Experimental setup for thermoacoustic oscillation research

Abstract

The present invention provides an experimental device for thermoacoustic oscillation research. The experimental device includes an outer tube, an inner tube, an exciter, an outer sensor and an inner sensor. The outer tube has an outer flow channel for the flow of a first gas, the inner tube has an inner flow channel for the flow of a second gas, the outer sensor and the inner sensor are both installed on the outer tube, the outer sensor is used to detect the parameters of the first gas in the outer flow channel, and the inner sensor is used to detect the parameters of the second gas in the inner flow channel; the exciter includes a loudspeaker, and at least one of the outer tube and the inner tube is connected to the exciter. This experimental device can help experimenters explore the influence of sound excitation on the flow of fluids in a dual-jet system, as well as the influence of sound excitation on the combustion of the flame downstream of the dual-jet system, which is beneficial to assisting experimenters in simulating and researching the thermoacoustic oscillation problem in an aero-engine's dual-jet system.

Description

Technical Field

[0001] The present invention relates to the field of aerospace experimental equipment, and in particular to an experimental device for studying thermoacoustic oscillation. Background Art

[0002] In order to study the thermoacoustic oscillation problem inside an aerospace engine, some researchers simulate and study the air flow situation inside the injector or the combustion situation downstream of the injector through some experimental devices; moreover, some researchers apply sound excitation to the air flow in the experimental device to further study the influence of the thermoacoustic oscillation inside the engine on the flow of the engine fuel inside the injector and the influence on the combustion of the flame downstream of the injector.

[0003] Some existing aerospace engines have a double-injection system for their injection system (i.e., an injector with a dual gas path); however, it is difficult for existing experimental devices to simulate and study the double-injection system in an aeroengine. Although some existing experimental devices have dual pipelines, these devices can only measure the fluid parameters of the outer pipeline upstream of the injector and cannot detect the fluid parameters in the inner pipeline and the relevant parameters downstream of the injector, which causes experimenters to be unable to conduct comprehensive research. Summary of the Invention

[0004] The present invention aims to solve at least one of the technical problems existing in the prior art. For this purpose, the present invention provides an experimental device for studying thermoacoustic oscillation. This experimental device can simultaneously detect the parameters of the fluid in the outer tube and the parameters of the fluid in the inner tube. This experimental device can explore the influence of thermo-acoustic coupling oscillation on the flow situation of the fluid in the double-injection system, explore the influence of thermo-acoustic coupling oscillation on the combustion characteristics of the flame downstream of the double-injection system, and explore the influence of thermo-acoustic coupling oscillation on the sound field structure upstream and downstream of the flame, so as to facilitate exploring the interaction between flame heat release and sound, explaining its generation and coupling mechanism, and further guiding the design of aerospace engines and solving the problem of combustion instability.

[0005] The experimental device for studying thermoacoustic oscillation according to an embodiment of the present invention includes: an outer tube with an outer flow channel inside, and the outer flow channel is for the first gas to flow; an inner tube with an inner flow channel inside, and the inner flow channel is for the second gas to flow. The inner tube includes a penetrating part, and the penetrating part is arranged in the outer flow channel, and there is a gap between the outer wall of the penetrating part and the inner wall of the outer tube; an outer sensor installed on the outer tube, and the outer sensor is used to detect the pressure or flow rate or sound pressure of the first gas in the outer flow channel; an inner sensor installed on the inner tube, and the inner sensor is used to detect the pressure or flow rate or sound pressure of the second gas in the inner flow channel; at least one exciter, the exciter includes a loudspeaker, and at least one of the outer tube and the inner tube is connected to the exciter.

[0006] The experimental device for thermoacoustic oscillation research according to the embodiments of the present invention has at least the following beneficial effects: In the experimental device provided by the present invention, the combination of the outer tube and the inner tube is equivalent to an injector with a dual gas path. The outer flow path is one of the gas paths of the dual gas path injector, and the inner flow path is the other gas path. The sound emitted by the loudspeaker can be used to perturb the fluid. With this experimental device, the experimenter can inject gases into the outer tube and the inner tube, and use the sound of the loudspeaker to excite the gas in the outer flow path or the inner flow path. Subsequently, the experimenter can collect the parameters of the first gas in the outer flow path and the parameters of the second gas in the inner flow path, and study and analyze the influence of the sound of the loudspeaker on the gas flow of the injector through these collected data. The experimenter can also observe the combustion situation of the flame at the outlets of the outer tube and the inner tube to analyze the influence of the sound of the loudspeaker on the combustion of the injector. For example, parameters such as the frequency and amplitude of the sound emitted by the loudspeaker can be adjusted to observe the response of the flame at different frequencies or amplitudes. This experimental device can measure the parameters of the fluids in the outer tube and the inner tube simultaneously. This experimental device enables the experimenter to explore the influence of the sound of the loudspeaker on the fluid flow in the dual injector system and the influence of the sound of the loudspeaker on the combustion of the flame downstream of the dual injector system, which is beneficial to assisting the experimenter in simulating and researching the thermoacoustic oscillation problem in the dual injector system of an aeroengine.

