0011] The access opening (106) may be elongated and extend along the housing wall (104) in alignment with the longitudinal axis (130), with the access opening (106) spaced apart from the inlet (112) and outlet (114) ends of the housing (102).

[0012] The instrumentation arm (120) may have a mounting end (136) configured to be attached to the housing (102) and a free end (134) distal to the mounting end (136) that is located within the flow path (110) during use.

[0013] The instrumentation arm (120) may include a probe (200) having a free end (234) that defines a portion of a leading edge end (222) of the probe (200), the probe (200) extending from the leading edge end (222) to the trailing edge end (224), the leading edge end (222) of the probe (200) being located within the aerodynamic instrument plane (AIP).

[0014] The instrumentation arm (120) may include a plurality of probes (200), each having a free end (234) that defines a portion of the leading end (222) of the probe (200), and each probe (200) extends from the leading end (222) to the trailing end (224).

[0015] The instrumentation arm (120) may include a probe mounting body (202) extending from the instrumentation arm mounting body (132) between the mounting end (136) and the instrumentation arm free end (134), and the or each probe (200) extending from the probe mounting body (202).

[0016] The housing wall (104) may define a plurality of access openings (106) spaced around the circumference of the housing wall (104).

[0017] The rake assembly (100) may further include a plurality of instrumentation arms (120), each configured to fit within a different access opening (106) and to be installed and removed independently of the other instrumentation arms.

[0018] The rake assembly (100) may further include an instrumentation cable (240) and / or a tube (242) for coupling to the / each probe (200), wherein the outer surface (150) of the housing wall (104) includes a first recess (152) adjacent the access opening (106), the first recess (152) extending at least partway around the housing wall (104) and configured to position the instrumentation cable (240) and / or the tube (242).

[0019] The rake assembly (100) may include a plurality of instrumentation cables (240) and / or tubes (242) for coupling to its / each probe (200), wherein the first recess (152) is configured to position the instrumentation cables (240) and / or tubes (242).

[0020] The housing wall may further comprise a second recess (154) at the inlet (112) of the flow path (110); and an adapter intake ring (300) configured to fit within the second recess (154), the adapter intake ring (300) having an outer surface (302) for engaging the second recess (154) in the housing wall and an inner surface (304) defining a flow surface, the adapter intake ring (300) being further configured to fit into an intake nozzle (400), the inner surface (304) of the adapter intake ring (300) being disposed between a nozzle flow surface (404) from the nozzle (400) and the inner flow surface (116) of the housing wall (104).

[0021] The second recess (154) may extend from the flow inlet (112) end and terminate at the aerodynamic instrument plane (AIP).

[0022] Also disclosed is a rake assembly (100) for measuring fluid flow parameters in a fluid flow rig (10), the rake assembly (100) comprising: a rake assembly support frame (500); a housing (102) mounted on the rake assembly support frame (500), the housing (102) having a wall (104) defining a flow path (110) having a flow inlet (112) and a flow outlet (114), the flow path (110) extending from the flow inlet (112) to the flow outlet (114), wherein the housing (102) is cylindrical and centered on a longitudinal axis (130); and an instrumentation arm (140). A rake assembly (100) may be provided, comprising: an instrumentation arm (120) extending from a leading end (122) to a trailing end (124), the instrumentation arm (120) extending from a housing wall (104) to extend at least partway across the flowpath (110), the leading end (122) located in an aerodynamic instrument plane (AIP), the housing (102) being rotatably mounted to a rake assembly support frame (500) such that the housing (102) and the instrumentation arm (120) are operable to rotate at least partway about a longitudinal axis (130).

[0023] The housing (102) may include bearing lands (160) on an outer surface thereof for engaging the rake assembly support frame (500). The support assembly (500) may include a first bracket (502) and a second bracket (504) defining a support interface (506), the support interface (506) extending around the housing (102), the support interface (506) configured to rotatably support the bearing lands (160) of the housing (102) such that the bearing lands (160) are rotatable relative to the support interface (506).

[0024] The support interface (506) may include a rotatable bearing (508).

[0025] The support interface (506) may include a low friction surface (510) for direct contact with the bearing lands (160) of the housing (102).

[0026] The rake assembly (100) may further include an actuator (512) coupled to the housing (102) and operable to drive the housing (102) about the longitudinal axis (130).

[0027] The rake assembly (100) may further include a control system (514) configured to control the actuator (512) to control the rotational speed of the housing (102) and / or to control the angular position of the instrumentation arm (120).

[0028] The control system (514) may be configured to control the actuator (512) to drive the housing (102) about the longitudinal axis (130) at a constant angular velocity at least partway about the longitudinal axis (130).

[0029] The control system (514) may be configured to control the actuator (512) to drive the housing (102) about the longitudinal axis (130) between a first angular position (P1) and a second angular position (P2).

[0030] Also provided is a method of operating a rake assembly (100) for measuring fluid flow parameters in a fluid flow rig (10), the rake assembly (100) comprising: a rake assembly support frame (500); a housing (102) mounted on the rake assembly support frame (500); the housing (102) comprising a wall (104) defining a flow path (110) having a flow inlet (112) and a flow outlet (114), the flow path (110) extending from the flow inlet (112) to the flow outlet (114), wherein the housing (102) is cylindrical and centered on a longitudinal axis (130). an instrumentation arm (120), wherein the instrumentation arm (120) extends from the housing wall (104) so ​​as to extend at least partway across the flow path (110), the housing (102) being rotatably mounted to the rake assembly support frame (500) such that the housing (102) and the instrumentation arm (120) are operable to rotate at least partway about the longitudinal axis (130), a method of operating a rake assembly (100) may be provided, the method including rotating the housing (102) at least partway about the longitudinal axis (130).

