A temperature field flow field rectification device

Abstract

The invention discloses a temperature field flow field rectifying device, comprising an orifice plate, a stabilizing section and a contraction section; the orifice plate is in the shape of a porous plate, the number of the orifice plates is 2, and the orifice plate is arranged in the stabilizing section; the stabilizing section is composed of a heat-resistant layer, a heat-insulating layer and a metal layer from the inside to the outside, the heat-resistant layer of the stabilizing section is in the shape of a cylinder formed by splicing three sections, the total length of the splicing of the three sections is 3 to 3.5 times of the inner diameter thereof, the first section and the second section sandwich the upstream orifice plate in the middle, the second section and the third section sandwich the downstream orifice plate in the middle, the outer diameter of the heat-resistant layer of the stabilizing section is the same as the diameter of the orifice plate; the contraction section is composed of a heat-resistant layer, a heat-insulating layer and a metal layer from the inside to the outside, the heat-resistant layer of the contraction section is a contracted profile, the inlet diameter is the same as the inner diameter of the heat-resistant layer of the stabilizing section, and the ratio of the inlet cross-sectional area to the outlet cross-sectional area is 15 to 35; the material of the orifice plate, the heat-resistant layer of the stabilizing section and the heat-resistant layer of the contraction section is high-temperature modified ceramic silicon carbide-zirconium boride-hafnium oxide. The invention has good temperature field and flow field qualities while being resistant to high temperatures.

Description

Technical Field

[0001] The invention belongs to the technical field of temperature measurement, and in particular relates to a temperature field flow field rectification device. Background Art

[0002] In the development, production test and use of high-performance aircraft engines, turboramjet combined cycle engines, etc., high airflow temperature is a key test parameter, usually used for engine performance evaluation, status monitoring, combustion diagnosis, etc. High-temperature airflow temperature sensors are used for high-temperature airflow measurement. Due to the existence of various errors such as radiation error, thermal conductivity error, velocity error, and dynamic error, it is necessary to simulate the operating conditions of the temperature sensor in a thermal calibration wind tunnel and calibrate it. In order to ensure the quality of the calibration results, it is hoped that good temperature field and flow field quality can be obtained in the test section of the thermal calibration wind tunnel. For this reason, the usual practice is to set a rectifier in the stable section of the wind tunnel. However, when the airflow temperature reaches above 1500K, it is difficult to find suitable materials to make the rectifier. Generally, the operating temperature of metal materials is below 1500K. Although non-metallic materials such as ceramics can withstand high temperatures, their processability and thermal shock resistance are poor. Some ceramic materials are not resistant to oxidation and cannot meet the use requirements. In summary, the current high-temperature thermal calibration wind tunnels above 1500K cannot obtain ideal temperature field and flow field quality due to the lack of rectifiers. Summary of the invention

[0003] The purpose of the present invention is to provide a temperature field flow field rectifying device which has good temperature field and flow field qualities while being resistant to high temperatures.

[0004] One aspect of the present invention provides a temperature field flow field rectifying device, comprising an orifice plate, a stabilizing section, and a contracting section;

[0005] The orifice plate is in the shape of a porous plate, and the number of the orifice plates is 2, namely an upstream orifice plate and a downstream orifice plate, and the orifice plates are placed in the stable section;

[0006] The stabilizing section comprises, from the inside to the outside, a stabilizing section heat-resistant layer, a stabilizing section heat-insulating layer, and a stabilizing section metal layer. The stabilizing section heat-resistant layer is a cylindrical shape formed by splicing three sections, and the total length of the three sections is 3 to 3.5 times of its inner diameter. The first and second sections of the stabilizing section heat-resistant layer sandwich the upstream orifice plate in the middle, and the second and third sections sandwich the downstream orifice plate in the middle, which are respectively used for axial positioning of the upstream orifice plate and the downstream orifice plate. The outer diameter of the stabilizing section heat-resistant layer is the same as the diameter of the orifice plate.

