Thermal protection material ablation process monitoring system based on mass spectrometer

Abstract

The invention provides a thermal protection material ablation process monitoring system based on a mass spectrometer, and the system comprises an arc heater which is used for heating a gas medium filled in the arc heater, and the formed high-temperature gas passes through a spray pipe and forms a test flow field required by a test at an outlet; the model support is arranged at the outlet of the spray pipe, the test model is installed on the model support, and the test flow field acts on the test model; the sampler is arranged at the downstream of the test model and is used for collecting gas-phase ablation products generated by the test model under the action of the high-temperature gas; the sampler is communicated with the mass spectrometer and conveys a sample to the mass spectrometer for analysis; and the mass spectrometer is in data connection with the data analysis terminal to record, store and display data of the mass spectrometer. Through in-situ sampling in high-speed and high-temperature airflow and dust removal, heat preservation and conveying of samples, detection equipment is prevented from facing a severe test environment, and meanwhile, by combining the characteristics of wide measurement range and quick response of a mass spectrometer, real-time analysis of components of an ablation product is realized.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of aircraft ground test, in particular to a heat-resistant material ablation process monitoring system based on a mass spectrometer. BACKGROUND

[0002] A hypersonic vehicle faces aerodynamic heating caused by compression shock and gas friction during flight, and often needs a thermal protection system to ensure the safety of the vehicle. Ground testing is an important way to screen heat-resistant materials and evaluate heat-resistant schemes. Currently, high-temperature and high-speed gas flow generated by an electric arc heater or a gas flow heater is directly used on a test model to evaluate the heat-resistant material or scheme. The feasibility of the heat-resistant scheme is evaluated by recording and analyzing the model temperature and the change in the model shape during the test. Although the above-mentioned indicators are easy to implement and quantify, the description of the ablation process is still not intuitive.

[0003] A heat-resistant ablation structure is at the expense of the mass loss of heat-resistant materials. After being heated, the materials form gaseous products through pyrolysis, sublimation and other ways to block heat. Therefore, a detection method for directly sampling and analyzing gaseous ablation products is needed to intuitively evaluate the ablation behavior of heat-resistant materials.

[0004] Conventional gas component analysis methods include chromatography, spectroscopy and mass spectrometry. Compared with the other methods, mass spectrometry has the characteristics of high sensitivity, wide measurement range and fast reaction speed, and is more suitable for the test environment and test requirements of heat-resistant material ablation tests. SUMMARY

[0005] The present application aims to provide a heat-resistant material ablation process monitoring system based on a mass spectrometer, which can be applied to the detection and analysis of gaseous ablation products in heat-resistant material ablation tests, and extract more effective data during the ablation test for the reference of model and material units. The present application provides a heat-resistant material ablation process monitoring system based on a mass spectrometer, which comprises: an electric arc heater, which heats the gas medium filled in the electric arc heater by electric arc heating; a nozzle, through which the high-temperature gas formed by the electric arc heater passes and forms a test flow field required for the test at the outlet; a model support and a test model, the model support is arranged at the outlet of the nozzle, the test model is installed on the model support, and the test flow field acts on the test model; a sampler, which is arranged downstream of the test model and collects gaseous ablation products generated by the test model under the action of high-temperature gas; a mass spectrometer, which is in communication with the sampler and transports the sample to the mass spectrometer for analysis; and a data analysis terminal, which is in data connection with the mass spectrometer, and records, stores and displays the data of the mass spectrometer.

[0006] Further, a gas pipeline is further included, and the sampler is in communication with the mass spectrometer through the gas pipeline.

[0007] Further, the electric arc heater is one of a tube type electric arc heater, a segmented electric arc heater, a laminated electric arc heater or an alternating current electric arc heater.

[0008] Further, the nozzle is a Laval nozzle, and is one of an axisymmetric conical nozzle, a rectangular nozzle or an elliptical nozzle.

[0009] Further, the model support is made of a heat-conducting metal, and a water cooling channel is arranged on the model support.

[0010] Further, the test model is a flat plate, a stagnation point or a leading edge shape, and a surface layer of the test model is covered with an ablative pyrolytic heat-resistant material.

[0011] Further, a surface of the sampler in contact with the gas flow is a natural extension of a surface of the test model.

[0012] Further, the sampler is a heat-conducting metal-made partition structure, and a gas channel is arranged inside the sampler, and a water cooling channel is arranged outside the sampler; the sampler is provided with a micropore at a top portion and a metal pipe at a bottom portion.

[0013] Further, a gas filter is arranged in series with the gas pipeline, and a heat tracing assembly is arranged on the gas pipeline.

[0014] Further, the mass spectrometer is connected with and in communication with the data analysis terminal through an optical fiber.

