运输类飞机/发动机干扰流场纵、横向一体化数值分析

发展了一种计及粘性效应的运输类飞机／发动机气动干扰纵，横向影响的一体化数值分析方法，采用多块网络技术及求解椭圆型偏微分方程方法生成贴体，与边界正交的多块对接网格，对全机／发动机复杂外形的纵，横向绕流流场进行分布区求解，利用Euler方程和可压缩湍流边界层积分方程，研究翼面有粘与无粘强干扰流动，计算结果表明，无论对带翼吊还是尾吊发动机的全机构型，均获得了与实验值吻合良好的结果。

Analysis of Airframe/Propulsion Integration for Complex Transport Aircraft

The installation of the propulsion system on airframe was and is an important problem for civil transport aircraft. It was proven by practice that the interaction between the engine system and the airframe could have a significant impact on the aerodynamic performance of an aircraft. The interference drag and other negative effects related to the engine installation on the high subsonic transport aircraft was a major factor that results in deterioration of aircraft aerodynamic characteristics. Overall optimal design and integration of the propulsion system into the airframe will result in an enhanced performance of the whole aircraft. The high requirements for aerodynamic performance of advanced civil aircraft and the strong interactions existing between the airframe and the propulsion system are such that accurate prediction and careful analysis of the engine installation effects are needed to assess and further improve the whole aircraft performance in the early or even all phases of the design process. This paper focuses on the numerical simulation of flow field over complex transport aircraft. The method is based on a multi block point matched grid generation approach combined with zonal solving strategy for complex flow field. The flow field is divided into a number of non overlapped blocks by a cutout technique. H type grids are generated independently in each block using an elliptic grid generation method, in which the control of the grid quality is accomplished by the forcing function technique of Hilgenstock. The flow field is simulated by solving the Euler equations. On the wing surfaces, the viscous effects are simulated by the employment of the viscous/inviscid interaction (VII) technique. In this study, the boundary layer program uses an integral method to calculate turbulent boundary layers. With the concept of an equivalent inviscid flow, the model of blowing velocity is employed in the VII technique. The effect of the boundary layer on the outer inviscid flow is represented through a transpiration boundary condition derived from the boundary layer parameters. The main benefit of this treatment is that the grid is generated only once in overall computing procedure. Computational results and comparisons with experimental data are presented. The good agreement indicates that the present method is effective in predicting the flows about complex transport aircrafts.