[0007] According to some embodiments of the present invention, it further includes a combustion tube, and the combustion tube is installed at the outlet end of the outer tube. The combustion tube has a combustion chamber for the flame to burn, and both the outer flow path and the inner flow path communicate with the combustion chamber.

[0008] According to some embodiments of the present invention, it further includes a combustion section sensor, and the combustion section sensor is installed on the combustion tube. The combustion section sensor is a temperature sensor, or a pressure sensor, or a flow velocity sensor.

[0009] According to some embodiments of the present invention, the combustion tube is detachably connected to the outer tube, and the combustion tube is made of a non-metallic transparent material, or the combustion tube is made of a metal material.

[0010] According to some embodiments of the present invention, it further includes a swirler, and the swirler is installed outside the penetrating portion. The swirler is arranged in the outer flow path and is located at the outlet end of the outer flow path. The swirler can make the first gas flowing through the swirler move circumferentially along the penetrating portion.

[0011] According to some embodiments of the present invention, it further includes a combustion tube and a pressing cylinder. The combustion tube is installed at the outlet end of the outer tube. The combustion tube has a combustion chamber for the flame to burn, and both the outer flow channel and the inner flow channel communicate with the combustion chamber. Along the axial direction of the pressing cylinder, one end of the pressing cylinder and the outer tube jointly clamp the swirler, and the other end of the pressing cylinder abuts against the combustion tube.

[0012] According to some embodiments of the present invention, the outer tube is connected to the actuator. The outer tube includes a detection part and an excitation part connected to each other. The actuator is connected to the excitation part, and the inner diameter of the excitation part is larger than the inner diameter of the detection part.

[0013] According to some embodiments of the present invention, the excitation part is connected to a plurality of the actuators, and the plurality of actuators are spaced apart along the circumferential direction of the excitation part.

[0014] According to some embodiments of the present invention, a plurality of outer sensors and a plurality of inner sensors are both provided. The plurality of outer sensors are spaced apart along the flow direction of the first gas, and the plurality of inner sensors are spaced apart along the flow direction of the second gas.

[0015] According to some embodiments of the present invention, it further includes a rectifying member. The rectifying member is arranged in the outer flow channel. The outer edge of the rectifying member is connected to the outer tube, and the inner tube penetrates through the rectifying member. The rectifying member has a plurality of rectifying holes for the first gas to pass through.

[0016] Additional aspects and advantages of the present invention will be given in part in the following description, become apparent in part from the following description, or be understood through the practice of the present invention. Description of the Drawings

[0017] The following further describes the present invention in conjunction with the drawings and embodiments, where:

[0018] Figure 1 is a three-dimensional schematic diagram of an experimental device in an embodiment of the present invention;

[0019] Figure 2 is Figure 1 the front view of the experimental device;

[0020] Figure 3 is Figure 1 the cross-sectional view of the experimental device in;

[0021] Figure 4 is Figure 1 the cross-sectional view of the experimental device in;

[0022] Figure 5 is Figure 3 the partial schematic diagram of the excitation part of the experimental device;

[0023] Figure 6 Schematic three-dimensional view of the outer tube of the experimental device for Figure 1 ;

[0024] Figure 7 Schematic view of the outer and inner pressure measuring tubes of the experimental device in Figure 3 ;

[0025] Figure 8 Assembly drawing of the outer and inner pressure measuring tubes of the experimental device in Figure 1 ;

[0026] Figure 9 Partial schematic view of the combustion tube of the experimental device in Figure 3 ;

[0027] Figure 10 Assembly drawing of the combustion tube, swirler and outer tube in Figure 9 ;

[0028] Figure 11 Cross-sectional view of the swirler in an embodiment of the present invention;

[0029] Figure 12 Schematic view of the flow rectifier in an embodiment of the present invention.

