A mixing device for combined power high-altitude simulation test

Abstract

The present invention provides a mixing device for combined power high-altitude simulation testing, which is arranged inside a plenum chamber. The mixing device includes multiple nozzles, a front baffle and a rear baffle arranged at both ends of the nozzle, the front baffle and the rear baffle being connected to the cylinder support via a support seat, and a three-layer heat insulation plate provided inside the nozzle. The nozzle is slidably connected to the front baffle and fixedly connected to the rear baffle. The mixing device provided by the present invention is arranged inside the plenum chamber, eliminating the air supply pipeline from the outlet of the mixing device to the plenum chamber section in the traditional solution, greatly reducing the thermal inertia of the temperature control system of the air intake equipment, reducing the temperature loss caused by the development of the air flow along the process and the heat exchange of the pipe wall, shortening the time required to obtain the temperature conditions required for the test state through mixing, and improving the efficiency of entering the test state.

Description

Technical Field

[0001] The invention belongs to the technical field of high-altitude simulation tests of aviation engines, and in particular relates to a mixing device for combined power high-altitude simulation tests. Background Art

[0002] When conducting combined power high-altitude simulation tests, especially the verification of modal conversion technology, the process of the engine starting from the turbine stage to reach the modal conversion test point, and then switching to the ramjet stage and working for a specified time is a continuous and rapid change process. This requires the test air intake equipment to have the ability to quickly adjust the temperature to quickly respond to the rapid change of the simulated Mach number. At the same time, the requirements for the engine inlet flow field in GJB4879 are: the unevenness of the pressure field and temperature field shall not exceed ±1.0%, and the turbulence shall not exceed ±1.0%.

[0003] In the design and construction schemes of high-altitude simulation test equipment currently under construction or in use at home and abroad, the structure of the mixing device is a layered baffle type or a built-in tubular open-hole component. Two or even more air flows with different temperatures enter the mixing device and are mixed by diversion or forced heat exchange. The disadvantages of the traditional scheme are that the convective heat transfer efficiency is not high, and the limited internal space is not conducive to equipment maintenance; at the same time, for the intake equipment that meets the intake requirements of the engine test (total temperature and total pressure), the mixing device is set at the front end of the air supply network, and an axially long air supply pipeline is arranged between the outlet of the mixing device and the inlet of the stabilizing chamber to meet the needs of full development of the incoming flow (including the flow boundary layer, temperature boundary layer and mutual transition of flow state, etc.), and then the supply air flow enters the stabilizing chamber for deceleration and expansion, and is rectified by the rectifier (rectifier and wire mesh). The purpose of reducing the unevenness and turbulence of the flow field is achieved by breaking up the flow. At the same time, the pressure and temperature of the incoming flow are adjusted so that after meeting the test incoming flow conditions, the turbulence is further reduced through the contraction effect of the contraction device to enter the flow tube and be supplied to the test engine. Therefore, the traditional high-altitude simulation test intake equipment has a large temperature loss of the incoming air from the outlet of the mixing device to the entire flow section of the engine inlet due to multiple factors such as the development of the temperature boundary layer generated by the air flow and the sufficient heat exchange along the pipe wall. Although the requirements of the engine inlet flow field can meet the national military standards, in order to achieve the temperature conditions required by the test state point, it is necessary to wait for a long time for the heat exchange process of the intake equipment to reach equilibrium before entering the test state. Therefore, such a traditional design scheme cannot meet the test requirements of the modal conversion process for rapid temperature rise in the combined power high-altitude simulation test.

[0004] The current design and construction status of the mixing device in use is temporarily unable to meet the test requirements of the modal conversion function test of the combined power high-altitude simulation test for rapid adjustment of the intake temperature due to reasons such as large thermal inertia, high temperature loss along the flow, long heating time, and low test efficiency, which is not conducive to the smooth implementation of such tests. Summary of the Invention

[0005] In order to solve the above problems, the purpose of the present invention is to provide a technical solution for a fast heating mixing device for a combined power high-altitude simulation test modal conversion function test, so as to solve the problems of large thermal inertia, high temperature loss, long heating time and low test efficiency in the construction status of existing test equipment, and ensure the smooth implementation of the combined power high-altitude simulation test modal conversion function test.