[0007] The contraction section comprises a contraction section heat-resistant layer, a contraction section heat-insulating layer, and a contraction section metal layer from the inside to the outside, the contraction section heat-resistant layer is a contraction profile, the inlet diameter of the contraction section heat-resistant layer is the same as the inner diameter of the stable section heat-resistant layer, and the ratio of the inlet cross-sectional area to the outlet cross-sectional area of ​​the contraction section heat-resistant layer is 15 to 35;

[0008] The material of the orifice plate, the heat-resistant layer of the stable section and the heat-resistant layer of the contraction section is high-temperature modified ceramic silicon carbide-zirconium boride-hafnium oxide.

[0009] Preferably, the wall thickness of the orifice plate is 20-30 mm, the holes of the orifice plate are round holes with a hole diameter of 10-12 mm, a hole spacing of 2-4 mm, and an opening rate of 60%-65%;

[0010] The axial distance between the upstream orifice plate and the inlet of the stable section is 100-200 mm, and the axial distance between the two orifice plates is 50-100 mm.

[0011] Preferably, the wall thickness of the heat-resistant layer of the stabilizing section is 10 to 15 mm;

[0012] The thickness of the stable section insulation layer is 10 to 200 mm, and the material of the stable section insulation layer is high temperature resistant insulation material;

[0013] The metal layer of the stabilizing section is cylindrical, with a wall thickness of 4 to 15 mm. The material of the metal layer of the stabilizing section is metal or alloy, and the room temperature tensile strength is not less than 500 MPa.

[0014] Preferably, the profile of the heat-resistant layer of the contraction section adopts a Witosinski surface, a bicubic surface or a quintic surface, and the wall thickness of the heat-resistant layer of the contraction section is 10 to 15 mm;

[0015] The thickness of the shrinkage section insulation layer is 10 to 200 mm, and the material of the shrinkage section insulation layer is high temperature resistant insulation material;

[0016] The metal layer of the contraction section is in a conical cylindrical shape, the inlet diameter of the metal layer of the contraction section is the same as the inner diameter of the metal layer of the stable section, the ratio of the inlet diameter to the outlet diameter of the metal layer of the contraction section is 1.5 to 5, the wall thickness is 4 to 15 mm, and the material of the metal layer of the contraction section is metal or alloy, and the room temperature tensile strength is not less than 500 MPa.

[0017] Preferably, the orifice plate, the stable section heat-resistant layer, and the shrinkage section heat-resistant layer are prepared as follows:

[0018] Silicon carbide, zirconium boride and hafnium oxide powders are mixed, wherein the weight percentage of silicon carbide is 70% to 80%, the weight percentage of zirconium boride is 10% to 20%, and the weight percentage of hafnium oxide is 5% to 15%, the mixed powders are added to deionized water, and then 0.1 to 0.5 ppm of acrylamide colloid and 50 to 80 ppm of sodium tripolyphosphate are added, and a slurry is prepared by continuous mechanical stirring or roller ball milling for 1 to 2 hours;

[0019] Slowly inject the slurry into the pre-prepared mold and let it stand for 12 to 24 hours. After the green body solidifies and loses water, open the mold and take out the wet green body.

[0020] The wet blank is placed in a constant temperature and humidity incubator, and is kept at a temperature of ≤40°C and a relative humidity of ≥80% for 48 to 96 hours. After that, the temperature is increased by 3 to 5°C and the relative humidity is decreased by 3% to 5% every 48 hours, and the wet blank is continued to be dried in the constant temperature and humidity incubator for 440 to 480 hours;

[0021] The wet green body is transferred to a blast drying oven and further dried in a blast environment for 48 to 72 hours to obtain a dry green body of a specific shape;

[0022] The dried green body is sintered at a high temperature of 2000℃±10℃ and a vacuum degree better than 1×10 -2 Pa, insulation time 2 to 3 hours.

[0023] Preferably, in the preparation of the orifice plate, after obtaining the dried green body of a specific shape and before sintering the dried green body at a high temperature, the step of grinding the surface of the dried green body to make a round hole is also included.

