采用非定常N-S方程的翼型颤振特性分析研究

Analysis of Airfoil Flutter Characteristics

以非定常 N- S方程为主管方程 ,计算翼型振动的瞬时非定常气动力 ,并与颤振方程耦合求解 ,用时间推进的方法 ,计算了结构响应特性。经多个算例计算 ,研究了颤振的临界速度随马赫数的变化规律以及极限环振荡等非线性特性。计算结果与其它文献计算结果吻合很好。

The flutter characteristics of a airfoil with two degree of freedom was studied, in which the structural parameters were considered as linear. The N-S equations as governing equations were used to calculate the nonlinear unsteady aerodynamics at transonic speed. The flutter motion equations in combination with N-S equations were solved by time advancing method to calculate the structured response. An implicit lower-upper-factorized algorithm in a body-fitted coordinate system was constructed, in which a simple upwind scheme was adopted. Simulation results for NACA64A006 airfoil show that variation of flutter critical velocity with Mach number is given and the nonlinear nature of flutter phenomenon appears clearly.