助推器头部跨音速脉动压力CFD数值仿真

CFD Numerical Simulation of Fluctuating Pressure Between Booster’s Nosecone and Core Stage in Transonic Flow Field

为计算大型捆绑火箭助推器头部的脉动压力,对直头锥、斜头锥2种典型助推器头部外形流场开展了流场仿真,获得了流场规律及脉动压力,重点模拟了激波/边界层干扰导致的分离流动及激波在附近物面的往复振荡现象,获得了脉动压力结果。研究表明:对于直头锥、斜头锥2种不同外形的助推器,最大均方根脉动压力系数出现的马赫数和量级均不同,与芯级干扰的程度也不同,但二者的能量都集中于低频,且随着马赫数的增大,跨音速效应均明显减少。

To calculate the fluctuating pressure on the head of the booster in the large strap-on rocket, the head shape flow fields of the straight head cone and the oblique head cone were simulated. The flow field law, the fluctuating pressure characteristics and the laws of rocket booster head were obtained. The time-marching method for unsteady flow and the RANS/LES method for turbulence were adopted in studying the fluctuating pressures between the booster and the rocket, especially those caused by the shockwave/bound-layer interaction. The fluctuating pressure characteristics with different shapes of booster nose cones or different March numbers were obtained. The simulation results showed that the positive cone and oblique cone had different numbers and orders of Mach for the occurrence of maximum Prms coefficient. Furthermore, boosters with different shapes would cause interference with the core stage in different degrees. But, the power of both shapes concentrated in low frequencies and the transonic flow effect decreased with the increase of the Mach number.