[0015] The technical scheme of the present application forms a high-temperature gas test flow field through the electric arc heater and the nozzle, collects the gaseous ablation products generated by the test model placed downstream of the nozzle outlet under the action of the high-temperature gas, and transports the sample to the mass spectrometer for analysis, and the analysis signal enters the data analysis terminal for recording, storage and display. Through in-situ sampling in the high-speed high-temperature gas flow and dust removal, heat preservation and transportation of the sample, the detection equipment is prevented from facing a harsh test environment, and the characteristics of wide measurement range and fast response of the mass spectrometer are combined to realize real-time analysis of the ablation product components, deeply understand the ablation response behavior of the heat-resistant material, and monitor and analyze the ablation process of the heat-resistant material from the chemical reaction angle. BRIEF DESCRIPTION OF DRAWINGS

[0016] In order to more clearly illustrate the specific embodiments of the present application or the technical scheme in the prior art, the drawings needed in the following specific embodiment or prior art description will be briefly introduced. Obviously, the drawings in the following description are some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor.

[0017] Figure 1 This is a schematic diagram of the monitoring system of the present invention; Explanation of reference numerals in the attached figures: 1-Arc heater; 2-Nozzle; 3-Experimental model; 4-Model support; 5-Sampler; 6-Gas pipeline; 7-Mass spectrometer; 8-Data analysis terminal. Detailed Implementation

[0018] The technical solution of the present invention will be clearly and completely described below with reference to the embodiments. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0019] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," and "counterclockwise," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting this invention.

[0020] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the stated features. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified. Furthermore, the terms "installed," "connected," and "linked" should be interpreted broadly; for example, they may refer to a fixed connection, a detachable connection, or an integral connection; they may refer to a mechanical connection or an electrical connection; they may refer to a direct connection or an indirect connection through an intermediate medium; and they may refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0021] Example 1 like Figure 1 As shown, the present invention provides a monitoring system for the ablation process of heat-resistant materials based on mass spectrometry, including an arc heater 1, a nozzle 2, an experimental model 3, a model support 4, a sampler 5, a gas pipeline 6, a mass spectrometer 7, and a data analysis terminal 8; The electric arc heater 1 generates an electric arc to heat the gas medium filled in the electric arc heater 1, and the high-temperature and high-pressure gas generated enters the Laval nozzle 2 to form a supersonic test flow field at the outlet of the Laval nozzle 2. The test model 3 is placed near the downstream of the outlet of the Laval nozzle 2, and the model support 4 is used to fix and support the test model 3. After the test gas flow flows out of the Laval nozzle 2, the test gas flow directly acts on the test model 3 and the model support 4. The model support 4 is cooled by the cooling water in the water cooling channel to ensure that the model support 4 is not damaged in the high-temperature flow field. The test model 3 is heated by the gas flow to undergo an ablation process and generate gaseous ablation products. The sampler 5 collects the generated gaseous ablation products, and the gaseous ablation products are transported into the mass spectrometer 7 after being heat-insulated and dedusted by the gas pipeline 6. The data generated by the mass spectrometer 7 are transmitted to the data analysis terminal 8 for recording, storage and display.

[0022] The electric arc heater 1 can be one of a tubular, segmented, laminated and alternating current electric arc heater, and the normal-temperature gas is heated to a high-temperature state by an electric arc heating method. The heater operates for a time t1, t1≥10s, and the enthalpy value of the generated high-temperature gas can reach 500kJ / kg~20000kJ / kg, which can meet the needs of the aerodynamic thermal protection ground test of the aircraft.

[0023] The Laval nozzle 2 is a supersonic nozzle with a nominal Mach number of 1.4~6.5. According to the test model and the test state, the Laval nozzle 2 can be one of a conical, rectangular and elliptical nozzle. The gas flowing out of the Laval nozzle 2 forms a supersonic flow field required for the test to achieve the test conditions required by the model.

[0024] The test model 3 can have a flat plate, stagnation point or leading edge shape, or other specified shapes, and the surface layer is covered with carbon-based, silicon-based or resin-based ablation pyrolysis heat protection materials.

[0025] The model support 4 adopts a high-pressure water cooling design, and the cooling water pressure is 1MPa~5MPa. The model support 4 can stay in the high-temperature flow field of the electric arc wind tunnel for a time t2, t2≥t1, and the existence of the model support 4 does not interfere with the test flow field and the ablation process.

