Method for determining radar stealth performance of aero-engine radar stealth material after damage

Abstract

The application relates to a method for determining the radar stealth performance of an aero-engine after damage of radar stealth materials. On the basis of setting different damage areas of the radar stealth materials on each component, simulation calculation is adopted to obtain the radar stealth performance of the aero-engine under different damage area combinations of the radar stealth materials on each component, a regression equation for correlating the radar stealth performance of the aero-engine and the damage areas of the radar stealth materials on each component is trained, regression coefficients are obtained, an aero-engine is selected, the damage areas of each component are measured, the radar stealth performance is obtained through simulation calculation, the accuracy of the regression equation is tested, and after the test is passed, the radar stealth performance of the target aero-engine is rapidly calculated, so that the demand for rapidly determining the radar stealth performance of the aero-engine in practice can be met.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of determining the radar stealth performance of an aero-engine based on the state of a stealth material, and particularly relates to a method for determining the radar stealth performance of an aero-engine after damage to a radar stealth material. BACKGROUND

[0002] The radar characteristic signal of an aero-engine is an important component of the total radar characteristic signal of an aircraft. In order to improve the radar stealth performance of an aero-engine, low-emissivity radar stealth materials are coated on the surfaces of some components.

[0003] With the increase in the working time of an aero-engine, the radar stealth materials on the components may be damaged by local peeling off and scratching, thereby reducing the radar stealth performance of the aero-engine.

[0004] After the radar stealth materials on the components of an aero-engine are damaged, the radar stealth performance of the aero-engine needs to be determined again to determine whether maintenance is needed. At present, special-purpose calculation software is used to carry out three-dimensional numerical simulation on the geometric model of the aero-engine, and the radar stealth performance of the aero-engine is obtained by simulation calculation. This technical solution requires highly professional personnel to perform the calculation, and it takes a long time, which cannot meet the demand for quickly determining the radar stealth performance of an aero-engine.

[0005] The present application is proposed in view of the above technical defects.

[0006] It should be noted that the disclosure of the above background art is only used to assist in understanding the inventive concept and technical solutions of the present application, and it does not necessarily belong to the prior art of the present application. In the absence of explicit evidence that the above content has been disclosed on the filing date of the present application, the above background art should not be used to evaluate the novelty and inventiveness of the present application. SUMMARY

[0007] The purpose of the present application is to provide a method for determining the radar stealth performance of an aero-engine after damage to a radar stealth material, so as to overcome or alleviate at least one aspect of the known technical defects.

[0008] The technical solution of the present application is as follows:

[0009] A method for determining the radar stealth performance of an aero-engine after damage to a radar stealth material, comprising:

[0010] n different damage areas of the radar stealth material on each component are set;

[0011] The radar stealth performance of the aero-engine under different combinations of damage areas of the radar stealth material on each component is obtained by simulation calculation;

[0012] a regression equation between the radar stealth performance of the aero-engine and the damage area of the radar stealth material on each component is constructed;

[0013] The regression equation is trained by using the radar stealth performance of the aero-engine under different combinations of the damage area of the radar stealth material on each component, and regression coefficients are obtained;

[0014] An aero-engine is selected, the damage area of each component of the aero-engine is measured, the radar stealth performance of the aero-engine is obtained by simulation calculation, and the radar stealth performance of the aero-engine is calculated by using the regression equation, so as to test the accuracy of the regression equation, if the test fails, the value of n is increased, and the regression coefficients are obtained again;

[0015] The damage area of each component of the target aero-engine is measured, and the radar stealth performance of the target aero-engine is calculated by using the regression equation.

[0016] According to at least one embodiment of the present application, in the above-mentioned method for determining the radar stealth performance of the aero-engine after the radar stealth material is damaged, the radar stealth material on each component is set to have n different damage areas, specifically:

[0017]

[0018] wherein,

[0019] is the nth damage area of the radar stealth material on the ith component;

[0020] γ is a damage conversion coefficient of the radar stealth material on the component, which is close to n in value;

[0021] S i is the area of the radar stealth material on the ith backward visible component.

[0022] According to at least one embodiment of the present application, in the above-mentioned method for determining the radar stealth performance of the aero-engine after the radar stealth material is damaged, γ = 1.05n.

[0023] According to at least one embodiment of the present application, in the above-mentioned method for determining the radar stealth performance of the aero-engine after the radar stealth material is damaged, the components include low-vortex secondary blades, components of afterburning chambers, and nozzle expansion sections.

[0024] According to at least one embodiment of the present application, in the above-mentioned method for determining the radar stealth performance of the aero-engine after the radar stealth material is damaged, the regression equation between the radar stealth performance of the aero-engine and the damage area of the radar stealth material on each component is constructed, specifically:

[0025]

[0026] wherein,

[0027] I radar stealth performance of an aero-engine;

[0028] is the damage area of the radar stealth material on the ith component;

[0029] β0, β1, β2, …, β i is a regression coefficient.