[0031] The rake assembly (100) may further include an actuator (512) coupled to the housing (102) and operable to drive the housing (102) about the longitudinal axis (130), and a control system (514) configured to control the actuator (512) to control the rotational speed of the housing (102) and / or the angular position of the instrumentation arm (120), and the method comprises operating the control system (514) to control the actuator (512) to rotate the rake assembly support frame (500) at least partway about the longitudinal axis (130) between a first angular position (P1) and a second angular position (P2).

[0032] There may also be provided a method of operating a fluid flow rig (10) comprising a method of operating a rake assembly (100) according to the present disclosure, the method comprising the steps of positioning the housing (102), and therefore the instrumentation arm (120), in a first angular position (P1), delivering a fluid flow to an inlet of the housing (102), rotating the housing (102) at least partway around the longitudinal axis (130) so that the instrumentation arm (120) is in a second angular position (P2), and measuring characteristics of the fluid flow using the instrumentation arm (120) at the second angular position (P2).

[0033] The method of operating the fluid flow rig (10) may further comprise positioning the housing (102), and hence the instrumentation, with no fluid flow being delivered to the inlet of the housing (102).

[0034] The method of operating the fluid flow rig (10) may further comprise delivering a fluid flow to the inlet of the housing (102) while the housing (102) is rotated about the longitudinal axis (130).

[0035] Also provided may be a flow body unit (600) for a fluid flow rig (10) for simulating fluid flow patterns, the flow body unit (600) comprising a flow body support frame (700) and a core member (800) extending from the flow body support frame (700) along a flow body unit longitudinal axis (630), the core member (800) having a leading end (822) and a trailing end (824), the core member (800) being attached to the flow body support frame (700) at its trailing end (824) such that the core member (800) extends outwardly from the flow body support frame (700) to terminate at a free end (834) defined by the leading end (822).

[0036] In the direction from the core member leading edge (822) to the core member trailing edge (824), the core member (800) may comprise:

[0037] a first region (830) of the flow body that increases in diameter from a point at the core member leading edge (822) to a second region (832); the second region (832) extends toward the core member trailing edge (824) to a third region (834), the second region (832) increasing in diameter at a gradually decreasing rate with increasing distance from the core member leading edge (822); The third region (834) extends toward the core member trailing end (824) to a fourth region (836), the third region (834) decreasing in diameter with increasing distance from the core member leading end (822); the fourth region (836) extends toward the core member trailing end (824) to a fifth region (838), the fourth region (836) having a constant diameter with increasing distance from the core member leading end (822); the fifth region (838) extends toward the core member trailing end (824) to a sixth region (840), the fifth region (838) increasing in diameter at a gradually decreasing rate with increasing distance from the core member leading end (822); A sixth region (840) extends toward the core member trailing end (824), and the sixth region (840) decreases in diameter with increasing distance from the core member leading end (822).

[0038] The flow body support frame (700) may comprise a base member (710) configured to be attached to the housing (102), the base member (710) defining an opening (712) centered on the flow body unit longitudinal axis (630), and a core member (800) centered on and extending along the flow body unit longitudinal axis (630); and struts (714) extending from the base member (710) to the core member (800).

[0039] A plurality of struts (714) may extend from the base member (710) to the core member (800), the struts (714) being spaced apart from one another about the flow body unit longitudinal axis (630) to define flow paths (730) between the struts (714).

[0040] The / each strut (714) may comprise an airfoil profile (716).

[0041] Also disclosed is a rake assembly (100) for measuring fluid flow parameters within a fluid flow rig (10), the rake assembly (100) comprising: a housing (102) having a wall (104) defining a flow path (110) having a flow inlet (112) and a flow outlet (114), the flow path (110) extending from the flow inlet (112) to the flow outlet (114), wherein the housing wall (104) defines an access opening (106); an instrumentation arm (120) extending from a leading end (122) to a trailing end (124) and configured to be removably attached to the housing (102); A rake assembly (100) may be provided, further comprising a flow body unit (600) according to the present disclosure mounted to the housing (102) such that the flow body unit longitudinal axis (630) is aligned with the housing longitudinal axis (130) and such that the first region (830) of the core member (800) is disposed upstream of the leading end (122) of the instrumentation arm (120), the flow body unit comprising: an instrumentation arm (120) operable to extend through the access opening (106) such that the instrumentation arm (120) extends at least partway across the flow path (110) when mounted to the housing wall (104);

[0042] Thus, a flow measurement device is provided that allows greater versatility in the number, type, and location of existing rakes (i.e., instrumentation arms), reduces the effects of flow blockage, and simplifies maintenance and configuration.