[0006] In order to achieve the above-mentioned purpose, the present invention provides the following technical solutions, providing a mixing device for combined power high-altitude simulation test, wherein the mixing device is arranged inside a pressure stabilizing chamber, and the mixing device includes multiple nozzles, a front baffle and a rear baffle arranged at both ends of the nozzle, the front baffle and the rear baffle are connected to the cylinder support through a support seat, and three layers of heat insulation plates are provided in the nozzle, and the nozzle is slidably connected to the front baffle and fixedly connected to the rear baffle at the same time.

[0007] The mixing device for combined power high-altitude simulation test provided by the present invention also has the following characteristics: the sum of the total equivalent areas of the nozzles is the same as the flow area of the main air supply pipeline, and the sum of the equivalent areas of the staggered small holes in each nozzle is the same as the flow area of the high-temperature airflow. The high-temperature hot airflow enters the nozzle through the small holes and mixes with the main air supply mixing airflow in the nozzle.

[0008] The combined power high-altitude simulation test mixing device provided by the present invention also has the following characteristics: the support seat is arranged at the waist of the mixing device, there are multiple support seats, and expansion space is reserved between the front baffle and the cylinder.

[0009] The combined power high-altitude simulation test mixing device provided by the present invention also has the characteristic that eight support seats are evenly arranged at upstream and downstream positions of the front baffle and the rear baffle respectively.

[0010] The combined power high-altitude simulation test mixing device provided by the present invention also has the characteristic that the front baffle and the cylinder are sealed by a C-shaped gasket.

[0011] The mixing device for combined power high-altitude simulation test provided by the present invention also has the following characteristics: a first threaded seat is fixed on the front baffle, and the nozzle is fixed to the front baffle through a first threaded plug, a first threaded seat and a first limit block. The first threaded plug and the first threaded seat are locked by a round nut. A metal circular gasket and a C-shaped gasket for sealing are provided between the first threaded plug and the first threaded seat. The first threaded plug presses the metal circular gasket and the C-shaped gasket to achieve a sealing effect.

[0012] The mixing device for combined power high-altitude simulation test provided by the present invention also has the following characteristics: the surfaces of the connection area between the nozzle and the front baffle and the C-shaped gasket are finely processed to achieve a matching seal.

[0013] The mixing device for combined power high-altitude simulation test provided by the present invention also has the following characteristics: a transition seat is fixed downstream of the nozzle, and the nozzle is fixed to the rear baffle through a second threaded seat, a second threaded plug and a transition seat. The second threaded plug presses the transition seat onto the second threaded seat, and a metal sealing gasket is provided on the pressing surface for sealing. The second threaded seat and the second threaded plug are respectively fixed with a second limit block that fits tightly to prevent loosening, and the overlap length of the second limit block fixed on the second threaded seat and the second limit block fixed on the second threaded plug is not less than 10 mm.

[0014] The mixing device for combined power high-altitude simulation test provided by the present invention also has the following characteristics: the nozzle is made of a whole pipe, the upstream port of the nozzle is provided with a guide groove, the first limit block is arranged in the guide groove, and the first limit block is welded and fixed to the first threaded plug.

[0015] The mixing device for combined power high-altitude simulation test provided by the present invention also has the characteristic that the parallelism deviation between the center line of the nozzle and the connecting line of the center lines of the front baffle and the rear baffle is no more than 1 mm.

