Method for preparing simulated bird bomb for aviation engine bird strike test

Abstract

The present application belongs to the field of aircraft engine bird strike test design, and is a method for preparing simulated birdshot for aircraft engine bird strike test. The method comprises the following steps: first, preparing materials and tools, and then pouring gelatin and water into a stainless steel barrel according to a set ratio, stirring the gelatin and water with a stirring rod, and forming a gelatin mixture after uniform stirring at room temperature. The gelatin mixture is placed in a constant temperature water tank and allowed to stand and melt to complete the preparation of the gelatin mixture; the gelatin mixture adopts a ratio of 78:22, of which 78% is water and 22% is gelatin. When preparing the gelatin mixture, a specified weight of water is first poured into the stainless steel barrel, and while stirring the water in the stainless steel barrel with a stirring rod, gelatin powder is poured into the water, and the mixing time of the gelatin mixture is no more than 5 minutes; the gelatin mixture is stirred for 10 minutes at a medium speed of a blender; and then the preparation of the simulated birdshot is completed through injection molding, curing, and demolding; the manufacturing efficiency is high, the stability is high, and the manufacturing cost is low.

Description

Technical Field

[0001] The present application relates to the field of aircraft engine bird strike test design, and in particular to a method for preparing a simulated bird bomb for aircraft engine bird strike test. Background Art

[0002] During the development process, aircraft engines undergo a series of assessment tests to verify their airworthiness. Bird strike tests, among other things, can verify an engine's bird-swallowing capability. Therefore, before the complete engine bird-swallowing test, a series of component-level bird strike tests are conducted to verify the engine's fan components' bird-strike resistance.

[0003] Due to the diverse types and widely varying shapes of real birds, as well as the difficulty in controlling the strength and stability of the birds themselves, conducting large-scale bird strike tests on components using real birds presents significant challenges in controlling test parameters and understanding the damage patterns of fan components. Therefore, using simulated bird projectiles for bird strike testing of aircraft engine components is beneficial for improving the stability of bird projectile performance, increasing the efficiency of component bird strike testing, and shortening the aircraft engine development cycle.

[0004] Simulated birdshot is a projectile structure used in bird strike tests on aircraft engine components to impact target test pieces. It is used to replace real birdshot and has the characteristics of controllable structural design, high mass precision, stable projection posture, and high projection accuracy. Commonly used simulated birdshot cross-sectional shapes are as follows: Figure 1 As shown, the cross-sectional dimensions of simulated birdshot require a length-to-diameter ratio (L:D) of 2:1.

[0005] like Figure 2 As shown, the left side shows the rotating engine components, the right side shows the simulated birdshot, and between them are structures such as a high-speed camera, springs, ejectors, and sealing rings. The simulated birdshot is mounted in a sabot and moves at high speed with it during launch. When the sabot propels the simulated birdshot to the ejector at the muzzle of the gun, it is stopped by the ejector, causing the sabot's movement to abruptly stop. The simulated birdshot continues its flight, achieving separation between the sabot and the simulated birdshot. The simulated birdshot continues its high-speed flight until it impacts the rotating engine components.

[0006] 1. Technical aspects

[0007] According to Article 33.76 of my country's aviation engine airworthiness standards, the weight requirements for different bird bombs are: the mass requirement for large birds is above 1.85kg, and the mass requirement for small and medium birds is between 0.35 and 1.15kg.

[0008] Gelatin material has relatively balanced capabilities in strength and bionics, which can ensure that the simulated birdshot maintains its complete structure when flying at high speed, while its bionic performance is close to that of real birdshot.

[0009] The shortcoming is that the traditional process uses water, gelatin powder, chemical additives, etc. as raw materials to prepare simulated bird bombs. The generation of bubbles inside the simulated bird bombs is controlled by chemical reactions. The process is greatly affected by environmental factors, and the performance parameters of simulated bird bombs prepared in different batches are unstable.

[0010] 2. Cost

[0011] Component bird strike testing requires multiple speed adjustments before each formal test to verify the stability of the firing velocity. To improve the stability of the performance parameters of the simulated birdshot used in the tests, large numbers of simulated birdshots must be produced in the same batch. Selected simulated birdshots with similar performance are used for speed adjustments and formal testing, resulting in high production costs for component bird strike testing.