[0030] Reference numerals: 100 - experimental device, 101 - outer tube, 102 - inner tube, 103 - exciter, 104 - combustion tube, 105 - inner sensor, 106 - outer sensor, 107 - combustion section sensor, 108 - outer inlet joint, 109 - inner inlet joint, 201 - combustion chamber, 202 - detection part, 203 - excitation part, 204 - first connection part, 205 - loudspeaker, 206 - housing, 207 - cover, 208 - flow rectifier, 209 - penetrating part, 210 - exposed part, 301 - outer flow channel, 302 - first seal, 401 - inner flow channel, 501 - second connection part, 601 - inner pressure measuring tube, 602 - second connection cap, 603 - fourth seal, 604 - outer air passage plug, 605 - outer air passage pressing plate, 606 - third seal, 607 - outer pressure measuring tube, 608 - first connection cap, 609 - second seal, 801 - pressure cylinder, 802 - swirler, 1001 - inner cylinder, 1002 - blade, 1003 - outer cylinder, 1101 - rectifying hole, 1102 - penetrating hole. Detailed Description of the Invention

[0031] The embodiments of the present invention will be described in detail below. Examples of the embodiments are shown in the accompanying drawings, where the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below by referring to the accompanying drawings are exemplary only for explaining the present invention and should not be construed as limiting the present invention.

[0032] In the description of the present invention, it should be understood that for the orientation description, such as the orientation or positional relationship indicated by up, down, front, back, left, right, etc., is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present 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. Therefore, it should not be construed as a limitation to the present invention.

[0033] In the description of the present invention, the meaning of "several" is more than one, the meaning of "multiple" is more than two, and understandings such as "greater than", "less than", "exceeding", etc. do not include the recited number, and understandings such as "above", "below", "within", etc. include the recited number. If there is a description of "first" and "second", it is only for the purpose of distinguishing technical features and cannot be understood as indicating or implying relative importance or implicitly indicating the quantity of the indicated technical features or implicitly indicating the sequence relationship of the indicated technical features.

[0034] In the description of the present invention, unless otherwise clearly defined, words such as "set", "installed", "connected", etc. should be understood in a broad sense, and those skilled in the art can reasonably determine the specific meaning of the above words in the present invention in combination with the specific content of the technical solution.

[0035] In the description of the present invention, the description with reference to terms such as "one embodiment", "some embodiments", "schematic embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in a suitable manner in any one or more embodiments or examples.

[0036] The present invention provides an experimental device for thermoacoustic oscillation research (hereinafter referred to as the experimental device, corresponding reference numeral "100"). Referring to Figures 1 to 3 , the experimental device 100 includes an outer tube 101, an inner tube 102, an outer sensor 106, an inner sensor 105, and an exciter 103.

[0037] Referring to Figures 2 to 5, the interior of the outer tube 101 has an outer flow channel 301, that is, the lumen of the outer tube 101 is the outer flow channel 301, and the outer flow channel 301 is for the first gas to flow. The inner tube 102 includes a penetrating portion 209, the penetrating portion 209 is disposed inside the outer flow channel 301, and the inner wall of the outer tube 101 and the outer wall of the inner tube 102 are spaced apart to ensure that the outer flow channel 301 has sufficient space for the first gas to flow. The interior of the inner tube 102 has an inner flow channel 401, that is, the lumen of the inner tube 102 is the inner flow channel 401, and the inner flow channel 401 is for the second gas to flow. The combination of the outer tube 101 and the inner tube 102 is equivalent to a double-gas-path injector, the outer flow channel 301 is one gas path of the double-gas-path injector, and the inner flow channel 401 is the other gas path.

[0038] Referring to Figure 3 and Figure 4 , the actuator 103 includes a speaker 205 ( Figure 4 the speaker 205 is not specifically shown in Figure 3 and Figure 4 ). The speaker 205 can emit sound. At least one actuator 103 is provided, and at least one of the outer tube 101 and the inner tube 102 is connected to the actuator 103. Specifically, in some embodiments, only the outer tube 101 may be connected to the actuator 103, and the outer tube 101 may be connected to one or more actuators 103; in some embodiments, only the inner tube 102 may be connected to the actuator 103, and the inner tube 102 may be connected to one or more actuators 103; referring to Figure 3 and Figure 4 , in some embodiments, multiple actuators 103 may be provided, some of the actuators 103 are connected to the outer tube 101, and some of the actuators 103 are connected to the inner tube 102. The sound emitted by the speaker 205 in the actuator 103 will be transmitted to the first gas or the second gas, thereby affecting the flow of the first gas or the second gas.

[0039] For example, due to the propagation of sound, the sound emitted by the speaker 205 causes the vibration of the gas around the speaker 205, and this vibration is transmitted to the second gas in the inner flow channel 401, and this vibration will have a certain impact on the flow of the second gas. For example, this vibration will cause pressure pulsation and velocity pulsation of the second gas. The sound emitted by the speaker 205 is used to simulate the "thermoacoustic" generated during engine operation, and the influence of thermoacoustic on the flow of fluid can be simulated and experimented by applying the sound of the speaker 205 to the fluid.

