用三维欧拉方程计算机身与机翼绕流

COMPUTATIONS OF THE FLOW PAST BODIES AND WINGS USING EULER EQUATIONS

本文用Jameson的三维欧拉方程有限体积法、四步Runge-Kutta时间推进格式,计算机身和大后掠细长机翼的三维可压缩绕流。对钝头机身,用C-O型网格;尖头机身与大后掠细长机翼用H-O型网格。本文介绍钝头旋成体、带座舱前机身和三角翼绕流的计算结果,显示流场等值M线分布,计算压强系数分布与实验比较,以及三角翼大迎角分离涡等。由于用了隐式残值光顺等加速收敛措施,有效地减少推进步数,节省机时。

Based on Jameson's finite volume method for 3-D Euler equations, a computer program, named EU3VOL, has been developed. The computation uses explicit four-stage Runge-Kutta scheme and implicit residual smoothing for acceleration of the convergence. The features of the program developed are that we use C-O and H-O meshes which make the program to be able to apply not only to compute the flow past bodies with blunt or point nose but also to the forebody with canopy and high swept slender wing or wing-body combinations, and that the program can be run on personal computer SUPER PC/AT equipped with DSI-780 co-processor board which has 4 MB of RAM. More than 30,000 grid points can be taken for computations on that personal computer. Some of the computation results obtained by the program are shown in the present paper for flows past blunt bodies of revolution, the forebody with canopy and the delta wing with the free-stream Mach number from subsonic to supersonic. The isomach contours and pressure distributions are shown, and compared with the experiment. The velocity vector distributions plotted in cross-flow planes show the separation vortex for the delta wing at high angle of attack.