颤振边界高效精确预测分析

高效精确地确定多种飞机构型的颤振边界在飞机设计过程中具有重要意义。为了提高计算效率和计算结果的准确性，针对亚声速和跨声速两种马赫数区域，提出分别采用线性和非线性方法进行非定常气动力分析。非线性分析在引入精确的定常气动力的基础上，采用高效率跨声速小扰动方程进行求解；颤振求解统一采用g 法。对大型飞机的梁架—减缩刚度组合模型的空机及三种典型燃油构型进行涵盖飞行包线的全马赫数变高度颤振分析，结果表明：四种构型的颤振边界与颤振试飞边界一致，与其他分析方法相比，效率有明显提高，尤其是对多种飞机构型能够高效地获得准确的颤振边界，即说明本文采用的方法是目前适用于工程上的一种高效精确的预测大型飞机颤振边界的方法。

The High Efficiency and Accuracy Prediction Method Analysis of the Flutter

It is significant to efficiently and accurately determine the flutter boundary of various aircraft configurations in the aircraft design. In this paper, adopt the linear unsteady aerodynamic method and nonlinear unsteady aerodynamic method for the subsonic and transonic areas, respectively. The nonlinear method uses the transonic small disturbance equation based on the accuracy steady CFD results as inputs. All the flutter solutions use g method for different Mach areas. The flutter analysis is used for an beam and reduced stiffness FEM model of the whole aircraft including empty aircraft and three special fuel cases for choosing the typical altitudes and Mach number covering the flight envelope and determine the flutter envelopes for the four aircraft configuration. The flutter boundary of the aircraft is consistent with flight flutter test. Compared with other analysis methods, the efficiency is obviously improved, especially for a variety of aircraft configurations. Therefore, the method adopted in this paper is an efficient and accurate method for predicting flutter boundary of large aircraft, which is suitable for engineering at present.