Whirl flutter analysis method of propeller-driven aircraft

Abstract

The invention relates to a whirl flutter analysis method of a propeller-driven aircraft. The whirl flutter analysis method comprises the following steps: 1) establishing a wing finite element model, and carrying out dynamic characteristic analysis; 2) calculating the dynamic characteristic of a nacelle / propeller system; 3) calculating an unsteady aerodynamic force influence coefficient matrix among wing aerodynamic grids and the aerodynamic influence coefficient matrix, on the sidewash w and the downwash v of a propeller hub point, of the wing aerodynamic grid; 4) calculating the aerodynamic derivatives of the propeller under different flight states, and assembling an aerodynamic matrix; 5) on the basis of an installation relationship of the wing / the nacelle / the propeller, deducing the mathematical expression form of the effective pitch angle and yaw angle of the propeller; 6) obtaining an unsteady aerodynamic force matrix which is applied to a wing installation point by the propeller to obtain a whirl flutter kinematic equation; and 7) solving the whirl flutter kinematic equation, and analyzing whirl flutter characteristics. The whirl flutter analysis method of the propeller-driven aircraft has the advantages of being high in analysis accuracy, wide in application ranges and the like.

Description

technical field [0001] The invention belongs to the field of aeroelastic design, in particular to a method for analyzing spiral flutter of a propeller aircraft. Background technique [0002] The structural relationship of propeller aircraft wing / nacelle / propeller is as follows: figure 1 As shown, foreign countries conduct spiral flutter analysis based on NASTRAN software, which imports propeller aerodynamic force into NASTRAN in the form of aerodynamic stiffness and damping matrix through DMAP language for flutter frequency domain analysis, but users are inconvenient for the load transfer between propellers Write out, while using NASTRAN can not perform time domain simulation. Domestic research on propeller flutter focuses on two-degree-of-freedom propeller stability analysis and four-degree-of-freedom propeller / wing stability analysis considering wing ups and downs and pitching degrees of freedom. There is no effective propeller flutter suitable for engineering model appli...

AI Technical Summary

Problems solved by technology

[0002] The structural relationship of propeller aircraft wing / nacelle / propeller is as follows: figure 1 As shown, foreign countries conduct spiral flutter analysis based on NASTRAN software, which imports propeller aerodynamic force into NASTRAN in the form of aerodynamic stiffness and damping matrix through DMAP language for flutter frequency domain analysis, but users are inconvenient for the load transfer between propellers Write out, while using NASTRAN can not perform time domain simulation

Domestic research on propeller flutter focuses on two-degree-of-freedom propeller stability analysis and four-degree-of-freedom propeller / wing stability analysis considering wing ups and downs and pitching degrees of freedom. There is no effective propeller flutter suitable for engineering model applications. vibration analysis method

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