[0012] 3. Efficiency

[0013] At present, the process of preparing gelatin birdshot is long. If the gelatin mixture adopts the freezing and solidification process method, the thawing cycle is long and the uniform thawing process is difficult to achieve. The scrap rate of the prepared simulated birdshot is high, which affects the efficiency of the test work. If the refrigeration and solidification process method is adopted, the traditional process refrigeration time does not take into account the influence of the weight of the simulated birdshot, resulting in insufficient solidification time of the simulated birdshot, and the strength of the simulated birdshot is relatively soft, which cannot represent the real bird body, which also leads to a high scrap rate of the simulated birdshot and affects the efficiency of the test work.

[0014] Therefore, how to improve the manufacturing efficiency and stability of simulated birdshot and reduce manufacturing costs is a problem that needs to be solved. Summary of the Invention

[0015] The purpose of this application is to provide a method for preparing simulated birdshot for aircraft engine bird strike tests, so as to solve the problems of high manufacturing cost, unstable parameters and low manufacturing efficiency of simulated birdshot in the prior art.

[0016] The technical solution of the present application is: a method for preparing a simulated birdshot for an aircraft engine bird strike test, comprising:

[0017] Determine the applicable scope of the preparation process for simulated birdshot, and accurately determine the materials and tools within the applicable scope of the preparation process. The materials include gelatin, food additives, and industrial tap water. The tools used include stainless steel buckets, stirring rods, constant temperature water tanks, blenders, molds, refrigerators, and electronic balances.

[0018] Pour gelatin and water into a stainless steel barrel according to a set ratio, stir the gelatin and water with a stirring rod, and form a gelatin mixture after stirring evenly at room temperature. Place the gelatin mixture into a constant temperature water tank and let it stand to melt to complete the preparation of the gelatin mixture. The gelatin mixture adopts a ratio of 78:22, of which 78% is water and 22% is gelatin. When preparing the gelatin mixture, first pour a specified weight of water into the stainless steel barrel, and while stirring the water in the stainless steel barrel with a stirring rod, pour the gelatin powder into the water. The gelatin mixture is mixed for no more than 5 minutes.

[0019] Blend the gelatin mixture in a blender at medium speed for 10 minutes;

[0020] After the stirring is completed, the gelatin mixture is injected into the mold, and the mold containing the gelatin mixture is placed in the refrigerator. After refrigeration for a certain period of time, the simulated birdshot is completed. The prepared simulated birdshot is demolded and placed on an electronic balance for weighing.

[0021] Preferably, the target temperature of the constant temperature water tank is set to 35°C, and the preparation of the gelatin mixture is started after the measured temperature of the constant temperature water tank reaches 35°C±1°C. A thermometer is set in the constant temperature water tank to monitor and record the temperature of the gelatin mixture.

[0022] Preferably, the preparation process of the simulated bird shot is applicable to the following ranges: the total mass of the simulated bird shot is not more than 2.75 kg, and the density range of the simulated bird shot is: 0.94 g / cm 3 ~0.96g / cm 3 .

[0023] Preferably, the gelatin mixture is allowed to stand in the constant temperature water tank for 22-24 hours, and is stirred by a stirring rod when the gelatin mixture is cooled to a temperature within the range of 24°C to 25°C. After the standing time is completed, the target temperature in the constant temperature water tank is set to 17°C.

[0024] Preferably, the mid-range speed of the mixer is 1200 r / min to 1400 r / min.

[0025] Preferably, the injection molding process of the mold is no more than 3 minutes, the ambient temperature of the gelatin mixture in the refrigerator is 3° C. to 6° C., the temperature in the refrigerator is recorded in real time by a temperature sensor, the simulated birdshot is prepared after curing in the refrigerator for 24 hours, and the simulated birdshot is demolded and taken out after being stored in the refrigerator for 6 hours after preparation.