[0043] Embodiments of the present invention will now be described, by way of example only, with reference to the figures, in which: [Brief explanation of the drawings]

[0044] [Figure 1] 1 illustrates a fluid flow rig including a rake assembly according to the present disclosure; [Figure 2] 10A-10C illustrate alternative examples of rake assemblies according to the present disclosure. [Figure 3] FIG. 2 shows the rake assembly of FIG. 1 with some components removed. [Figure 4] FIG. 3 shows the rake assembly of FIG. 2 with some additional components removed. [Figure 5] FIG. 2 is an exploded view of an example rake assembly of the present disclosure. [Figure 6] FIG. 1 is a cross-sectional view through the rake assembly. [Figure 7] FIG. 10 illustrates the rotation of the rake assembly. [Figure 8] Another view showing the rotation of the rake assembly. [Figure 9] 10 illustrates the mating of an instrumentation arm of a rake assembly according to the present disclosure; [Figure 10] FIG. 10 is another view illustrating the mating of the instrumentation arm of the rake assembly according to the present disclosure. [Figure 11] FIG. 10 is another view illustrating the mating of the instrumentation arm of the rake assembly according to the present disclosure. [Figure 12] FIG. 1 shows the mounting end of the instrumentation arm and associated instrumentation. [Figure 13] FIG. 10 is another view showing the mounting end of the instrumentation arm and associated instrumentation. [Figure 14] FIG. 10 is another view showing the mounting end of the instrumentation arm and associated instrumentation. [Figure 15] FIG. 10 is a further view of a portion of the rake assembly. [Figure 16] FIG. 10 is a further view of a portion of the rake assembly. [Figure 17] 1 illustrates an example of a rake assembly having a nozzle arrangement. [Figure 18] 10A-10C illustrate examples of rake assemblies having different nozzle arrangements. [Figure 19] 10A-10C illustrate examples of rake assemblies having different nozzle arrangements. [Figure 20] 10A-10C illustrate examples of rake assemblies having different nozzle arrangements. [Figure 21] 1 illustrates an example technical advantage of the present disclosure. [Figure 22] FIG. 10 is another diagram illustrating an example technical advantage of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0045] The present disclosure relates to a rake assembly 100 for measuring fluid flow parameters in a fluid flow rig 10. Typically, the fluid is air, but may also be a gas or a liquid, or a combination of the two.

[0046] Such a rake assembly 100 is used for testing intakes to an engine, such as an aircraft intake, to ensure that the flow pattern of the air entering the fan and compressor is acceptable for successful operation of the engine. This is often required because the intake is adjacent to a portion of the aircraft airframe or adjacent the end of the intake nozzle and therefore may be vulnerable to disruption.

[0047] Additionally or alternatively, such rake assemblies may be utilized in other applications where fluid flow characteristics within piping ducts and generators need to be understood, including inlets to naturally aspirated internal combustion engines, compressor systems such as turbo units and superchargers, steam power applications, hydroelectric power systems, air conditioning systems, heat pumps, and the like.

[0048] Therefore, a flow duct can be constructed that defines a flow path 110 with at least one region having the same shape as the engine intake. A rake assembly 100 according to the present disclosure may be located within a chamber within a region modeled above the engine intake. This region where measurements are taken is the aerodynamic instrument plane (AIP).

[0049] The flow duct may be made to scale but smaller than the actual engine intake. This is because a full-size wind tunnel is expensive to build, maintain, and operate. A smaller rig size is more practical. As a result, the flow passage 110 is smaller than the production version of the engine, which means that a rake assembly with instrumentation within the flow passage will have a greater impact on flow blockages and / or obstructions, there will be less space to accommodate the various probes required, and there will be fewer opportunities to access the interior spaces within the flow passage 110 to maintain or replace the probes.

[0050] Figure 1 shows an example of a fluid flow rig 10 including a rake assembly 100 of the present disclosure. Figures 2, 3, and 4 show an example of the rake assembly 100 with some features removed for clarity to allow illustration of other details as described below. Figure 5 shows an exploded view of the rake assembly 100. Figure 6 shows a partial cross-sectional side view of an example configuration of the rake assembly 100.

[0051] As shown in Figures 2, 3, and 4, the rake assembly 100 may include a housing 102 having a wall 104 that defines a flow path 110. The housing 102 is cylindrical and centered on a longitudinal axis 130. The housing 102 is configured to define an aerodynamic instrument plane AIP partway downstream from the flow inlet 112.

[0052] The engine aerodynamic instrument plane AIP is the datum for airflow measurements. At full scale (in a production aircraft), the engine AIP is typically defined as the interface between the inlet duct and the front of the engine assembly. Therefore, for consistency, this location is also respected in production development models, such as those used in wind tunnels.

[0053] In such wind tunnel models, the internal geometry of the inlet and inlet duct and exhaust are recreated to a scale that is compatible with the wind tunnel. The engine itself is usually not represented in these induction system tests; instead, a measurement device known as an engine surface rake takes its place between the inlet duct and the exhaust.

[0054] The instrumentation rake of the rake assembly presents an array of sampling devices on or near the AIP, but crucially in doing so must not impose a significant obstruction on the passing fluid flow as this may produce unrepresentative results.

[0055] The air inlet at the engine AIP of a typical axial jet engine is always circular, but due to the often convoluted route from the external intake to the internal engine, the shape of the duct immediately in front of the engine is not always cylindrical. For validation testing, it is essential to recreate such features as closely as possible in the scale model.

[0056] While the inlet of a full-scale engine casing is necessarily circular, the inlet duct preceding it is not always cylindrical. Furthermore, the duct exit, and therefore the duct exit flow, is typically not always aligned with the axis of the engine rake. This can easily lead to inconsistent data if the AIP is not placed near the rake interface in such cases.