[0040] The two names, the first gas and the second gas, are mainly used to distinguish the gas flowing in the outer flow channel 301 and the gas flowing in the inner flow channel 401. The specific types or components of the first gas and the second gas can be the same or different. For example, when using the experimental device 100 for experiments and research, if it is necessary to ignite the first gas or the second gas at the outlets of the outer tube 101 and the inner tube 102, the first gas can be a combustible gas such as methane, and the second gas can be a combustion-supporting gas such as oxygen (it can also be that the first gas is set as the combustion-supporting gas and the second gas is set as the combustible gas); in order to more realistically simulate the actual operation of the engine, it can also be considered to set the first gas or the second gas as the fuel gas specifically used by the engine. If it is only for studying the flow situation of the first gas in the outer tube 101 and the flow situation of the second gas in the inner tube 102, then in order to save costs, the first gas and the second gas can not be ignited, and both the first gas and the second gas can be set as air.

[0041] Both the outer sensor 106 and the inner sensor 105 are installed on the outer tube. The outer sensor 106 is used to detect the parameters of the first gas in the outer flow channel 301 (flow rate, or sound pressure, or pressure, or temperature, etc.), and the inner sensor 105 is used to detect the parameters of the second gas in the inner flow channel 401 (flow rate, or sound pressure, or pressure, or temperature, etc.). The pressure here specifically refers to the dynamic pressure of the fluid (the first gas or the second gas), and the sound pressure refers to the difference between the pressure when there is a sound field in the medium (the first gas or the second gas) and the pressure when there is no sound field. In order to measure the flow rate of the fluid, the outer sensor 106 or the inner sensor 105 can include a flow rate sensor; in order to measure the pressure or sound pressure of the fluid, the outer sensor 106 or the inner sensor 105 can include a pressure sensor; in order to measure the temperature of the fluid, the outer sensor 106 or the inner sensor 105 can include a temperature sensor. The specific structural principles of the temperature sensor, the pressure sensor, and the flow rate sensor belong to well-known technologies and will not be introduced in detail here.

[0042] The basic usage method of the experimental device 100 will be briefly introduced below.

[0043] After the experimental device 100 is assembled, without turning on the speaker 205, the first gas is introduced into the outer tube 101, and at the same time the second gas is introduced into the inner tube 102 (taking Figures 1 to 3 the direction as an example, the first gas and the second gas flow roughly from right to left), and the outer sensor 106 and the inner sensor 105 are started to collect the parameters of the first gas and at the same time collect the parameters of the second gas. In addition, the outlet ends of the outer tube 101 and the inner tube 102 are arranged adjacent to each other, and it is also possible to ignite at the outlet of the outer tube 101 to observe the combustion situation of the flame.

[0044] Subsequently, with the operating conditions unchanged, the speaker 205 can be turned on, and the sound pressure of the speaker 205 acts on the first gas or the second gas. At this time, the parameters of the first gas can be collected, and at the same time, the parameters of the second gas can be collected. Then, by comparing the data in the two states of the speaker 205 being turned on and off, the influence of the sound excitation of the speaker 205 on the gas flow can be analyzed. In addition, the influence of the frequency and loudness of the sound emitted by the speaker 205 on the gas flow can also be studied by changing the frequency and loudness of the sound.

[0045] During the experiment, different sensors can be replaced to obtain different data under the same operating conditions. For example, during a certain experimental period, the external sensor 106 can be set as a sound pressure sensor. After the experimenter obtains the sound pressure data of the first gas, the experimenter can adjust the external sensor 106 to a temperature sensor (equivalent to removing the sound pressure sensor from the outer tube 101 and then installing the temperature sensor on the outer tube 101) to obtain the temperature data of the first gas. Similarly, subsequently, the experimenter can also adjust the external sensor 106 to a pressure sensor and a flow rate sensor. The replacement and use of the internal sensor 105 are similar to those of the external sensor 106, and will not be repeated here.

[0046] In some embodiments, multiple external sensors 106 and multiple internal sensors 105 can be provided. The multiple external sensors 106 are spaced apart along the flow direction of the first gas, and the multiple internal sensors 105 are spaced apart along the flow direction of the second gas, so as to obtain the flow field data of the first gas and the flow field data of the second gas.

[0047] In the experimental device 100 provided by the present invention, the combination of the outer tube 101 and the inner tube 102 is equivalent to a double-gas-path injector. The outer flow channel 301 is one gas path of the double-gas-path injector, and the inner flow channel 401 is the other gas path. Using this experimental device 100, the experimenter can inject gases into the outer tube 101 and the inner tube 102, and use the sound of the speaker 205 to excite the gas in the outer flow channel 301 or the inner flow channel 401. Subsequently, the experimenter can collect the parameters of the first gas in the outer flow channel 301 and the parameters of the second gas in the inner flow channel 401, and study and analyze the influence of the sound of the speaker on the gas flow of the injector through these collected data; the experimenter can also observe the combustion situation of the flame at the outlets of the outer tube 101 and the inner tube 102 to analyze the influence of thermoacoustics on the combustion of the injector. This experimental device can simulate the influence of thermoacoustic coupling oscillation on the flow of the fluid in the double-injection system, as well as simulate the influence of thermoacoustic coupling oscillation on the combustion situation of the flame downstream of the double-injection system, which is beneficial to assisting the experimenter in simulating and studying the thermoacoustic oscillation problem in the double-injection system of an aeroengine.