[0026] The present application discloses a method for preparing a simulated birdshot for an aircraft engine bird strike test. The method comprises the following steps: after determining the applicable scope of the preparation process of the simulated birdshot, preparing materials and tools, and then pouring gelatin and water into a stainless steel barrel according to a set ratio. The gelatin and water are stirred with a stirring rod, and after being stirred evenly at room temperature, a gelatin mixture is formed. The gelatin mixture is placed in a constant temperature water tank and allowed to stand and melt to complete the preparation of the gelatin mixture. The gelatin mixture adopts a ratio of 78:22, wherein 78% is water and 22% is gelatin. When preparing the gelatin mixture, a specified weight of water is first poured into the stainless steel barrel. While stirring the water in the stainless steel barrel with a stirring rod, gelatin powder is poured into the water. The mixing time of the gelatin mixture is no more than 5 minutes. The gelatin mixture is stirred at a medium speed of a blender for 10 minutes. The preparation of the simulated birdshot is then completed through injection molding, curing, and demolding. The method has high manufacturing efficiency, high stability, and low manufacturing cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the technical solutions provided by this application, the following is a brief introduction to the accompanying drawings. Obviously, the accompanying drawings described below are only some embodiments of this application.

[0028] Figure 1 A schematic diagram of the cross-sectional shape of a simulated birdshot in the background art;

[0029] Figure 2 Schematic diagram of the component-level fan bird strike test structure in the background technology;

[0030] Figure 3 This is a schematic diagram of the overall process of this application. DETAILED DESCRIPTION

[0031] In order to make the purpose, technical solutions and advantages of the implementation of this application clearer, the technical solutions in the embodiments of this application will be described in more detail below in conjunction with the drawings in the embodiments of this application.

[0032] A method for preparing a simulated bird bomb for an aircraft engine bird strike test, such as Figure 2 As shown, the following steps are included:

[0033] Step S100, determining the applicable scope of the preparation process of the simulated birdshot, accurately selecting materials and tools within the applicable scope of the preparation process, the materials including gelatin, food additives and industrial tap water, the food additive (cowhide) is a spare gelatin raw material, and the product standard is implemented in accordance with GB6783-2013.

[0034] The tools used include stainless steel buckets, stirring rods, constant temperature water tanks, blenders, molds, refrigerator freezers, and electronic balances;

[0035] a) Stainless steel barrel: used for preparing gelatin mixture, made of food-grade 304 stainless steel;

[0036] b) Stirring rod: used to prepare gelatin mixture;

[0037] c) Constant temperature water tank: provides a constant temperature water environment for the stainless steel barrel containing the gelatin mixture during the preparation of simulated birdshot, and is equipped with a heating unit, a cooling unit, a temperature measurement and control module, and a water circulation system;

[0038] d) Thermometer: used to monitor and record the temperature of the gelatin mixture;

[0039] e) Blender: A blender equipped with stainless steel paddles is used to inflate the gelatin mixture with air, so that the prepared simulated birdshot has biomimetic properties close to those of a real bird;

[0040] f) Mold: used to solidify the gelatin mixture and ensure that the simulated birdshot shape meets the test requirements;

[0041] g) Refrigerator: used to provide a constant temperature environment for the solidification process of the gelatin mixture.

[0042] h) Electronic balance: used to weigh the simulated birdshot after demoulding and calculate the density of the simulated birdshot.

[0043] The preparation process range of simulated birdshot is shown in Table 1:

[0044] Table 1 Applicable scope of preparation process

[0045]

[0046] Note: The total mass of simulated birdshot refers to the total mass of effective simulated birdshot produced in one batch production. For example, for a single simulated birdshot with a mass requirement of 0.6 kg, the number of simulated birdshot that can be produced in one batch production is 4; for a single simulated birdshot with a mass requirement of 0.35 kg, the number of simulated birdshot that can be produced in one batch production is 7.

[0047] Step S200: Pour gelatin and water into a stainless steel barrel according to a set ratio, stir the gelatin and water with a stirring rod, and form a gelatin mixture after stirring at room temperature. Place the gelatin mixture in a constant temperature water tank and let it stand and melt, thereby completing the preparation of the gelatin mixture;

[0048] Preferably, the target temperature of the constant temperature water tank is set to 35°C, and the preparation of the gelatin mixture is started after the measured temperature of the constant temperature water tank reaches 35°C±1°C. A thermometer is set in the constant temperature water tank to monitor and record the temperature of the gelatin mixture.

