液体火箭发动机再生冷却结构弹塑性分析

Elastoplastic analysis of regenerative cooling structure of liquid rocket engine

为了分析推力室壁应力和变形分布情况,研究推力室失效位置和失效机理,建立了一种弹塑性有限元分析方法。建立推力室一维流动传热模型,为结构弹塑性分析提供输入。进一步建立推力室壁在温度和压强载荷下的二维弹塑性计算模型,分析了在预冷-工作-后冷-关机的工作循环下推力室壁的应力应变响应,比较了温度载荷和压强载荷的作用程度,并预估了推力室使用寿命。结果表明:推力室壁产生的弹塑性变形是由温度载荷和压强载荷共同作用所致,温度载荷起主导作用。推力室内壁冷却通道中心位置最先发生失效破坏,限制了推力室的使用寿命。从计算时间和准确性来说,该方法能够为再生冷却通道的优化设计和性能估算提供参考。

In order to analyze the stress and deformation distribution on the thrust chamber wall,and study its failure position and mechanism,an elastoplastic finite element analysis method was established.A one-dimensional thermofluid model for the thrust chamber was set up to provide input for the elastoplastic analysis.A two-dimensional elastoplastic calculation model for the thrust chamber wall under thermal and pressure load was established.The stress-strain response of the thrust chamber wall under the working cycle of pre-cooling,hot run,post-cooling and relaxation was analyzed.Then,the effect degree of thermal load and pressure load was compared.The life time of the thrust chamber was estimated.The results showed that,the elastoplastic deformation of thrust chamber wall was caused by the combined action of thermal load and pressure load,and the thermal load played a leading role.Failure of the thrust chamber occurred first in the center of the cooling channel,which limited the service lifetime of thrust chamber.In terms of calculation time and accuracy,the proposed method can provide a reference for optimal design and performance estimation of regenerative cooling channels.