[0016] The mixing device for combined power high-altitude simulation test provided by the present invention also has the following characteristics: a front outer cover of a front heat insulation plate and an annular outer cover of a heat insulation plate are provided upstream of the nozzle; the front outer cover of the front heat insulation plate is supported and fixed by the front outer cover of the front heat insulation plate; a sealing ring supported and fixed by a sealing ring is provided between the nozzle and the cylinder.

[0017] Beneficial effects

[0018] 1) The mixing device provided by the present invention is arranged inside the stabilizing chamber, eliminating the air supply pipeline from the outlet of the mixing device to the stabilizing chamber section in the traditional solution, greatly reducing the thermal inertia of the temperature control system of the air intake equipment, reducing the temperature loss caused by the development of the air flow along the process and the heat exchange of the pipe wall, shortening the time to obtain the temperature conditions required for the test state through mixing, and improving the efficiency of entering the test state.

[0019] 2) Compared with the traditional mixing principle, the nozzle of the mixing device proposed in the present invention actually acts as a flow equalizer. The mixing principle is that the low-temperature mixed gas enters the nozzle of the mixing device through the main air supply pipeline, and the high-temperature supply air enters the nozzle through a small hole in the nozzle. The two airflows of different temperatures are mixed in a single nozzle, and all mixed flows are subjected to secondary mixing through expansion and deceleration in the rear baffle outlet area. This not only changes the mixing mechanism of the natural flow development of the air supply flow in the long-distance air supply pipeline in the traditional scheme from the perspective of mixing principle, but also strengthens the heat exchange process in space, effectively improving the mixing efficiency, and thus can meet the test conditions of rapid heating over a short distance.

[0020] 3) When the nozzle-type mixing device proposed in the present invention is in operation, the low-temperature airflow and the high-temperature airflow enter the nozzle through different areas, achieving the purpose of initial rectification, flow fragmentation and equalization of the airflow, and effectively reducing the turbulence of the incoming flow. The flow field is further uniformed by traditional rectification and contraction devices, and the engine inlet flow field quality can be achieved in a short and fast distance to meet the national military standard requirements for total temperature, total pressure and turbulence of ±1.0%.

[0021] 4) Compared with the traditional mixing device structure, the mixing device structure proposed in the present invention is a split-pipe type. If equipment maintenance is required during operation, it is only necessary to cut the spot weld between the nozzle and the transition seat at the rear baffle, and then pull out the single nozzle for maintenance or worse, which greatly improves the maintainability of the equipment. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the technical solutions of the embodiments of the present disclosure, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present disclosure. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0023] Figure 1 A schematic structural diagram of a mixing device provided in an embodiment of the present invention;

[0024] Figure 2 for Figure 1 Sectional view of the AA plane;

[0025] Figure 3 for Figure 1 A partial enlarged view of the front baffle and nozzle sealing structure in the mixing device indicated at position Ⅰ;

[0026] Figure 4 for Figure 2 A partial enlarged view of the limiting structure in the mixing device indicated at position II;

[0027] Figure 5 for Figure 1 A partial enlarged view of the rear baffle and nozzle sealing structure in the mixing device indicated at position III;

[0028] Figure 6 This is a schematic structural diagram of a nozzle in a mixing device provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0029] The present invention is further described in detail below with reference to the accompanying drawings and examples. However, it should be noted that these embodiments are not limitations of the present invention, and any equivalent transformations or substitutions in functions, methods, or structures made by ordinary technicians in this field based on these embodiments are within the scope of protection of the present invention.

[0030] In the description of the embodiments of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside" and "outside" and the like to indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the invention.

[0031] Furthermore, the terms "first," "second," "third," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of the technical features being referred to. Thus, a feature identified with "first," "second," etc., may explicitly or implicitly include one or more of such features. In the description of the present invention, unless otherwise specified, "plurality" means two or more.

[0032] The terms "mounted," "connected," and "connected" should be understood broadly. For example, they can refer to fixed, detachable, or integral connections; mechanical or electrical connections; direct or indirect connections through an intermediary; and internal communication between two components. Those skilled in the art will understand the specific meanings of these terms in the present invention based on specific circumstances.