[0057] The flow passage 110 defines a flow inlet 112 and a flow outlet 114, and the flow passage 110 extends from the flow inlet 112 to the flow outlet 114. The housing wall 104 defines at least one access opening .

[0058] As shown in FIG. 4, the access opening 106 is elongated and extends along the housing wall 104 in alignment with (i.e., parallel to) the longitudinal axis 130, and the access opening 106 is spaced apart from the inlet 112 and outlet 114 ends of the housing 102.

[0059] 5, 6, and 9-11, the rake assembly 100 may include an instrumentation (or rake) arm 120. As shown in FIGS. 9-11, the instrumentation arm 120 extends from a leading end 122 to a trailing end 124. The instrumentation arm 120 is configured to be removably attached to the wall 104 of the housing 102.

[0060] The instrumentation arm 120, when attached to the housing wall 104, is operable to extend through the access opening 106 such that the instrumentation (or rake) arm 120 extends at least partway across the flow path 110. The instrumentation (or rake) arm 120 may extend radially. The instrumentation arm 120 may extend 30% but not more than 50% across the flow path 110. The instrumentation arm 120 may extend all the way across the flow path 110.

[0061] 9-11 , the access opening 106 and the instrumentation arm 120 are sized and shaped (i.e., configured or arranged) such that the instrumentation arm 120 can be removed from the casing wall 104 by withdrawing the instrumentation arm 120 from the access opening 106. The access opening 106 and the instrumentation arm 120 are sized and shaped (i.e., configured or arranged) such that the instrumentation arm 120 can be removed from and / or inserted radially into the casing wall 104 (i.e., housing 102) by withdrawing the instrumentation arm 120 radially from the access opening 106. Thus, removal / insertion only requires translation of the instrumentation arm in a single dimension (e.g., perpendicular to the longitudinal axis 130), thereby providing inherent protection of the probe.

[0062] As shown in Figures 9-11, the access opening 106 and the instrumentation arm 120 are also sized and shaped so that the instrumentation arm 120 can be installed on the casing wall 104 by inserting the instrumentation arm 120 through the access opening 106.

[0063] Therefore, the access opening 106 has a cross-sectional shape that corresponds to the cross-sectional shape of the instrumentation arm 120. In other words, when the instrumentation arm 120 is mated to the housing 102, there may be an interference fit or small gap between the periphery of the instrumentation arm 120 and the edge of the access opening 106.

[0064] As shown in FIGS. 6 , 9 - 11 , the instrumentation arm 120 may include a mounting end 136 configured to be attached to the housing 102 and a free end 134 distal to the mounting end 136 that is located within the flow path 110 during use. As shown in FIGS. 12 - 14 , the mounting end 136 may be provided as a flange or plate 140 extending laterally outward from the instrumentation arm 120 such that when the instrumentation arm 120 is fitted within the access opening 106, the flange 140 covers the access opening 106, thereby preventing the instrumentation arm 120 from falling into the flow chamber. The flange 140 may be bolted to the housing 102, for example, via bolt holes provided in the flange and tappings in the housing 102. Thus, the instrumentation arm can be slid into and removed from the access opening 106.

[0065] The instrumentation arm 120 may include a probe 200 having a free end 234 that defines a portion of a leading end 222 of the probe 200 , the probe 200 extending from the leading end 222 to a trailing end 224 .

[0066] The leading edge 222 of the probe 200 may be located in the aerodynamic instrument plane AIP.

[0067] The instrumentation arm 120 may include a plurality of probes 200, each having a free end 234 that defines a portion of the leading edge end 222 of the probe 200, each probe 200 extending from the leading edge end 222 to the trailing edge end 224 and positioned within the aerodynamic instrument plane AIP.

[0068] The instrumentation arm 120 defines a probe mounting body 202. The probe mounting body 202 extends from the instrumentation arm mounting body 132 between the mounting end 136 and the instrumentation arm free end 134. The or each probe 200 extends from the probe mounting body 202. Thus, when installed within the housing 102, the or each probe 200 extends from the probe mounting body 202 toward the flow inlet 112 of the housing 102. Thus, the instrumentation arm 120 comprises the probe mounting body 202 and the or each probe 200.

[0069] In some examples, the housing wall 104 defines a plurality of access openings 106 spaced around the circumference of the housing wall 104. In some examples, a plurality of instrumentation arms 120 may be provided, each of which fits within a different access opening 106 and is configured to be installed and removed independently from the other instrumentation arms.

[0070] As shown in Figures 12-14, instrumentation cables 240 and / or tubing 242 may also be provided for coupling to the / each probe 200 (when required, depending on the nature of the probe). As shown in Figures 6, 9-11, the outer surface 150 of the housing wall 104 may include a first recess 152 adjacent the access opening 106, the first recess 152 extending at least partway around the housing wall 104 and configured to position the instrumentation cables 240 and / or tubing 242.

[0071] In some examples, multiple instrumentation cables 240 and / or tubes 242 may be provided for coupling to the / each probe 200. The first recess 152 may be configured to position each / all of the instrumentation cables 240 and / or tubes 242. Thus, the first recess 152 is the space in which the cables 240 and / or tubes 242 are located, with the walls of the recess acting as guides. In some examples, the recess 152 is open to allow easy access for maintenance.