[0030] According to at least one embodiment of the present application, in the method for determining the radar stealth performance of the radar stealth material of the aero-engine after damage described above, when the absolute value of the difference between the actual value and the calculated value is greater than 5%, the test fails. 仿 -I 预 | / I 仿 ×100%>5%, the test fails.

[0031] According to at least one embodiment of the present application, in the method for determining the radar stealth performance of the radar stealth material of the aero-engine after damage described above, when the radar stealth performance of the aero-engine under different combinations of damage areas of the radar stealth material on each component is used to train the regression equation and obtain the regression coefficient, the least square method is used to estimate the regression coefficient.

[0032] The present application has at least the following beneficial technical effects:

[0033] The present application provides a method for determining the radar stealth performance of the radar stealth material of an aero-engine after damage. On the basis of setting multiple different damage areas of the radar stealth material on each component, simulation calculation is used to obtain the radar stealth performance of the aero-engine under different combinations of damage areas of the radar stealth material on each component. The regression equation related to the radar stealth performance of the aero-engine and the damage area of the radar stealth material on each component is trained, and the regression coefficient is obtained. An aero-engine is selected, the damage areas of each component are measured, the radar stealth performance is obtained by simulation calculation, and the accuracy of the regression equation is tested. After the test passes, the radar stealth performance of the target aero-engine is quickly calculated, which can meet the demand for quickly determining the radar stealth performance of the aero-engine in practice. BRIEF DESCRIPTION OF DRAWINGS

[0034] Figure 1 is a schematic diagram of the method for determining the radar stealth performance of the radar stealth material of an aero-engine after damage provided by the present application. DETAILED DESCRIPTION

[0035] In order to make the technical solutions of the present application and the advantages thereof clearer, the technical solutions of the present application will be further described in detail below with reference to the drawings. It should be understood that the specific embodiments described herein are only some of the embodiments of the present application, and are only used to explain the present application, but not to limit the present application. It should be noted that, for the purpose of description, only parts related to the present application are shown in the drawings, and other related parts can be referred to the general design. In the case of no conflict, the embodiments in the present application and the technical features in the embodiments can be combined to obtain new embodiments.

[0036] In addition, unless otherwise defined, the technical terms or scientific terms used in the present application description should be the general meaning understood by the general technical personnel in the field of the present application. The "first", "second", "third" and similar terms used in the present application description are only for the purpose of description, to distinguish different components, and cannot be understood as indicating or implying relative importance. The "one", "an" or "the" and similar terms used in the present application description should not be understood as an absolute limitation on the number, but should be understood as the presence of at least one. The "including" or "containing" and similar terms used in the present application description mean that the elements or objects appearing before the word cover the elements or objects listed after the word and their equivalents, without excluding other elements or objects.

[0037] The technical solutions of the present application will be further described in detail below with reference to the drawings. Figure 1 The present application will be further described in detail.

[0038] A method for determining the radar stealth performance of an aero-engine radar stealth material after damage, comprising:

[0039] Step one, set n different damage areas of the radar stealth material on each component:

[0040]

[0041] Wherein,

[0042] The nth damage area of the radar stealth material on the ith component;

[0043] γ is the damage conversion coefficient of the radar stealth material on the component, which is close to n in value, and γ = 1.05n can be taken.

[0044] S i The area of the radar stealth material on the ith backward visible component.

[0045] The various components include low-vortex secondary blades, afterburner components, and nozzle expansion sections.

[0046] Step two, using simulation calculation, get the radar stealth performance of aero-engine under different damage area combinations of radar stealth materials on each component. The different damage area combinations mentioned here can be only a series of damage areas of radar stealth materials on a single component, or an orthogonal combination or all combinations between different damage areas of radar stealth materials on some or all components.

[0047] Step three, construct the regression equation of the correlation between the radar stealth performance of aero-engine and the damage area of radar stealth materials on each component:

[0048]

[0049] Wherein,

[0050] I is the radar stealth performance of aero-engine;

[0051] Ai is the damage area of radar stealth materials on the i-th component;

[0052] β0, β1, β2……βi are regression coefficients. i

[0053] Step four, use the radar stealth performance of aero-engine under different damage area combinations of radar stealth materials on each component to train the regression equation, and obtain the regression coefficients β0, β1, β2……βi. i

[0054] A program or existing software can be used to train the regression equation using the radar stealth performance of aero-engine under different damage area combinations of radar stealth materials on each component, and obtain the regression coefficients, so as to determine the relationship between the radar stealth performance of aero-engine and the damage area of radar stealth materials on each component. In order to better determine the regression coefficients, the least square method is introduced to estimate the regression coefficients, and the following relationship is established to obtain the optimal solution of a group of regression coefficients:

[0055]

[0056] Wherein,

[0057] I 真 is the radar stealth performance of aero-engine under different damage area combinations of radar stealth materials on each component obtained by simulation calculation.