[0024] The temperature field and flow field rectifying device according to the above aspect of the present invention has good temperature field and flow field qualities while being resistant to high temperatures. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the technical solution of the present invention, the following briefly introduces the drawings used in the description of the embodiments of the present invention. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative work:

[0026] Figure 1 It is a structural schematic diagram of a temperature field flow field rectifying device according to an embodiment of the present invention;

[0027] Figure 2 It is a schematic structural diagram of an orifice plate according to an embodiment of the present invention;

[0028] Figure 3 is a schematic structural diagram of a stabilization segment according to an embodiment of the present invention;

[0029] Figure 4 It is a schematic structural diagram of a contraction section according to an embodiment of the present invention. DETAILED DESCRIPTION

[0030] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be clearly and completely described below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0031] The embodiment of the present invention provides a temperature field flow field rectification device suitable for a high temperature calibration wind tunnel for high temperature calibration of airflow. Figure 1 As shown, the temperature field flow field straightening device according to the embodiment of the present invention includes an orifice plate 1, a stabilizing section 2, and a contraction section 3.

[0032] The orifice plate 1 is in the shape of a porous plate, with a wall thickness of (20-30) mm, circular holes with a hole diameter of (10-12) mm, a hole spacing of (2-4) mm, an opening rate of 60%-65%, and two orifice plates, namely an upstream orifice plate close to the upstream and a downstream orifice plate close to the downstream.

[0033] In one embodiment, Figure 2 As shown, the orifice plate 1 is in the shape of a porous plate, with a diameter of 430 mm, a wall thickness of 20 mm, circular holes, a hole diameter of 10 mm, a hole spacing of 4 mm, an opening rate of 65%, and two orifice plates.

[0034] The orifice plate 1 is placed in the stable section 2, the axial distance between the orifice plate 1 close to the upstream and the inlet of the stable section 2 is (100-200) mm, and the axial distance between the two orifice plates is (50-100) mm.

[0035] In one embodiment, Figure 1 As shown, the orifice plate 1 is placed in the stable section 2, the axial distance between the orifice plate 1 close to the upstream and the inlet of the stable section 2 is 100 mm, and the axial distance between the two orifice plates is 50 mm.

[0036] The material of the orifice plate 1 is high temperature modified ceramic silicon carbide-zirconium boride-hafnium oxide, and the manufacturing method is as follows:

[0037] Step 1: Design and process the orifice plate mold. The shape of the mold complements the orifice plate and the material is gypsum.

[0038] Step 2: Mix silicon carbide, zirconium boride, and hafnium oxide powders, wherein the weight percentage of silicon carbide is 70% to 80%, the weight percentage of zirconium boride is 10% to 20%, and the weight percentage of hafnium oxide is 5% to 15%, add the mixed powders into deionized water, and then add (0.1 to 0.5) ppm of acrylamide colloid, (50 to 80) ppm of sodium tripolyphosphate or other inorganic dispersants, and prepare a slurry by continuous mechanical stirring or roller ball milling for (1 to 2) hours.

[0039] In one embodiment, in step 2, silicon carbide, zirconium boride, and hafnium oxide powders are mixed, wherein the weight percentage of silicon carbide is 80%, the weight percentage of zirconium boride is 12%, and the weight percentage of hafnium oxide is 8%. The mixed powders are added to deionized water, and then 0.3 ppm of acrylamide colloid and 50 ppm of sodium tripolyphosphate are added, and a slurry is prepared by continuous mechanical stirring or roller ball milling for 1 hour.

[0040] Step 3: Slowly inject the slurry into the pre-prepared mold and let it stand for (12 to 24) hours. After the green body solidifies and loses water, open the mold and take out the wet green body.

[0041] In one embodiment, in step three, the slurry is slowly injected into a pre-prepared mold and allowed to stand for 24 hours. After the green body solidifies and loses water, the mold is opened and the wet green body is taken out.