[0072] As shown in FIGS. 3-6 , the housing wall 104 may further include a second recess 154 at the inlet 112 of the flow passage 110. The rake assembly 100 may further include an adapter intake ring 300 configured to fit within the second recess 154. The adapter intake ring 300 may have an outer surface 302 for engaging the second recess 154 in the housing wall and an inner surface 304 defining a flow surface. The adapter intake ring 300 is configured to fit within an intake nozzle 400 (as shown in FIGS. 17-20 ), with the inner surface 304 of the adapter intake ring 300 disposed between the nozzle flow surface 404 from the nozzle 400 and the inner flow surface 116 of the housing wall 104.

[0073] The second recess 154 may extend from the flow inlet 112 end and terminate slightly upstream of or at the aerodynamic instrument plane (AIP).

[0074] To support modularity, each instrumentation arm 120 must be equipped with a common interconnect, as shown in Figures 12, 13, and 14. This interface allows for quick and reliable connection of both the electrical 240 and pneumatic 242 components of the instrumentation arm 120. Connection (and disconnection) is configured to be possible with minimal disturbance to adjacent circuitry on the rake housing.

[0075] Importantly, this connection must be made within the smallest possible space envelope, ideally not exceeding the planform of the arm header (i.e., mounting body 132) as this will improve and facilitate interchangeability. Additionally, the height of the interconnection must be kept to a minimum as it will likely be positioned at and define the outermost perimeter of the rake assembly.

[0076] 12, 13, and 14, the pneumatic lines 242 are shown terminated in a simple stepped configuration to facilitate making individual sleeved connections while minimizing bulk volume. Electrical connections are made within microconnectors secured to the arm headers. To achieve the goal of modularity, any alternative connection solutions that may be utilized must also adhere to the basic space constraints outlined here.

[0077] A flexible interconnect is therefore located on the rake housing 102 relative to the location of each arm 120. Having such a nearby interconnection point or "plug break" negates the need to unwind the tubing and wiring routes from the bundle each time an arm is removed for maintenance.

[0078] In conventional rakes, associated wiring and pneumatic lines are typically routed around the rake, passing over the heads of adjacent arms. In the arrangement of the present disclosure, provision is made for wires 240 and tubes 242 by extrapolating the rear of the rake housing to create an annular gallery, in this case downstream of arm 120.

[0079] Thus, combined bundles of wires and tubes may be formed in a logical fashion so that they emerge from the rake in locations that fit the model as single (or multiple) umbilical cords, terminated at appropriate lengths by connecting media to suit the application.

[0080] The static pressure measurement location may be placed a sufficient distance from the rake arm and probe tip to reduce any upstream effects.

[0081] Therefore, the manner in which each instrumentation arm 120 is attached to the housing 102 allows them to be swapped in and out when needed without disturbing / removing another instrumentation arm 120 or having to dismantle the rig assembly. The addition of the recesses 152 also provides for secure packaging of associated wiring 240 and / or tubing 242 and routing them on the rake housing 102 within a given space envelope.

[0082] The mounts 132 are common to all instrumentation arms 120. Therefore, they can be fitted anywhere within the housing 102. They also allow translation in one single axis, which can be controlled along a single guide tool (e.g., a blue bolt) to minimize potential collisions that could expose the delicate calibrated probes to potential damage. Spare instrumentation arms 120 can be pre-assembled and swapped for any arm in any position. Additionally, they can be replaced blank (either stand-alone or as a complete set) or to include different instrumentation for measuring different physical properties. They can also have sufficient margin to be modified or refurbished to meet future requirements, such as different sensor configurations.

[0083] Additionally or alternatively, the rake assembly 100 may include a rake assembly support frame 500, as shown in FIGS. 3-6. The housing 102 may be rotatably mounted to the rake assembly support frame 500 such that the housing 102 and instrumentation arm 120 are operable to rotate at least partway about the longitudinal axis 130, as shown in FIGS. 7 and 8. This may be configured to allow 360 degrees of free mechanical rotation to support fault finding or alternate / future unknown model configurations. Once assembled and tubing / routing installed, rotation is limited.

[0084] The support frame 500 includes a first bracket 502 and a second bracket 504 that define a support interface 506 that extends around the housing 102. The housing 102 may include a bearing land 160 on an outer surface thereof for engaging the rake assembly support frame 500. The support interface 506 may be configured to rotatably support the bearing land 160 such that the bearing land 160 of the housing 102 is rotatable relative to the support interface 506.

[0085] The brackets 502, 504 form clamp halves that each extend around a portion of the circumference of the housing 102. For example, the brackets 502, 504 each extend halfway around the housing 102 so that when the brackets 502, 504 are joined together, the bracket assembly 500 restrains the housing 102 to support the housing 102 around its entire circumference. Locking means may also be provided to secure the housing 102 in place. The locking means may comprise a dowel that extends through at least one of the brackets 502, 504 and into an opening in the surface of the housing 102. However, any suitable locking means for securing the angular position of the housing 102 about the longitudinal axis 130 may be used. The locking means may be manually operated by a user (i.e., not mechanized). The locking means may be remotely actuated so that the housing can be rotated about the longitudinal axis 130 without the user having to manually remove and install the locking means in a different angular position.

