To investigate the relationship between design parameters and ratchet strain of thrust chambers,chambers with different chamber pressures, thrusts and mixture ratios were designed. Quasi 2-D thermal model, nonlinear finite element thermal-structural coupling analysis method and local strain model were utilized to calculate the ratchet strain of different chambers generated during cycle works. Computation results indicated that rather than time of hot run, number of work cycle was the primary factor entailing the deformation of chambers. Thermal condition was the direct rea-son for the influence of design parameters upon ratchet strain. Chambers with higher chamber pres-sure,less thrust and higher mixture ratio generated greater ratchet strain. While ratchet strain of chambers with higher chamber pressure,greater thrust and higher mixture ratio descended along with the work cycle ascending.%为探究可重复使用火箭发动机设计参数对推力室身部在工作过程中热棘轮现象的影响,采用经典的液体火箭发动机设计方法设计了不同室压、推力及混合比的推力室,通过准二维传热计算方法、非线性有限元热-结构耦合分析方法和局部应变法对比了不同设计参数的推力室在工作过程中的棘轮应变及其发展情况.计算结果表明,相同的热试时间,循环工作的发动机推力室比单次工作的发动机推力室产生的应变更大;设计参数对棘轮应变的影响是通过改变推力室热环境来实现的;其他设计参数不变,室压更高、推力更小或混合比更高的推力室的棘轮应变更大;高室压、大推力或高混合比的推力室棘轮应变随循环次数的增加而减小.
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