A Calculation Method of Motion Derivative of Aircraft

Abstract

The invention relates to the technical field of fluid dynamics, and discloses a method for calculating dynamic derivative of a flight vehicle. The method is characterized in that a static flow field boundary condition b1 I determined according to the flight state of the flight vehicle, and a solution vector, relative to the boundary condition b1, of the fluid field, is solved when a fluid field control equation is convergent to 0, namely, R=Ax+b1=0, wherein A is the matrix of the control equation; if the residual is not convergent to absolute zero, an acceptable converging residual is set as R1=Ax1+b1, and meanwhile, the aerodynamic force is as shown in the formula (seeing the description), and the equation is solved as shown in the description, wherein F is aerodynamic force; R is the residual; x is the solution vector; and thus an adjoint matrix A1 corresponding to the solution vector x1 can be obtained; a rotational angular velocity delta w is added for the flight vehicle around a reference center, and normal movement velocity is generated on the surface of the flight vehicle, and then a residual increment delta R generated by the normal velocity is calculated; the aerodynamic force increment generated by the normal velocity is as shown in the description, and as a result, the dynamic derivative of the aerodynamic force diagonal velocity can be obtained as shown in the description. According to the scheme, the method has the advantage that the solution scheme of the dynamic derivative is simple and accurate.

Description

technical field [0001] The invention relates to the technical field of fluid dynamics, in particular to a method for calculating the dynamic derivative of an aircraft. Background technique [0002] The calculation of aircraft aerodynamic force by CFD method is usually solved as follows: [0003] Ax+b=0 (1) [0004] The large matrix equation of , where matrix A is the matrix representing the governing equation, b represents the boundary condition, and x is the vector to be obtained. [0005] The method to solve the flow field control equation (1) is mainly the time correlation method, and an initial value x is set for the vector x 0 , undergoing a time-varying process [0006] [0007] Finally, the solution of formula (1) is obtained. Among them, R is the residual error, and the process of solving is to make the residual error gradually converge to 0. Existing methods, including tests and calculations, the method for solving the dynamic derivative all is to make the a...

AI Technical Summary

Problems solved by technology

Unsteady process calculation requires high precision, takes a long time, and consumes a lot of resources. If the amplitude of the vibration is too large, the calculation result will contain too many high-order items, and the accuracy will deteriorate; if the amplitude is too small, the variation may If it is too small, the calculation error will bring a large deviation

The wind tunnel test is limited by the test accuracy, and there is also a contradiction in the selection of the amplitude

Images