[0086] The support interface 506 may include a rotatable bearing 508. That is, the brackets 502, 504 may include a rotatable bearing that supports the housing 102, or the rotatable bearing 508 is provided between the brackets 502, 504 and the housing 102. Additionally or alternatively, the support interface 506 may include a low-friction member 510 (providing a low-friction surface) for direct contact with the bearing lands 160 of the housing 102. As shown in FIG. 6 , the low-friction member 510 may be located between the rotatable bearing 508 and the housing 102. In other examples, if a rotatable bearing is not present, the low-friction member may be provided between the brackets 502, 504 and the housing 102.

[0087] As shown in FIG. 2, the rake assembly 100 may further include an actuator 512 coupled to the housing 102 and operable to drive the housing 102 about the longitudinal axis 130 .

[0088] The actuator 512 may include a rotatable gear 518 driven by a motor, which is engaged with a gear surface on the housing 102 such that the actuator 512 may drive the housing 102 about the longitudinal axis 130. The actuator may be drivingly re-engaged with the housing 102 in any suitable manner; for example, instead of a gear, a belt drive may be provided, or a wheel driven by a motor from the actuator 512 is frictionally engaged with the housing 102.

[0089] As shown in FIG. 2, the rake assembly 100 may further include a control system 514 configured to control the actuator 512 to control the rotational speed of the housing 102 and / or to control the angular position of the instrumentation arm 120.

[0090] The control system 514 is configured to control the actuator 512 to drive the housing 102 about the longitudinal axis 130 at a constant angular velocity at least partway about the longitudinal axis 130 .

[0091] The control system 514 may be configured to control the actuator 512 to drive the housing 102 about the longitudinal axis 130 between a first angular position (P1) and a second angular position (P2).

[0092] 7 and 8, in use, the actuator 512 may be operated to rotate the housing 102 at least partway about the longitudinal axis 130. That is, the actuator 512 may be operated to rotate the housing 102 all the way around the longitudinal axis 130 (i.e., complete a full rotation).

[0093] Alternatively or additionally, the actuator 512 may be operated to rotate the housing 102 less than all the way about the longitudinal axis 130. Thus, in use, the control system 514 may be operated to control the actuator 512 to rotate the rake assembly support frame 500 at least part way about the longitudinal axis 130 between the first angular position P1 and the second angular position P2.

[0094] 7 shows an end view of the housing 102 with the instrumentation arm 120 at the 12, 3, 6, and 9 o'clock positions, which may be defined as the first angular position P1.

[0095] 8 shows the same arrangement as shown in FIG. 7, but with housing 102 rotated clockwise such that instrumentation arm 120 is translated about longitudinal axis 130. This may be defined as a second angular position P2.

[0096] The second angular position P2 can be such that (as shown in the example of FIG. 8) the instrumentation arms 120 are halfway between the original positions of adjacent instrumentation arms 120. In this way, measurements can be made around the entire circumference of the flow area defined by the flow channel 110 without having to rotate the rake / instrumentation arms 120 around the entire circumference.

[0097] In use, the rake assembly may be operated such that while a fluid flow is being delivered to the inlet of the housing 102 or when no fluid flow is being delivered to the inlet of the housing 102, the control system 514 is operated to control the actuator 512 to place the housing 102, and therefore the instrumentation arm 120, at a first angular position P1. That is, the rake assembly may be operated such that while a fluid flow is being delivered to the inlet of the housing 102 or when no fluid flow is being delivered to the inlet of the housing 102, the control system 514 may be operated to control the actuator 512 to rotate the housing 102 at least partway about the longitudinal axis 130 such that the instrumentation arm 120 is moved from the first angular position P1 to a second angular position P2 such that characteristics of the fluid flow may be measured using the instrumentation arm 120 at the second angular position P2.

[0098] In use, the rake assembly may be operated such that while a fluid flow is being delivered to the inlet of the housing 102 or when no fluid flow is being delivered to the inlet of the housing 102, the control system 514 is operated to control the actuator 512 to position the housing 102, and therefore the instrumentation arm 120, at a first angular position (P1), and then, when a fluid flow is being delivered to the inlet of the housing 102, the control system 514 is operated to control the actuator 512 to rotate the housing 102 at least partway around the longitudinal axis 130 such that the instrumentation arm 120 is moved from the first angular position P1 to a second angular position (P2) so that characteristics of the fluid flow can be measured using the instrumentation arm 120 at the second angular position (P2).

[0099] The method of operation may further comprise disposing the housing 102, and therefore the instrumentation, with no fluid flow being delivered to the inlet of the housing 102.

[0100] The method of operation may comprise delivering a fluid flow to an inlet of the housing 102 while the housing 102 is rotated about the longitudinal axis 130 .

[0101] Therefore, by providing a rotatable housing 102 for moving the instrumentation arms 120 about the longitudinal axis, planar measurements of the entire engine surface are enabled. This may be automated in the future to allow the rake arms to adjust their angular position during operation. This also has the advantage that entire engine phase planar measurements can be achieved using a relatively small number of instrumentation arms 120, thus reducing overall flow blockage / obstruction within the flowpath 110.

[0102] By mechanizing the rotation of the housing, multiple (even infinite) set points (i.e., angular positions) can be commanded without manual intervention. Thus, multiple set points can then be reported in a very short time, dramatically reducing the cost of testing.

