真实爆震载荷作用下爆震室动态响应分析与壁厚优化

针对一内径为60mm的爆震室,建立其有限元模型并通过加载实验获取真实爆震载荷,计算分析了多循环工作条件下不同因素对爆震室等效应力的影响,并以此为基础对等壁厚爆震室进行了壁厚优化.研究发现:爆震室后段的等效应力峰值较前段平均高出20MPa;温度因素对爆震室等效应变影响显著,30Hz时最大等效应变较不考虑温度场情况增加51.2%;与材料、温度因素相比,爆震室壁厚对等效应力影响较大,室温条件下,壁厚为0.95mm时,最大等效应力达200MPa,已经基本达到材料的屈服应力极限(205MPa);通过更换模型材料进行计算对比发现,选择具有较高屈服应力极限、弹性模量和较低密度的材料会降低爆震室工作时的等效应力. 

Dynamic response analysis and wall thickness optimization of detonation combustor under actual detonation loading

According to a detonation combustor with 60mm inner diameter,the finite element model was built,and the actual detonation loading obtained by experiments was loaded.The influences of different factors on equivalent stress of detonation combustor were calculated under multi-cycle working condition,and the optimization of the detonation combustor wall with constant thickness was completed.It is found that the peak equivalent stress at rear section is 20MPa higher than that at head section on average.The temperature has a significant effect on the equivalent strain of detonation combustor,and the maximum equivalent strain at 30Hz is increased by 51.2% if the temperature is considered.Compared with the material and temperature,the wall thickness of detonation combustor has great influence on the equivalent stress.Under the room temperature and wall thickness of 0.95mm,the maximum equivalent strain reaches 200MPa,almost reaching the yield limit (205MPa) of the material.The calculation results by replacing the model material show that materials with the characteristics of higher yield limit,modulus of elasticity and lower density can reduce the equivalent stress of detonation combustor.