[0049] The gelatin mixture is prepared in a ratio of 78:22, wherein 78% is water and 22% is gelatin. When preparing the gelatin mixture, first pour a specified weight of water into a stainless steel barrel, and while stirring the water in the stainless steel barrel with a stirring rod, pour the gelatin powder into the water. The gelatin mixture is mixed for no more than 5 minutes.

[0050] Gelatin materials produced in accordance with the GB6783-2013 product standard have the best solubility characteristics in water at 35°C.

[0051] The simulated bird bullet prepared by using gelatin mixture in a ratio of 78:22 has bionic properties close to those of a real bird.

[0052] First, pour water into a stainless steel bucket, then pour in gelatin powder while stirring with a stirring rod. Complete the mixing process of gelatin and water within 5 minutes. This can effectively avoid the formation of unnecessary lumps in the gelatin mixture, which will affect the production effect of simulated birdshot.

[0053] The amount of time the gelatin mixture needs to stand and melt varies depending on the weight of the simulated birdshot being prepared. For simulated birdshot weighing no more than 2.75 kg, the gelatin mixture should be allowed to stand for 22 to 24 hours to allow the gelatin and water to fully dissolve.

[0054] The gelatin mixture is allowed to stand in the constant temperature water tank for 22-24 hours. When the gelatin mixture is cooled to a temperature within the range of 24°C to 25°C, it is stirred by a stirring rod. After the standing time is completed, the target temperature in the constant temperature water tank is set to 17°C.

[0055] The gelatin mixture has the best bubble incorporation properties at 24℃~25℃: if the temperature is too high, the introduced bubbles cannot stay in the gelatin mixture; if the temperature is too low, the gelatin mixture begins to form a crust on the surface, the liquid begins to become thick, and it is difficult to introduce bubbles.

[0056] Step S300, recording the ambient temperature with a thermometer, stirring the gelatin mixture in a constant temperature water tank with a blender at a medium speed (1200 rpm to 1400 rpm) for 10 minutes;

[0057] The blender's paddles stir the gelatin mixture at a temperature of 24-25°C, causing air to enter the mixture as bubbles. After stirring at medium speed for 10 minutes, the resulting simulated birdshot possesses biomimetic properties close to those of a real bird.

[0058] In step S400, after the stirring is completed, the gelatin mixture is injected into the mold, and the mold containing the gelatin mixture is placed in the refrigerator. After refrigeration for a certain period of time, the simulated birdshot is prepared. The prepared simulated birdshot is demolded and placed on an electronic balance for weighing.

[0059] Preferably, the injection molding process of the mold is no more than 3 minutes, the ambient temperature of the gelatin mixture in the refrigerator is 3° C. to 6° C., the temperature in the refrigerator is recorded in real time by a temperature sensor, the simulated birdshot is prepared after curing in the refrigerator for 24 hours, and the simulated birdshot is demolded and taken out after being stored in the refrigerator for 6 hours after preparation.

[0060] Immediately after the stirring is completed, the injection molding process of the gelatin mixture is started, and the injection molding process should not exceed 3 minutes to avoid the influence of the ambient temperature and the loss of bubbles caused by the increase in temperature of the gelatin mixture.

[0061] The gelatin mixture solidifies in a refrigerator at 3°C ​​to 6°C. If the freeze-curing method is used, it must be thawed before use. The uneven thawing process from the outside in will cause the ice-water mixture inside to become loose, which will cause the simulated birdshot to have a loose interface.

[0062] The simulated bird bullet needs 24 hours to cure in the mold. If the curing time is too short, the simulated bird bullet will be too soft and cannot represent the bionic performance of a real bird.

[0063] The finished simulated bird bullet can be kept in the mold for 6 hours. If it is kept for too long, it will lose moisture, harden the surface, and increase its brittleness. It also cannot represent the bionic performance of a real bird.