[0033] like Figure 1-6 As shown, an embodiment of the present invention provides a mixing device for combined power high-altitude simulation testing. The mixing device is disposed within a plenum chamber and includes multiple nozzles 3, a front baffle 5, and a rear baffle 8 disposed at each end of the nozzles 3. The front baffle 5 and the rear baffle 8 are connected to the barrel support via a support seat. Three layers of thermal insulation plates are provided within the nozzles 3. The nozzles 3 are slidably connected to the front baffle 5 and fixedly connected to the rear baffle 8. The three thermal insulation plates are a first thermal insulation plate 9, a second thermal insulation plate 10, and a third thermal insulation plate 11. The sliding connection between the nozzles 3 and the front baffle 5 allows for the nozzles to freely release any axial displacement difference between the two baffles.

[0034] In some embodiments, the sum of the total equivalent areas of the nozzles 3 is the same as the flow area of the main air supply pipeline, and the sum of the equivalent areas of the staggered small holes in each nozzle 3 is the same as the flow area of the high-temperature airflow. The high-temperature hot airflow enters the nozzle 3 through the small holes and mixes with the main air supply mixed airflow in the nozzle.

[0035] In some embodiments, a support seat is positioned at the waist of the mixing device. Multiple support seats are provided, and expansion space is reserved between the front baffle 5 and the barrel. Flow field and structural analysis indicate that the baffle heats up faster than the barrel, and the reserved gap allows for free expansion of the front baffle 5.

[0036] In some embodiments, eight support seats are evenly arranged at upstream and downstream positions of the front baffle 5 and the rear baffle 8. The support seats are used to withstand the axial force generated by the pressure difference on both sides of the baffle.

[0037] In some embodiments, the front baffle 5 and the cylinder are sealed by a C-shaped gasket 15 .

[0038] In some embodiments, a first threaded seat 12 is fixed to the front baffle 5, and the nozzle 3 is fixed to the front baffle 5 through a first threaded plug 13, a first threaded seat 12 and a first limit block 17. The first threaded plug 13 and the first threaded seat 12 are locked by a round nut 16. A metal circular gasket 14 and a C-shaped gasket 15 for sealing are provided between the first threaded plug 13 and the first threaded seat 12. The first threaded plug 13 presses the metal circular gasket 14 and the C-shaped gasket 15 to achieve a sealing effect.

[0039] In some embodiments, the surfaces of the connection areas between the nozzle 3, the front baffle 5 and the C-shaped gasket 15 are finely machined to achieve a tight fit.

[0040] In some embodiments, a transition seat 21 is fixed downstream of the nozzle 3, and the nozzle 3 is fixed to the rear baffle 8 through a second threaded seat 19, a second threaded plug 20 and the transition seat 21. The second threaded plug 20 presses the transition seat 21 onto the second threaded seat 19, and a metal sealing gasket 18 is provided on the pressing surface for sealing. The second threaded seat 19 and the second threaded plug 20 are respectively fixed with a second limit block 22 that fits tightly to prevent loosening. The overlap length of the second limit block 22 fixed on the second threaded seat 19 and the second limit block 22 fixed on the second threaded plug 20 is not less than 10 mm.

[0041] In some embodiments, the nozzle 3 is machined from a single piece of tubing. A guide groove is provided at the upstream end of the nozzle 3. A first stopper 17 is disposed within the guide groove. The first stopper 17 is welded to the first threaded plug 13. After the first threaded plug 13 is locked into place with a round nut 16, the first stopper 17 is inserted into the nozzle guide groove. After positioning, the first stopper 17 is welded to the first threaded plug 13. During operation, the first stopper 17 provides guidance and support.

[0042] In some embodiments, the parallelism deviation between the center line of the nozzle 3 and the connecting line of the center lines of the front and rear baffles is no more than 1 mm.