[0048] It should be noted that along the length direction of the outer tube 101, the inner sensor 105 and the outer sensor 106 can be staggeredly arranged; of course, to avoid the structure of the experimental device 100 from being too complex, the inner sensor 105 on the inner tube 102 and the outer sensor 106 on the outer tube 101 can be arranged at the same position. In addition, for the experimental device 100 of the present invention, both the inner sensor 105 and the outer sensor 106 can be arranged at a position close to the outlet of the injector, so as to ensure that the experimenter can obtain the data of the fluid at the outlet near the injector, which is convenient for the user to comprehensively obtain the data of the fluid in the injector.

[0049] Referring to Figures 1 to 4 , in some embodiments, the experimental device 100 further includes a combustion tube 104. The combustion tube 104 is connected to the outlet end of the outer tube 101. The interior of the combustion tube 104 has a combustion chamber 201, that is, the lumen of the combustion tube 104 is the combustion chamber 201. The outer flow channel 301 and the inner flow channel 401 are both communicated with the combustion chamber 201. The first gas flows out of the outer tube 101 and then enters the combustion chamber 201, and the second gas flows out of the inner tube 102 and then enters the combustion chamber 201. The first gas and the second gas are mixed in the combustion chamber 201. If the experimenter ignites at one end of the combustion tube 104 far from the outer tube 101, the flame will burn in the combustion chamber 201. Arranging the combustion tube 104 can confine the range of the flame and improve the safety of the experimental device 100. To improve the service life of the combustion tube 104, the combustion tube 104 can be made of a high-temperature resistant material.

[0050] In some embodiments, the combustion tube 104 can be set to be transparent. For example, the combustion tube 104 is made of quartz glass. When the combustion tube 104 is transparent, the experimenter can use a camera to take pictures of the combustion of the flame in the combustion tube 104 through the combustion tube 104; that is, when the combustion tube 104 is transparent, the experimenter can perform optical measurement on the flame near the outlets of the inner tube 102 and the outer tube 101.

[0051] Referring to Figure 1 , in other embodiments, the experimental device 100 further includes a combustion section sensor 107. The combustion section sensor 107 can also be installed at the combustion tube 104. The combustion section sensor 107 is used to detect the parameters at the combustion tube 104, so that the experimenter can obtain the data of the combustion field at the outlet of the outer tube 101; it should be noted that the combustion section sensor 107 can be installed whether the combustion tube 104 is transparent or not. Specifically, the combustion section sensor 107 can be set as a temperature sensor, or a pressure sensor, or a flow rate sensor. For example, the combustion tube 104 can be set as a metal tube, and a thermocouple is attached to the outer surface of the metal tube to measure the temperature distribution of the wall surface of the combustion tube 104.

[0052] The combustion tube 104 can be detachably connected to the outer tube 101 (the detachable connection methods include but are not limited to screw connection), so that the combustion tube 104 can be replaced. When the combustion tube 104 is replaceable, in some test scenarios, if optical measurement is required, the combustion tube 104 made of non-metallic transparent material can be installed in the experimental device 100; in other test scenarios, if contact measurement is required to obtain specific parameters of the fluid, the transparent combustion tube 104 can be removed, and the combustion tube 104 made of metal material can be installed in the experimental device 100, and then the corresponding experiment can be carried out.

[0053] Referring to Figures 2 to 6 , in some embodiments, the outer tube 101 includes a detection part 202 and an excitation part 203. The detection part 202 is connected to the excitation part 203. The inner diameter of the excitation part 203 is larger than that of the detection part 202, and the excitation part 203 is connected to the exciter 103. The larger inner diameter of the excitation part 203 means that the space inside the excitation part 203 is larger (this space is part of the outer flow channel 301), and the space for the vibration of the first gas inside the excitation part 203 is larger, which is convenient for the sound emitted by the speaker 205 to act on the first gas.

