运载火箭主动上升段跨声速抖振问题

Transonic Buffeting in the Active Ascending Phase of a Launch Vehicle

运载火箭在跨声速飞行时,在火箭横截面变化的位置,如锥-柱-肩部和锤头外形收缩段等,会出现附体紊流边层、分离流和激波振荡而产生压力脉动,作用于箭体产生抖振,引起箭体的弯曲振动、板壳的呼吸振荡和结构振动,会对箭体结构和仪器设备造成影响。针对锤头外形火箭潜在的跨声速抖振问题,基于抖振载荷的产生机理给出了具体的风洞试验方案和数据处理方法及抖振载荷计算方法。对某锤头外形火箭进行研究,结果表明,火箭前两阶模态对抖振载荷的贡献最大,且一阶模态和二阶模态引起的载荷分布存在较大差异。因此,在计算火箭的抖振载荷时,至少需考虑两阶模态。

When a carrier rocket flies at transonic speeds,there will be turbulent boundary layers,separation flow,and shock wave oscillation at the positions where the cross section of the rocket changes such as cone-column-shoulder section,and the hammerhead shape contraction section,resulting in pressure pulsations.This will act on the arrow body to produce buffeting,resulting in bending vibration of the arrow body,breathing oscillation of the plate and shell,and structural vibration,which will affect the structure and instruments of the arrow body.A specific wind tunnel test scheme,data processing method,and buffeting load method are proposed based on the generation mechanism of the potential transonic buffeting problem of hammerhead shaped rockets.The results show that the first two modes of rocket make the greatest contribution to the chattering load,and the load distribution caused by the first and the second modes is quite different.Therefore,more than two modes should be considered in the calculation of the chattering load of rocket.