[0042] Step 4: Place the wet blank in a constant temperature and humidity incubator and store it for (48-96) hours in a specific environment with a temperature of ≤40°C and a relative humidity of ≥80%. After that, every 48 hours, the temperature is increased by (3-5)°C and the relative humidity is decreased by 3%-5%, and the wet blank is continued to be dried in the constant temperature and humidity incubator for (440-480) hours.

[0043] In one embodiment, in step 4, the wet blank is placed in a constant temperature and humidity incubator and stored for 48 hours in a specific environment at a temperature of 40° C. and a relative humidity of 80%. Thereafter, the temperature is increased by 5° C. and the relative humidity is decreased by 5% every 48 hours, and the wet blank is dried in the constant temperature and humidity incubator for another 480 hours.

[0044] Step 5: Transfer the wet green body to a blast drying oven and continue drying in a blast environment for (48 to 72) hours to obtain a dry green body of a specific shape.

[0045] In one embodiment, in step five, the wet green body is transferred to a forced air drying oven and further dried for 48 hours in a forced air environment to obtain a dry green body of a specific shape.

[0046] Step 6: Grind the surface of the dried green body to make it smooth and grind out a round hole.

[0047] Step 7: Sinter the dried green body at high temperature, the sintering temperature is 2000℃±10℃, and the vacuum degree is better than 1×10 - 2 Pa, insulation time (2-3) hours.

[0048] In one embodiment, in step seven, the dried green body is subjected to high temperature sintering, the sintering temperature is 2000° C., the vacuum degree is 0.9×10 -2Pa, holding time 2 hours.

[0049] like Figure 3 As shown, the stabilizing section 2 comprises, from the inside to the outside, a stabilizing section heat-resistant layer 4, a stabilizing section heat-insulating layer 5, and a stabilizing section metal layer 6.

[0050] The heat-resistant layer of the stabilizing section is a cylindrical shape of three sections spliced ​​together, with an outer diameter the same as the diameter of the orifice plate, a wall thickness of (10-15) mm, and a total length of the three sections spliced ​​together that is (3-3.5) times its inner diameter. In one embodiment, the heat-resistant layer of the stabilizing section 4 is a cylindrical shape of three sections spliced ​​together, with an outer diameter of 430 mm, a wall thickness of 15 mm, and a total length of the three sections spliced ​​together that is 1200 mm.

[0051] The first and second sections of the stable section heat-resistant layer 4 sandwich the upstream orifice plate in the middle, and the second and third sections sandwich the downstream orifice plate in the middle, which are used for axial positioning of the upstream orifice plate and the downstream orifice plate respectively; the manufacturing method of the stable section heat-resistant layer 4 refers to steps 1 to 5 and 7 in the orifice plate manufacturing method.

[0052] The thickness of the stable section insulation layer 5 is (10-200) mm, and the material can be high temperature resistant insulation cotton, or other high temperature resistant insulation materials. In one embodiment, the thickness of the stable section insulation layer 5 is 180 mm, and the material is zirconia insulation cotton.

[0053] The stabilizing section metal layer 6 is cylindrical, with a wall thickness of (4-15) mm, and can be made of stainless steel, or other metals or alloys, with a room temperature tensile strength of not less than 500 MPa. In one embodiment, the stabilizing section metal layer 6 is cylindrical, with a wall thickness of 7 mm, and is made of 316 stainless steel.

[0054] like Figure 4 As shown, the contraction section 3 comprises, from the inside to the outside, a contraction section heat-resistant layer 7, a contraction section heat-insulating layer 8, and a contraction section metal layer 9.

[0055] The shrinking section heat-resistant layer 7 is a shrinking profile, and the profile adopts a Witosinski surface, a bicubic surface or a quintic surface. The inlet diameter is the same as the inner diameter of the stable section heat-resistant layer, the ratio of the inlet cross-sectional area to the outlet cross-sectional area is 15 to 35, and the wall thickness is (10 to 15) mm. In one embodiment, the shrinking section heat-resistant layer 7 is a shrinking profile, and the profile adopts a Witosinski surface, the inlet diameter is 400 mm, the outlet diameter is 100 mm, and the wall thickness is 15 mm. The manufacturing method of the shrinking section heat-resistant layer 7 refers to steps 1 to 5 and 7 in the orifice plate manufacturing method.