[0043] In some embodiments, a front heat insulation plate front outer cover 2 and a heat insulation plate annular outer cover 4 are further provided upstream of the nozzle 3. The front heat insulation plate front outer cover 2 is fixed by the front heat insulation plate front outer cover 1. A sealing ring 6 fixed by a sealing ring support 7 is provided between the nozzle 3 and the barrel.

[0044] The assembly process of the mixing device provided in the above embodiment is as follows:

[0045] 1) All materials are made of materials that can withstand the combined power of the test subject to carry out the test requirements under all working conditions of the high-altitude simulation test. In order to meet the test requirements of a certain model, the plates, pipes and fasteners of the mixing device of the present invention are all made of high-temperature alloy steel. The specific grades are: the plates and pipes are made of nickel-based alloy NO6625, and the fasteners are made of NO7718. The surface roughness Ra of all materials is not greater than 12.5.

[0046] 2) In order to ensure the installation accuracy of the nozzle, the front baffle 5 and the rear baffle 8 are simultaneously positioned and cut with a high-power laser cutting machine to ensure that the radial processing deviation of the nozzle mounting holes of the front and rear baffles meets the nozzle installation requirements.

[0047] 3) The nozzle 3 is positioned and cut using a single tube. Multi-tube welding is strictly prohibited. At the same time, the guide groove at the front end of the nozzle should be able to ensure the installation accuracy of the first limit block 17. The small holes in the nozzle 3 should be opened by laser or water jet, and the total opening area should be strictly controlled to meet the design requirements.

[0048] 4) The front baffle 5 and the rear baffle 8 are clamped by positioning fixtures, inserted into the nozzle 3 in sequence, and clamped and positioned at the ports.

[0049] 5) The parallelism deviation between the centerline of the installed nozzle and the connecting line of the front and rear baffle centers should be no greater than 1mm. After centering the nozzle 3, install the first threaded seat 12, first threaded plug 13, round gasket 14, and C-shaped gasket 15 on the front and rear baffles and tighten them into place. Simultaneously, install the second threaded seat 19, second threaded plug 20, metal sealing gasket 18, and transition seat 21 on the rear baffle 8 and tighten them into place. After the nozzle 3 installation accuracy inspection meets the requirements, spot weld the transition seat 21 to the nozzle 3. Then, weld the first threaded seat 12 and second threaded seat 19 to the front and rear baffles, respectively.

[0050] 6) After the threaded seat is welded, adjust the tightening torque of the first threaded plug 13 and round nut 16. First, tighten the first threaded plug 13 and mark the position to confirm it. Then tighten the round nut 16 to a tightening torque of 70 Nm. The first threaded plug 13 must not rotate during the tightening of the round nut 16. After tightening, spot weld the round nut 16 to the first threaded seat 12 to prevent it from loosening.

[0051] 7) After the round nut 16 is installed, weld the first limit block 17 and the first threaded plug 13 to fix them, and adjust the tightening torque of the second threaded plug 20 to 400Nm. Then, weld the second limit blocks 22 for preventing loosening at appropriate positions on the second threaded seat 19 and the second threaded plug 20 respectively. The second limit blocks 22 must be tightly fitted without any gaps, and the overlap length must be no less than 10mm.

[0052] 8) The three layers of insulation boards are accurately positioned and installed at one time. The two inner layers of insulation boards are rounded and cut in the contact areas with the outer cover of the partition. The outer partition is rounded to ensure that the overall outer diameter meets the result requirements. Square partitions are used to fill and weld the horizontal support of the baffle.

[0053] The specific implementation process of the mixing principle of the mixing device provided in the above embodiment is as follows:

[0054] 1) According to the test state requirements, the main air supply line supplies low-temperature air that meets the mixing requirements, and the bypass line supplies high-temperature air after the heater. In order to achieve mixing, it is necessary to control the pressure ratio and flow ratio of the high / low temperature air flow within the appropriate range, with the pressure ratio between 1.05 and 1.5 and the flow ratio between 0.0 and 40.0.