[0103] Additionally or alternatively, a flow body unit (or "bullet") 600 may be provided, configured to mate with the housing 102 to become part of the rake assembly 100. The flow body unit 600 is shown in FIGS. 3, 5, and 6. The flow body unit 600 may include a flow body support frame 700 for mounting to the fluid flow rig 10 and holding the flow body unit 600 in a fixed position relative to the housing 102 of the fluid flow rig 10. The flow body unit 600 may also include a core member 800 extending from the flow body support frame 700 along the longitudinal axis 630 of the flow body unit. The core member 800 may have a leading end 822 and a trailing end 824. The core member 800 may be attached to the flow body support frame 700 at its trailing end 824 such that it extends outwardly from the flow body support frame 700 to terminate at a free end 834 defined by the leading end 822. The core body 800 may be removable from the body support frame 700. The core body 800 and the body support frame 700 may be configured such that the core body 800 is removable from the body support frame 700 without having to interfere with the rake arms 120. For example, the core body 800 may be removed from the body support frame 700 by moving it relative to the body support frame 700 along the longitudinal axis 130. Similarly, a replacement core body 800 (of the same or a different shape) may be attached to the body support frame 700 without having to interfere with the rake arms 120.

[0104] In a direction along the flow body unit longitudinal axis 630 from the core member leading end 822 toward the core member trailing end 824, and as best shown in FIG. 6 , the flow body first region 830 increases in diameter from a point at the core member leading end 822 to a second region 832. The first region 830 may be conical or may change in diameter at a constant rate. The first region 830 may also change in diameter at a variable rate (e.g., be curved).

[0105] Second region 832 may extend toward core member trailing end 824 to a third region 834, with second region 832 increasing in diameter at a gradually decreasing rate with increasing distance from core member leading end 822. The point where second region 832 meets third region 834 may define a bend.

[0106] The third region 834 may extend toward the core member trailing end 824 to a fourth region 836 , with the third region 834 decreasing in diameter with increasing distance from the core member leading end 822 .

[0107] The fourth region 836 may extend toward the core member trailing end 824 to a fifth region 838, with the fourth region 836 having a constant diameter as the distance from the core member leading end 822 increases.

[0108] The fifth region 838 may extend toward the core member trailing edge 824 to a sixth region 840, with the fifth region 838 increasing in diameter at a gradually decreasing rate as the distance from the core member leading edge 822 increases.

[0109] The sixth region 840 may extend toward and terminate at the core member trailing edge 824, with the sixth region 840 decreasing in diameter with increasing distance from the core member leading edge 822.

[0110] The flow body support frame 700 may include a base member 710 configured to be attached to the housing 102. The base member 710 may define an opening 712 centered on the flow body unit longitudinal axis 630. The core member 800 may be centered on and extend along the flow body unit longitudinal axis 630. Struts 714 may extend from the base member 710 to the core member 800. The struts 714 may extend from a sixth region 840.

[0111] A plurality of struts 714 may extend from the base member 710 to the core member 800. Each strut 714 may extend from the sixth region 840. The struts 714 may be spaced apart from one another about the flow body unit longitudinal axis 630 to define flow paths 730 between the struts 714.

[0112] The / each strut 714 may include an airfoil profile 716. The / each strut 714 may define a profile that is shaped to minimize upstream effects.

[0113] The flow body unit 600 may be mounted to the housing 102 such that the longitudinal axis 630 of the flow body unit 600 is aligned with the longitudinal axis 130 of the housing 102 .

[0114] The flow body unit 600 may be mounted to the housing 102 such that the first region 830 of the core member 800 is disposed upstream of the leading end 122 of the instrumentation arm 120 .

[0115] 21 and 22 illustrate the advantages of the shape of the flow body unit 600. In these figures, fluid flow is from right to left. FIG. 21 illustrates a flow body unit design not in accordance with the present disclosure. FIG. 22 illustrates a flow body unit 600 similar to that of the present disclosure, with some differences. However, as can be seen in the figures, the shape of the flow body unit 600 downstream of the first region 830, particularly the second region 832, has a significant impact on the flow area within this region. Therefore, as can be seen in FIG. 21, the flow area downstream of the first region 830 is larger than in the design in accordance with the present disclosure of FIG. 22.

[0116] Therefore, the shape of the flow body unit 600, ie, the variations in diameter of the different regions 830, 832, 834, 836, 838, 840, contributes to reducing flow blockage in the rig assembly 100.

[0117] The first region 830 of the flow body unit 600 is configured to represent as closely as possible the intake bullets on the engine.

[0118] Blockage (i.e., reduction of free area relative to the measurement plane area) is one of the biggest challenges faced in rake design. Increasing the rake diameter to maximize the free area is a key method in reducing blockage.

[0119] The placement of the first region 830 and the second region 832 relative to the measurement plane is also important. If the beginning of the branch in the first region 830 is located near the static pressure measurement plane, this can cause local flow accelerations that significantly affect the static pressure measurement. If the beginning of the branch is located too far aft / downstream, the branch angle will be too severe, causing flow separation around the wall, or maximum blockage will occur before the maximum branch diameter, either of which will severely increase blockage.

[0120] If the angle of branching becomes too large, the flow will move away from the wall and the effective area will be smaller than it actually is (as shown, for example, in Figure 21), causing the bullet to terminate prematurely.