[0056] The thickness of the shrinkage section insulation layer 8 is (10-200) mm, and the material can be high temperature resistant insulation cotton, or other high temperature resistant insulation materials. In one embodiment, the thickness of the shrinkage section insulation layer 8 is 180 mm, and the material is zirconia insulation cotton.

[0057] The metal layer 9 of the contraction section is in the shape of a cone, the inlet diameter is the same as the inner diameter of the metal layer of the stable section, the ratio of the inlet diameter to the outlet diameter is 1.5-5, the wall thickness is (4-15) mm, the material can be stainless steel, or other metals or alloys, and the room temperature tensile strength is not less than 500 MPa. In one embodiment, the metal layer 9 of the contraction section is in the shape of a cone, the inlet diameter is 790 mm, the outlet diameter is 490 mm, the wall thickness is 7 mm, and the material is 316 stainless steel.

[0058] The temperature field flow field rectifying device of the embodiment of the present invention is a temperature field flow field rectifying device based on high temperature modified ceramics, which has the following beneficial effects:

[0059] 1. In order to solve the problem of poor quality of temperature field and flow field in the current high-temperature thermal calibration wind tunnel above 1500K, the present invention uses multiphase ceramic silicon carbide-zirconium boride-hafnium oxide as the orifice plate and heat-resistant layer material, and through modification of zirconium boride and hafnium oxide, the upper limit of the use temperature can reach 2300K, avoiding the problem that pure silicon carbide cannot be used due to low use temperature. At the same time, combined with a stable section with a large aspect ratio and a contraction section with a large contraction ratio, it has the advantages of good temperature field and flow field quality while being resistant to high temperature.

[0060] 2. In the orifice plate and heat-resistant layer materials, the main function of zirconium boride is to use its own high melting point to increase the upper limit of the use temperature, and the main function of hafnium oxide is to increase the upper limit of the use temperature and reduce the ablation rate of the material. The role of adding acrylamide colloid is to bond, increase the bonding force between silicon carbide, zirconium boride and hafnium oxide, and ensure the basic strength of the material. The role of adding inorganic dispersants such as sodium tripolyphosphate is to increase the activity of silicon carbide, zirconium boride and hafnium oxide materials, prevent them from uneven aggregation, and ensure the uniformity of material performance.

[0061] 3. After a large number of tests and analyses, the present invention has found that when the aspect ratio of the stable section is 3 to 3.5 and the contraction ratio of the contraction section is 15 to 35, the high-temperature airflow can be further effectively combed, which can further improve the temperature field and flow field quality of the test section.

[0062] The above description is only by way of illustration of certain exemplary embodiments of the present invention. It is undoubted that those skilled in the art can modify the described embodiments in various ways without departing from the spirit and scope of the present invention. Therefore, the above drawings and descriptions are illustrative in nature and should not be construed as limiting the scope of protection of the claims of the present invention.