[0054] Referring to Figure 5 and Figure 6 , the outer tube 101 further includes a first connection part 204. One end of the first connection part 204 is connected to the outside of the excitation part 203, and the other end of the first connection part 204 is connected to the exciter 103. Combining Figure 2 and Figure 5 , the exciter 103 includes a housing 206 and a speaker 205. The housing 206 is hollow, and the speaker 205 is installed inside the housing 206. For example, the speaker 205 is bonded to the housing 206 by glue. The housing 206 is connected to the first connection part 204. For example, one end of the first connection part 204 away from the excitation part 203 has a thread (not shown), and the housing 206 also has a thread, and the first connection part 204 and the housing 206 can be screwed together. The experimental device 100 further includes a first seal 302. The first connection part 204 and the housing 206 jointly clamp the first seal 302 (the first seal 302 can be made of an elastic material), so as to prevent the air in the environment where the experimental device 100 is located from entering the inside of the outer tube 101 through the gap between the first connection part 204 and the housing 206.

[0055] Figures 2 to 5 shows the case where the excitation part 203 is connected to multiple exciters 103. In some embodiments, the inner tube 102 can also be connected to multiple exciters 103. Referring to Figure 3, the inner tube 102 includes a penetrating portion 209 and an exposed portion 210 that are connected to each other. The exposed portion 210 is disposed outside the outer flow channel 301, and the exposed portion 210 has an inner inlet joint 109, and the inner inlet joint 109 is used to connect to a hose for conveying a second gas. Refer to Figure 4 , for the convenience of connecting the actuator 103 to the inner tube 102, the actuator 103 for connecting to the inner tube 102 can be connected to the exposed portion 210. When actuators 103 are connected to both the outer tube 101 and the inner tube 102, the actuator 103 on the outer tube 101 and the actuator 103 on the inner tube 102 can be turned on simultaneously during the experiment. When multiple actuators 103 are connected to the outer tube 101 or the inner tube 102, only some of the actuators 103 can also be started during the experiment.

[0056] Refer to Figures 1 to 4 , in some embodiments, the excitation portion 203 can be connected to multiple actuators 103, and the multiple actuators 103 are circumferentially spaced apart along the excitation portion 203. With this arrangement, the experimenter can turn on some of the actuators 103 connected to the excitation portion 203, so as to use the experimental device 100 to study the influence of sound waves generated by sound sources in different directions on the flow of the fluid. For example, within a certain time period, only the actuator 103 located above and connected to the outer tube 101 is turned on, and then data is collected through the outer sensor 106 and the inner sensor 105; subsequently, within another time period, only the actuator 103 located on the left and connected to the outer tube 101 is turned on, and then data is collected again through the outer sensor 106 and the inner sensor 105. The feasible usage methods are not listed one by one here.

[0057] Refer to Figure 5 , the outer tube 101 further includes a cover body 207, the cover body 207 is connected to the excitation portion 203, and the inner tube 102 penetrates through the cover body 207. Combining Figure 1 , an outer inlet joint 108 for the first gas to enter is provided on the cover body 207. The outer inlet joint 108 allows the first gas to enter the outer flow channel 301, and the outer inlet joint 108 can be connected to a hose for providing the first gas.

[0058] Refer to Figure 3 and Figure 5 , in some embodiments, the outer shell further includes a rectifying member 208, the rectifying member 208 is installed in the outer flow channel 301, the outer edge of the rectifying member 208 is connected to the outer tube 101, and the rectifying member 208 is disposed at the inlet end of the outer tube 101. The rectifying member 208 has a plurality of rectifying holes 1101, and the rectifying holes 1101 allow the first gas to pass through. Combining Figure 1 and Figure 5, the cover 207 can be set as a flange. The cover 207 and the excitation part 203 are connected by screws or bolts and jointly clamp the outer edge of the rectifier 208, thereby fixing the rectifier 208. The rectifier 208 can be made of porous foam metal, and the rectifying holes 1101 are the pores of the porous foam metal itself; or, as Figure 12 shown, the rectifier 208 can be set as an orifice plate. For example, the rectifier 208 is set as a plastic plate, a metal plate, etc. with a plurality of through holes, and these through holes serve as the rectifying holes 1101. In the case where the rectifying holes 1101 are provided, after the first gas flows through the rectifier 208, it will flow dispersedly, and the air flow of the first gas is more uniform, thereby ensuring that both the pressure pulsation and the velocity pulsation of the air flow of the first gas in the outer tube 101 are caused by the applied sound excitation. Figure 12 In, the rectifier 208 has a through hole 1102 at the center, and the through hole 1102 is for the through part 209 of the inner tube 102 to pass through.

[0059] Referring to Figure 9 and Figure 10 , in some embodiments, the experimental device 100 further includes a swirler 802. The swirler 802 is installed outside the inner tube 102, the swirler 802 is arranged in the outer flow channel 301, and the swirler 802 is arranged at the outlet end of the outer flow channel 301. The swirler 802 is used to make the first gas generate a swirl after flowing out of the outer tube 101, so that the experimental device 100 can simulate the operation of a jet injection system that can generate a swirl.

