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Aircraft flutter characteristic analysis method with no additional aerodynamic damping

An analysis method and technology of flutter characteristics, applied in instruments, special data processing applications, electrical digital data processing, etc., can solve problems such as unfavorable subcritical damping characteristics and frequency characteristics of aircraft, and achieve the effect of accurate subcritical damping characteristics

Inactive Publication Date: 2013-04-24
NORTHWESTERN POLYTECHNICAL UNIV
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  • Summary
  • Abstract
  • Description
  • Claims
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AI Technical Summary

Problems solved by technology

Compared with the actual model, this method introduces an additional aerodynamic damping term, although the additional aerodynamic damping term tends to disappear at the flutter critical speed, but under subcritical conditions, due to the existence of the additional term, it is not conducive to Obtain accurate subcritical damping characteristics and frequency characteristics of aircraft

Method used

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  • Aircraft flutter characteristic analysis method with no additional aerodynamic damping
  • Aircraft flutter characteristic analysis method with no additional aerodynamic damping
  • Aircraft flutter characteristic analysis method with no additional aerodynamic damping

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Embodiment

[0025] The object model analyzed in this embodiment is as figure 1 As mentioned above, it is a wind tunnel test binary wing model.

[0026] Step 1: According to the original data of the wing model, determine the generalized mass matrix M, generalized damping matrix B, and generalized stiffness matrix K of the model, respectively:

[0027] M = 3.2930 0.0859 0.0859 0.0135 , B = 3.2962 0.03517 0.03517 0.03042 , K = 2818.8 0 ...

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Abstract

The invention provides an aircraft flutter characteristic analysis method with no additional aerodynamic damping, which comprises: building an aircraft aeroelastic model at first, calculating the sub-critical damping and frequency in each mode at each flying speed point within the flying speed scope containing an aircraft flutter critical speed, drawing a change curve of the sub-critical damping and frequency along with the flying speed, and determining the aircraft flutter critical speed. The aircraft flutter analysis equation with no additional aerodynamic damping is introduced, and the damping iteration method is adopted for analysis of sub-critical damping characteristics according to the corresponding nonlinear characteristic value of the equation. Compared with the conventional flutter analysis method with the additional aerodynamic damping, no additional aerodynamic damping needs to be introduced, the obtained sub-critical damping characteristics of aircrafts are more accurate,the determination of the aircraft flutter characteristics can be facilitated, and a reliable basis can be provided for trial flutter flights.

Description

technical field [0001] The invention relates to the technical field of aircraft dynamic strength and stability, in particular to an aircraft flutter characteristic analysis method without additional aerodynamic damping, which is used for analyzing subcritical damping and frequency characteristics of the aircraft. Background technique [0002] During the flight of the aircraft, its wing surface structure will be subject to the coupling effect of unsteady aerodynamic force, inertial force and elastic force, so that at a certain critical flight speed, the structure will experience unattenuated vibration - flutter, causing the aircraft Structural damage leads to the tragedy of aircraft crash, so it is necessary to analyze the flutter characteristics of the aircraft. [0003] The current method of analyzing the flutter characteristics of aircraft is to separate the unsteady aerodynamic force in the flutter analysis equation into aerodynamic stiffness and aerodynamic damping, and ...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): G06F17/50
Inventor 谷迎松杨智春李斌
Owner NORTHWESTERN POLYTECHNICAL UNIV
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