[0055] 2) According to the temperature conditions required by the test state, appropriately adjust the air flow and pressure ratio of high and low temperature airflows, and make fine adjustments based on actual test requirements.

[0056] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention shall be included within the scope of protection of the present invention. The above description is merely a preferred embodiment of the present invention. It should be noted that those skilled in the art can make various improvements and variations without departing from the technical principles of the present invention, and such improvements and variations shall also be considered within the scope of protection of the present invention.

Claims

1. A mixing device for combined power high altitude simulation test, wherein the mixing device is arranged inside a stabilizing chamber, characterized in that: The mixing device includes multiple nozzles, front baffles and rear baffles arranged at both ends of the nozzles, the front baffles and rear baffles are connected to the cylinder support through a support seat, three layers of heat insulation plates are arranged in the nozzles, the nozzles are slidably connected to the front baffles and fixedly connected to the rear baffles, The sum of the total equivalent area of the nozzle is the same as the flow area of the main air supply pipeline. The sum of the equivalent areas of the staggered small holes in each nozzle is the same as the flow area of the high-temperature airflow. The high-temperature hot airflow enters the nozzle through the small holes and mixes with the main air supply in the nozzle. A transition seat is fixed downstream of the nozzle, and the nozzle is fixed to the rear baffle through a second threaded seat, a second threaded plug and a transition seat. The second threaded plug presses the transition seat onto the second threaded seat, and a metal sealing gasket is provided on the pressing surface. The second threaded seat and the second threaded plug are respectively fixed with second limit blocks that fit tightly to prevent loosening. The overlap length of the second limit block fixed on the second threaded seat and the second limit block fixed on the second threaded plug is not less than 10 mm.

2. The mixing device for combined power high altitude simulation test according to claim 1, characterized in that: The support seat is arranged at the waist of the mixing device, and there are multiple support seats. An expansion space is reserved between the front baffle and the cylinder.

3. The mixing device for combined power high altitude simulation test according to claim 2, characterized in that: Eight support seats are evenly arranged at the upstream and downstream positions of the front baffle and the rear baffle.

4. The mixing device for combined power high altitude simulation test according to claim 1, characterized in that: The front baffle and the cylinder are sealed by a C-shaped gasket.

5. The mixing device for combined power high altitude simulation test according to claim 4, characterized in that: A first threaded seat is fixed on the front baffle, and the nozzle is fixed to the front baffle through a first threaded plug, a first threaded seat and a first limit block. The first threaded plug and the first threaded seat are locked by a round nut. A metal round gasket and a C-shaped gasket for sealing are provided between the first threaded plug and the first threaded seat. The first threaded plug presses the metal round gasket and the C-shaped gasket to achieve a sealing effect.

6. The mixing device for combined power high altitude simulation test according to claim 5, characterized in that: The surfaces of the connection areas between the nozzle, front baffle and C-shaped gasket are finely machined to achieve a tight seal.

7. The mixing device for combined power high altitude simulation test according to claim 5, characterized in that: The nozzle is processed from a whole pipe, and a guide groove is provided at an upstream end of the nozzle. The first limit block is arranged in the guide groove, and the first limit block is fixed to the first threaded plug by welding.

8. The mixing device for combined power high altitude simulation test according to claim 1, characterized in that: The parallelism deviation between the center line of the nozzle and the connecting line of the center lines of the front baffle and the rear baffle is no more than 1 mm.

9. The mixing device for combined power high altitude simulation test according to claim 1, characterized in that: A front heat insulation plate front cover and a heat insulation plate annular cover are also provided upstream of the nozzle. The front heat insulation plate front cover is supported and fixed by the front heat insulation plate front cover. A sealing ring supported and fixed by a sealing ring is provided between the nozzle and the barrel.

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