[0060] Specifically, referring to Figure 11 , the swirler 802 can include an inner cylinder 1001 and blades 1002. The inner cylinder 1001 is sleeved outside the inner tube 102, and a plurality of blades 1002 are provided. The blades 1002 are connected to the outside of the inner cylinder 1001. Along the axial direction of the inner cylinder 1001, the blades 1002 include a first end and a second end. Figure 11 In, the left end of the blade 1002 is the first end, the right end of the blade 1002 is the second end, and the first end and the second end are spaced apart along the circumferential direction of the inner cylinder 1001. When the first gas flows through the blade 1002, it will flow along the surface of the blade 1002, and the first gas moves along the circumferential direction of the inner tube 102 (specifically, the circumferential direction of the through part 209), thereby generating a swirl. When the first gas passes through the swirler 802, the swirler 802 can rotate relative to the inner tube 102 under the action of the air flow; or, the swirler 802 can also be sleeved outside the inner tube 102 in a form that cannot rotate relative to the inner tube 102. Referring to Figure 11 , in some embodiments, in order to enhance the structural strength and shape stability of the blade 1002, the swirler 802 can further include an outer cylinder 1003. The outer edge of the blade 1002 is connected to the outer cylinder 1003, and the outer surface of the outer cylinder 1003 abuts against the inner wall of the outer tube 101.

[0061] Referring to Figure 9 and Figure 10 , in some embodiments, the experimental device 100 further includes a pressure cylinder 801. The combustion tube 104 is connected to the outlet end of the outer tube 101 (for example, the two are fixed to each other by means of threaded connection). One end of the pressure cylinder 801 is abutted by the combustion tube 104, the other end of the pressure cylinder 801 is abutted by the swirler 802, and the end of the swirler 802 away from the pressure cylinder 801 is abutted by the outer tube 101. That is, the pressure cylinder 801 and the outer tube 101 jointly clamp the swirler 802, and the combustion tube 104 presses the pressure cylinder 801 tightly, thereby preventing the swirler 802 from coming out of the outer tube 101. Fixing the swirler 802 by pressing the pressure cylinder 801 tightly by the combustion tube 104 and pressing the swirler 802 tightly by the pressure cylinder 801 is beneficial to simplifying the structural complexity of the experimental device 100 and increasing the assembly convenience of the experimental device 100.

[0062] In addition, in this setting mode, when it is necessary to replace the swirler 802 with different axial lengths, the pressure cylinder 801 with different axial lengths can be replaced together so that the experimental device 100 can be provided with swirler 802 with different lengths. For example, when the axial length of the swirler 802 is longer, a pressure cylinder 801 with a shorter axial length can be replaced.

[0063] In the case where the swirler 802 is provided, the swirler 802 can prevent flame flashback; and the diameter of the inner tube 102 is relatively small, and the flame is not likely to flash back either.

[0064] Along the flow direction of the first gas, the excitation part 203 is located upstream of the detection part 202; the outer sensor 106 is installed on the detection part 202. The outer tube 101 further includes a second connection part 501, the second connection part 501 is connected to the outer tube 101, and an outer sensor 106 and an inner sensor 105 can be installed on the same second connection part 501 to reduce the structural complexity and processing difficulty of the outer tube 101.

[0065] For a pressure sensor and a Pitot tube type flow velocity sensor, the sensor needs to have a gas guide component inserted into the outer tube 101 or the inner tube 102. Therefore, referring to Figure 7 and Figure 8, in some embodiments, the outer sensor 106 includes an outer piezometric tube 607. The outer piezometric tube 607 penetrates through the second connection part 501 so that the lumen of the outer piezometric tube 607 communicates with the outer flow passage 301, enabling the outer sensor 106 to detect the pressure of the fluid. The experimental device 100 further includes a first connection cap 608 and a second seal 609. The first connection cap 608 is connected to the second connection part 501 (for example, the two are threadedly connected), and the outer piezometric tube 607 penetrates through the first connection cap 608 and the second connection part 501; the second seal 609 is clamped by the first connection cap 608 and the second connection part 501, thereby preventing external air from entering the outer flow passage 301 through the gap between the outer piezometric tube 607 and the second connection part 501, and preventing the first gas in the outer tube 101 from leaking.