[0064] After determining the applicable scope of the preparation process of simulated birdshot, the present application prepares materials and tools, and then pours gelatin and water into a stainless steel barrel according to a set ratio, stirs the gelatin and water with a stirring rod, and forms a gelatin mixture after stirring evenly at room temperature. The gelatin mixture is placed in a constant temperature water tank and allowed to stand and melt to complete the preparation of the gelatin mixture; the gelatin mixture adopts a ratio of 78:22, of which 78% is water and 22% is gelatin. When preparing the gelatin mixture, a specified weight of water is first poured into the stainless steel barrel, and while stirring the water in the stainless steel barrel with a stirring rod, gelatin powder is poured into the water. The gelatin mixture is mixed for no more than 5 minutes; the gelatin mixture is stirred for 10 minutes at a medium speed of the blender;

[0065] The simulated birdshot is then prepared through injection molding, curing, and demolding. By identifying key parameters in the simulated birdshot preparation process, the preparation process is quantitatively controlled, improving the performance stability of batch-produced simulated birdshot and resolving the issue of unstable performance parameters between batches of simulated birdshot in existing preparation methods. The prepared simulated birdshot is accurate in weight and does not require large-scale production, addressing the high cost of preparing simulated birdshot for component bird strike tests. Furthermore, a curing process is proposed, and the shelf life of the simulated birdshot in the mold is identified, addressing the high scrap rate in existing simulated birdshot preparation methods.

[0066] The above description is merely a specific embodiment of the present application, but the scope of protection of the present application is not limited thereto. Any changes or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in this application should be included in the scope of protection of the present application. Therefore, the scope of protection of the present application should be based on the scope of protection of the claims.

Claims

1. A method for preparing a simulated bird bomb for an aircraft engine bird strike test, characterized in that: include: Determine the applicable scope of the preparation process for simulated birdshot, and accurately determine the materials and tools within the applicable scope of the preparation process. The materials include gelatin, food additives, and industrial tap water. The tools used include stainless steel buckets, stirring rods, constant temperature water tanks, blenders, molds, refrigerators, and electronic balances. Pour gelatin and water into a stainless steel barrel according to a set ratio, stir the gelatin and water with a stirring rod, and form a gelatin mixture after stirring evenly at room temperature. Place the gelatin mixture into a constant temperature water tank and let it stand to melt to complete the preparation of the gelatin mixture. The gelatin mixture adopts a ratio of 78:22, of which 78% is water and 22% is gelatin. When preparing the gelatin mixture, first pour a specified weight of water into the stainless steel barrel, and while stirring the water in the stainless steel barrel with a stirring rod, pour the gelatin powder into the water. The gelatin mixture is mixed for no more than 5 minutes. Blend the gelatin mixture in a blender at medium speed for 10 minutes; After the stirring is completed, the gelatin mixture is injected into a mold, and the mold containing the gelatin mixture is placed in a refrigerator. After being refrigerated for a certain period of time, the simulated birdshot is prepared. The prepared simulated birdshot is demolded and placed on an electronic balance for weighing. Set the target temperature of the constant temperature water tank to 35°C. When the measured temperature of the constant temperature water tank reaches 35°C ± 1°C, start preparing the gelatin mixture. Set a thermometer in the constant temperature water tank to monitor and record the temperature of the gelatin mixture. The gelatin mixture is allowed to stand in the constant temperature water tank for 22-24 hours, and is stirred by a stirring rod when the gelatin mixture is cooled to a temperature within the range of 24°C to 25°C. After the standing time is completed, the target temperature in the constant temperature water tank is set to 17°C.

2. The method for preparing a simulated bird bomb for an aircraft engine bird strike test according to claim 1, wherein: The preparation process of the simulated bird shot is applicable to the following ranges: the total mass of the simulated bird shot is not more than 2.75 kg, and the density range of the simulated bird shot is: 0.94 g / cm 3 ~0.96g / cm 3 .

3. The method for preparing a simulated birdshot for an aircraft engine bird strike test according to claim 1, wherein: The mid-range speed of the mixer is 1200 r / min to 1400 r / min.

4. The method for preparing a simulated birdshot for an aircraft engine bird strike test according to claim 1, wherein: The injection molding process takes no more than 3 minutes, the ambient temperature of the gelatin mixture in the refrigerator is 3°C to 6°C, and the temperature in the refrigerator is recorded in real time by a temperature sensor. The simulated birdshot is prepared after being solidified in the refrigerator for 24 hours. After the preparation of the simulated birdshot is completed, it is stored in the refrigerator for 6 hours and then demolded and taken out.

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