[0121] By incorporating a mixing section (e.g., a bend where different regions meet) as shown in Figure 22, the increase in geometric area becomes more gradual and the effective area for the flow to remain attached also increases, helping to reduce blockage.

[0122] Therefore, each of the design features, i.e., the removable rotation arm 120, the rotatable housing for moving the dissertation arm 120 on the longitudinal axis 130, and the flow body unit 600, allows for greater versatility in the number, type, and location of rakes (i.e., instrumentation arms) present, reduces the effects of flow blockage, and simplifies maintenance and configuration of the flow rig.

[0123] The disclosed rake assembly 100 offers greater versatility in the number, type, and location of rakes (and therefore measurement locations), reduces the effects of flow blockage, and simplifies maintenance and configuration. Thus, the disclosed apparatus and instrumentation each contribute to achieving fluid flow through the rake assembly that is more representative of the simulated flow conditions than examples in the related art, while also reducing the time, expense, and resources required to do so.

[0124] The features of the rake assembly, singly and in combination, provide technical advantages. For example, the rake assembly 100 may include an instrumentation arm 120 that can be removed from the casing wall 104 by withdrawing the instrumentation arm 120 through the access opening 106. Alternatively or additionally, the housing 102 of the rake assembly 100 that carries the instrumentation arm may be rotatably mounted such that the housing 102 and the instrumentation arm 120 are operable to rotate at least partway about the longitudinal axis 130. Alternatively or additionally, the rake assembly 100 may include a flow body unit 600 configured to control the airflow path through the rig, reducing flow blockage within the rake assembly 100.

[0125] Although the disclosed apparatus and methods relate to rigs that are smaller in size than the full-size equipment they model, these rigs may be applied to full-size configurations as well, i.e., the disclosed apparatus and methods may be incorporated into full-size development rigs and / or production engines.

[0126] Attention is directed to all documents and literature related to this application, filed contemporaneously with or prior to this application, and hereby made available to the public, and the contents of all such documents and literature are incorporated herein by reference.

[0127] All of the features disclosed within this specification (including all accompanying claims, abstracts, and figures), and / or all of the steps of any method or process so disclosed, may be combined in any combination, unless at least some of such features and / or steps are mutually exclusive combinations.

[0128] Each feature disclosed in this specification (including all accompanying claims, abstracts, and figures), unless expressly stated otherwise, may be replaced by alternative features serving the same, equivalent, or similar purpose. Thus, unless expressly stated otherwise, each feature disclosed is only one example of a generic series of equivalent or similar features.

[0129] The invention is not limited to the details of the foregoing embodiments, and extends to any novel one or any novel combination of features disclosed herein (including all accompanying claims, abstracts and drawings), or to any novel one or any novel combination of steps of any method or process so disclosed.

Claims

1. 1. A flow body unit for a fluid flow rig for simulating a fluid flow pattern, said flow body unit comprising: a flow body support frame; a core member extending from the flow body support frame along the flow body unit longitudinal axis; Equipped with a flow body unit, wherein the core member has a leading end and a trailing end, the core member being attached to the flow body support frame at the trailing end such that the core member extends away from the flow body support frame and terminates at a free end defined by the leading end.

2. From the leading edge of the core member toward the trailing edge of the core member, a first region of the flow body increasing in diameter from a point at the leading end of the core member to a second region; the second region extends toward the trailing end of the core member to a third region, the second region increasing in diameter at a gradually decreasing rate with increasing distance from the leading end of the core member; the third region extends toward the trailing end of the core member to a fourth region, the third region decreasing in diameter with increasing distance from the leading end of the core member; the fourth region extends toward the trailing end of the core member to a fifth region, the fourth region having a constant diameter with increasing distance from the leading end of the core member; the fifth region extends toward the trailing end of the core member to a sixth region, the fifth region increasing in diameter at a gradually decreasing rate with increasing distance from the leading end of the core member; 2. The flow body unit of claim 1, wherein the sixth region extends toward the trailing end of the core member, the sixth region decreasing in diameter with increasing distance from the leading end of the core member.

3. The flow body support frame is a base member configured to be attached to a housing, wherein the base member defines an opening centered on the flow body unit longitudinal axis, and the core member is centered on and extends along the flow body unit longitudinal axis; a strut extending from the base member to the core member; The flow body unit according to claim 1 or 2, comprising:

4. a plurality of struts extending from the base member to the core member; The flow body unit of claim 3 , wherein a plurality of the struts are spaced apart from one another about the flow body unit longitudinal axis to define flow paths between the struts.

5. 5. A flow body unit according to claim 3 or 4, wherein the or each strut comprises an airfoil profile.

6. 1. A rake assembly for measuring fluid flow parameters in a fluid flow rig, the rake assembly comprising: a housing having a wall defining a flow path having a flow inlet and a flow outlet, the flow path extending from the flow inlet to the flow outlet, the housing wall defining an access opening; an instrumentation arm extending from a leading end to a trailing end and configured to be removably attached to the housing; Equipped with the instrumentation arm is operable, when attached to the housing wall, to extend through the access opening such that the instrumentation arm extends at least part way across the flow path; The rake assembly includes: so that the flow body unit longitudinal axis is aligned with the housing longitudinal axis; and 6. A rake assembly further comprising a flow body unit according to claim 1, mounted to the housing such that a first region of the core member is provided upstream of the leading end of the instrumentation arm.

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