[0066] Similarly, referring to Figure 7 and Figure 8 , the experimental device 100 further includes an outer air passage plug 604, an outer air passage pressing plate 605, and a second connection cap 602. The inner sensor 105 includes an inner piezometric tube 601. The outer air passage plug 604 is received in the second connection part 501, and the outer air passage plug 604 is threadedly connected to the second connection cap 602. The outer air passage pressing plate 605 is connected to the second connection part 501 by bolts or screws, and the outer air passage pressing plate 605 presses the outer air passage plug 604. The inner piezometric tube 601 penetrates through the second connection cap 602 and the outer air passage plug 604, and the inner piezometric tube 601 passes through the second connection part 501. The lumen of the inner piezometric tube 601 communicates with the inner flow passage 401. To prevent air in the environment from entering the outer flow passage 301 or the inner flow passage 401, and to prevent the second gas from leaking from the inner tube 102 to the external environment, the experimental device 100 further includes a third seal 606 and a fourth seal 603. A third seal 606 can be provided between the second connection part 501 and the outer air passage plug 604, and between the outer air passage plug 604 and the outer air passage pressing plate 605. A fourth seal 603 is provided between the second connection cap 602 and the outer air passage plug 604.

[0067] If the outer sensor 106 and the inner sensor 105 are set as temperature sensors, the outer piezometric tube 607 or the inner piezometric tube 601 may not be provided; for example, a thermocouple can be directly attached to the outer wall of the inner tube 102 or the outer wall of the outer tube 101. Or, the outer sensor 106 and the inner sensor 105 can specifically be set as hot-wire anemometers (for measuring flow velocity), and the outer piezometric tube 607 and the inner piezometric tube 601 fixed to the second connection part can be replaced with the fine metal wires (hot wires) of the hot-wire anemometer.

[0068] The embodiments of the present invention have been described in detail above with reference to the accompanying drawings. However, the present invention is not limited to the above embodiments, and various changes can be made without departing from the spirit of the present invention within the scope of knowledge possessed by those of ordinary skill in the art. In addition, the embodiments of the present invention and the features in the embodiments can be combined with each other without conflict.

Claims

1. An experimental device for thermoacoustic oscillation research, characterized in that, Comprising: An outer tube with an outer flow channel inside, and the outer flow channel is for the first gas to flow through; An inner tube with an inner flow channel inside, and the inner flow channel is for the second gas to flow through. The inner tube includes a penetrating portion which is arranged in the outer flow channel, and there is a gap between the outer wall of the penetrating portion and the inner wall of the outer tube; An outer sensor installed on the outer tube, and the outer sensor is used to detect the parameters of the first gas in the outer flow channel; An inner sensor installed on the inner tube, and the inner sensor is used to detect the parameters of the second gas in the inner flow channel. There are multiple outer sensors and multiple inner sensors. The multiple outer sensors are spaced apart along the flow direction of the first gas, and the multiple inner sensors are spaced apart along the flow direction of the second gas; Multiple exciters, and each exciter includes a loudspeaker. A part of the exciters is connected to the outer tube, and another part of the exciters is connected to the inner tube; A combustion tube installed at the outlet end of the outer tube. The combustion tube has a combustion chamber for the flame to burn, and both the outer flow channel and the inner flow channel communicate with the combustion chamber.

2. The experimental device for thermoacoustic oscillation research according to claim 1, characterized in that, It further includes a combustion section sensor installed on the combustion tube, and the combustion section sensor is a temperature sensor, or a pressure sensor, or a flow velocity sensor.

3. The experimental device for thermoacoustic oscillation research according to claim 1 or 2, characterized in that, The combustion tube is detachably connected to the outer tube; the combustion tube is made of a non-metallic transparent material, or the combustion tube is made of a metal material.

4. The experimental device for thermoacoustic oscillation research according to claim 1, characterized in that, It further includes a swirler installed outside the penetrating portion. The swirler is arranged in the outer flow channel and is located at the outlet end of the outer flow channel. The swirler can make the first gas flowing through the swirler move circumferentially along the penetrating portion.

5. The experimental apparatus for thermoacoustic oscillation research according to claim 4, characterized in that, It further includes a combustion tube and a pressing cylinder. The combustion tube is installed at the outlet end of the outer tube. The combustion tube has a combustion chamber for the flame to burn, and both the outer flow channel and the inner flow channel communicate with the combustion chamber; Along the axial direction of the pressing cylinder, one end of the pressing cylinder and the outer tube jointly clamp the swirler, and the other end of the pressing cylinder abuts against the combustion tube.

6. The experimental device for thermoacoustic oscillation research according to claim 1, characterized in that, The outer tube includes a detection portion and an excitation portion which are connected to each other. The exciter is connected to the excitation portion, and the inner diameter of the excitation portion is larger than that of the detection portion.

7. The experimental device for thermoacoustic oscillation research according to claim 6, characterized in that, The excitation portion is connected to multiple exciters, and the multiple exciters are spaced apart along the circumferential direction of the excitation portion.

8. The experimental device for thermoacoustic oscillation research according to claim 1, characterized in that, It further includes a rectifying member arranged in the outer flow channel. The outer edge of the rectifying member is connected to the outer tube, and the inner tube penetrates through the rectifying member; the rectifying member has multiple rectifying holes for the first gas to pass through.

Images