Claims

1. A temperature field flow field rectifying device, characterized in that: It includes orifice plate, stable section and contraction section; The orifice plate is in the shape of a porous plate, and the number of the orifice plates is 2, namely an upstream orifice plate and a downstream orifice plate, and the orifice plates are placed in the stable section; The stabilizing section comprises, from the inside to the outside, a stabilizing section heat-resistant layer, a stabilizing section heat-insulating layer, and a stabilizing section metal layer. The stabilizing section heat-resistant layer is a cylindrical shape formed by splicing three sections, and the total length of the three sections is 3 to 3.5 times of its inner diameter. The first and second sections of the stabilizing section heat-resistant layer sandwich the upstream orifice plate in the middle, and the second and third sections sandwich the downstream orifice plate in the middle, which are respectively used for axial positioning of the upstream orifice plate and the downstream orifice plate. The outer diameter of the stabilizing section heat-resistant layer is the same as the diameter of the orifice plate. The contraction section comprises a contraction section heat-resistant layer, a contraction section heat-insulating layer, and a contraction section metal layer from the inside to the outside, the contraction section heat-resistant layer is a contraction profile, the inlet diameter of the contraction section heat-resistant layer is the same as the inner diameter of the stable section heat-resistant layer, and the ratio of the inlet cross-sectional area to the outlet cross-sectional area of ​​the contraction section heat-resistant layer is 15 to 35; The material of the orifice plate, the heat-resistant layer of the stable section and the heat-resistant layer of the contraction section is high-temperature modified ceramic silicon carbide-zirconium boride-hafnium oxide; The orifice plate, the stable section heat-resistant layer, and the shrinkage section heat-resistant layer are prepared as follows: Silicon carbide, zirconium boride and hafnium oxide powders are mixed, wherein the weight percentage of silicon carbide is 70% to 80%, the weight percentage of zirconium boride is 10% to 20%, and the weight percentage of hafnium oxide is 5% to 15%, the mixed powders are added to deionized water, and then 0.1 to 0.5 ppm of acrylamide colloid and 50 to 80 ppm of sodium tripolyphosphate are added, and a slurry is prepared by continuous mechanical stirring or roller ball milling for 1 to 2 hours; Slowly inject the slurry into the pre-prepared mold and let it stand for 12 to 24 hours. After the green body solidifies and loses water, open the mold and take out the wet green body. The wet blank is placed in a constant temperature and humidity incubator, and is kept at a temperature of ≤40°C and a relative humidity of ≥80% for 48 to 96 hours. After that, the temperature is increased by 3 to 5°C and the relative humidity is decreased by 3% to 5% every 48 hours, and the wet blank is continued to be dried in the constant temperature and humidity incubator for 440 to 480 hours; The wet green body is transferred to a blast drying oven and further dried in a blast environment for 48 to 72 hours to obtain a dry green body of a specific shape; The dried green body is sintered at a high temperature of 2000℃±10℃ and a vacuum degree better than 1×10 -2 Pa, insulation time 2 to 3 hours.

2. The warm field flow field rectifying device according to claim 1, characterized in that: The wall thickness of the orifice plate is 20-30 mm, the holes of the orifice plate are round holes with a hole diameter of 10-12 mm, a hole spacing of 2-4 mm, and an opening rate of 60%-65%; The axial distance between the upstream orifice plate and the inlet of the stable section is 100-200 mm, and the axial distance between the two orifice plates is 50-100 mm.

3. The warm field flow field rectifying device according to claim 1 or 2, characterized in that: The wall thickness of the heat-resistant layer of the stabilizing section is 10 to 15 mm; The thickness of the stable section insulation layer is 10 to 200 mm, and the material of the stable section insulation layer is high temperature resistant insulation material; The metal layer of the stabilizing section is cylindrical, with a wall thickness of 4 to 15 mm. The material of the metal layer of the stabilizing section is metal or alloy, and the room temperature tensile strength is not less than 500 MPa.

4. The warm field flow field rectifying device according to claim 1 or 2, characterized in that: The profile of the heat-resistant layer of the shrinkage section adopts a Witosinski surface, a bicubic surface or a quintic surface, and the wall thickness of the heat-resistant layer of the shrinkage section is 10 to 15 mm; The thickness of the shrinkage section insulation layer is 10 to 200 mm, and the material of the shrinkage section insulation layer is high temperature resistant insulation material; The metal layer of the contraction section is in a conical cylindrical shape, the inlet diameter of the metal layer of the contraction section is the same as the inner diameter of the metal layer of the stable section, the ratio of the inlet diameter to the outlet diameter of the metal layer of the contraction section is 1.5 to 5, the wall thickness is 4 to 15 mm, and the material of the metal layer of the contraction section is metal or alloy, and the room temperature tensile strength is not less than 500 MPa.

5. The warm field flow field rectifying device according to claim 1 or 2, characterized in that: In the preparation of the orifice plate, after obtaining the dry green body of a specific shape and before sintering the dry green body at a high temperature, the step of grinding the surface of the dry green body to make the circular hole is also included.

Images