[0058] Step five, select an aero-engine, measure the damage area of each component of the aero-engine, use simulation calculation to obtain the radar stealth performance I of the aero-engine, and use the regression equation to calculate the radar stealth performance I of the aero-engine. 仿 预 ​​​​

[0059] If |I 仿 -I 预 If |I 仿 X100%≤5%, indicating that the obtained regression equation of the correlation between the radar stealth performance of the aero-engine and the damaged area of the radar stealth material on each component has high accuracy, and can be used for rapid calculation of the radar stealth performance of the target aero-engine;

[0060] If |I 仿 -I 预 If |I 仿 X100%>5%, indicating that the obtained regression equation of the correlation between the radar stealth performance of the aero-engine and the damaged area of the radar stealth material on each component has low accuracy, at this time, the sample quantity can be expanded by increasing the value of n, and the regression coefficients β0, β1, β2, …, βn are recalculated to obtain a new regression equation. i .

[0061] Step six, measuring the damaged area of each component of the target aero-engine, and calculating the radar stealth performance I of the target aero-engine by using the regression equation. 目 .

[0062] For the method for determining the radar stealth performance of the aero-engine after the damage of the radar stealth material disclosed in the above embodiment, those skilled in the art can understand that, based on the design that there are multiple different damaged areas of the radar stealth material on each component, simulation calculation is adopted to obtain the radar stealth performance of the aero-engine under different combinations of the damaged areas of the radar stealth material on each component, the regression equation of the correlation between the radar stealth performance of the aero-engine and the damaged area of the radar stealth material on each component is trained, the regression coefficients are obtained, an aero-engine is selected, the damaged areas of each component are measured, the radar stealth performance thereof is obtained by simulation calculation, the accuracy of the regression equation is tested, and after the test is passed, the regression equation is used for rapid calculation of the radar stealth performance of the target aero-engine, which can meet the demand for rapid determination of the radar stealth performance of the aero-engine in practice.

[0063] So far, the technical solution of the present application has been described in combination with the preferred embodiments shown in the drawings, and those skilled in the art should understand that the protection scope of the present application is obviously not limited to these specific embodiments, and those skilled in the art can make equivalent changes or replacements to the related technical features without deviating from the principles of the present application, and the technical solutions after the changes or replacements will fall within the protection scope of the present application.

Claims

1. A method for determining the radar stealth performance of an aeroengine radar stealth material after damage, characterized in that, The method comprises the following steps: n different damage areas of radar stealth materials on each component are set; radar stealth performance of the aero-engine under different combinations of damage areas of radar stealth materials on each component is obtained through simulation calculation; a regression equation between the radar stealth performance of the aero-engine and the damage areas of radar stealth materials on each component is constructed; the regression equation is trained by using the radar stealth performance of the aero-engine under different combinations of damage areas of radar stealth materials on each component, and regression coefficients are obtained; the accuracy of the regression equation is verified by selecting an aero-engine, measuring the damage areas of each component of the aero-engine, obtaining the radar stealth performance of the aero-engine through simulation calculation, and calculating the radar stealth performance of the aero-engine by using the regression equation; if the verification fails, the value of n is increased, and the regression coefficients are obtained again; the damage areas of each component of a target aero-engine are measured, and the radar stealth performance of the target aero-engine is calculated by using the regression equation. The n different damage areas of radar stealth materials on each component are specifically as follows: ； wherein, is the nth damage area on the ith component for radar stealth materials; The damage conversion factor of the radar stealth material on the component is close to n in value. A; is the area of the i-th rearward-facing component of radar-stealth material.

2. The method according to claim 1, wherein, 。 3. The method according to claim 1, wherein, the components include low-vortex second-stage blades, components of a booster combustion chamber, and a nozzle expansion section.

4. The method according to claim 1, wherein, the regression equation between the radar stealth performance of the aero-engine and the damage areas of radar stealth materials on each component is specifically as follows: ； wherein, I radar stealth performance of the aero-engine; A is the damage area on the i-th component for radar stealth materials; is the regression coefficient.

5. The method according to claim 1, wherein, When the accuracy of the regression equation is tested, if - | × 100% > 5%, the test fails.

6. The method according to claim 1, wherein, when the regression equation is trained by using the radar stealth performance of the aero-engine under different combinations of damage areas of radar stealth materials on each component, the regression coefficients are estimated by using the least square method.

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