[0026] The sampler 5 is made of a metal with good thermal conductivity, and the thermal conductivity is greater than 50W / m.K. As an optional solution, the sampler 5 can be red copper. The sampler 5 is installed behind the test model, and the surface of the sampler 5 in contact with the gas flow is a natural extension of the surface of the test model to avoid direct exposure to the gas flow or interference with the flow field. The sampler has a partition wall structure, and the inside is a gas channel and the outside is a water cooling channel. The cooling water pressure is 1MPa~5MPa. The top of the sampler 5 is provided with micropores with a pore size of 0.01mm~3mm, and the bottom is provided with a metal pipe with an inner diameter of 1mm~5mm. By optimizing the shape of the sampler, the position of the sampler and the model, reasonably selecting the material and designing the water cooling, the sampler 5 can stay in the high-temperature flow field for a long time without interfering with the flow field.

[0027] The gas pipeline 6 is made of stainless steel, connected with the bottom metal pipe of the sampler through a sleeve, and a gas filter with a filtering accuracy of 5-50 microns is connected in series in the pipeline. The gas pipeline is kept at a constant temperature of 180-250 DEG C through a heating belt.

[0028] The mass spectrometer 7 has a scanning mass number range of 1-200 amu, a mass spectrometer scanning resolution of greater than 0.5 amu, a mass spectrometer detection limit of greater than 1 ppm, a mass spectrometer stability of less than ±0.5% or 0.1 amu / 24h (24h fluctuation of not more than 0.1 amu), and a mass spectrometer fastest scanning speed of less than 1 ms. The mass spectrometer can realize analysis and detection of conventional organic and inorganic components in the ablation process, meet the needs of long-time detection of the ablation test, and realize the detection purpose with a small equipment cost.

[0029] The data analysis terminal 8 is connected and communicated with the mass spectrometer through an optical fiber, can realize remote control of the mass spectrometer, and can record, store and display the data generated by the mass spectrometer.

[0030] The part not described in detail in the present application belongs to the common knowledge of those skilled in the art.

[0031] Finally, it should be pointed out that: the above embodiments are only used to illustrate the technical solutions of the present application, and not to limit them; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that: it can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacement for part or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A mass spectrometer-based monitoring system for the ablation process of heat-resistant materials, characterized in that, include: An electric arc heater (1) heats the gas medium inside it by means of electric arc heating; The high-temperature gas generated by the electric arc heater (1) passes through the nozzle (2) and forms the test flow field required for the test at the outlet; The model support (4) and the test model (3) are provided. The model support (4) is located at the outlet of the nozzle (2), and the test model (3) is installed on the model support (4). The test flow field acts on the test model (3). Sampler (5), the sampler (5) is arranged downstream of the test model (3) to collect the gas phase ablation products generated by the test model (3) under the action of high temperature gas; Mass spectrometer (7), wherein the sampler (5) is connected to the mass spectrometer (7) and transports the sample to the mass spectrometer (7) for analysis; The data analysis terminal (8) is connected to the mass spectrometer (7) and records, stores and displays the data from the mass spectrometer (7).

2. The mass spectrometer-based monitoring system for the ablation process of heat-resistant materials according to claim 1, characterized in that, It also includes a gas pipeline (6), through which the sampler (5) is connected to the mass spectrometer (7).

3. The mass spectrometer-based monitoring system for the ablation process of heat-resistant materials according to claim 1, characterized in that, The electric arc heater (1) is one of the following: tubular electric arc heater, segmented electric arc heater, stacked electric arc heater or AC electric arc heater.

4. The mass spectrometer-based monitoring system for the ablation process of heat-resistant materials according to claim 1, characterized in that, The nozzle (2) is a Laval nozzle, and is one of an axisymmetric conical nozzle, a rectangular nozzle, or an elliptical nozzle.

5. The mass spectrometer-based monitoring system for the ablation process of heat-resistant materials according to claim 1, characterized in that, The model support (4) is made of thermally conductive metal and has a water-cooling channel.

6. The mass spectrometer-based monitoring system for the ablation process of heat-resistant materials according to claim 1, characterized in that, The experimental model (3) is a flat plate, a stagnation point or a leading edge shape, and its surface is covered with an ablation pyrolysis type heat-resistant material.

7. The mass spectrometer-based monitoring system for the ablation process of heat-resistant materials according to claim 1, characterized in that, The surface of the sampler (5) that comes into contact with the airflow is a natural extension of the surface of the test model (3).

8. The mass spectrometer-based monitoring system for the ablation process of heat-resistant materials according to claim 7, characterized in that, The sampler (5) is a partition structure made of thermally conductive metal, with a gas channel inside and a water cooling channel outside; the sampler (5) has micropores at the top and a metal tube at the bottom.

9. The mass spectrometer-based monitoring system for the ablation process of heat-resistant materials according to claim 2, characterized in that, The gas pipeline (6) is connected in series with a gas filter, and a heat tracing assembly is provided on the gas pipeline (6).

10. The mass spectrometer-based monitoring system for the ablation process of heat-resistant materials according to claim 1, characterized in that, The mass spectrometer (7) is connected and communicates with the data analysis terminal (8) via optical fiber.

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