运载火箭动特性中推进剂纵向质量分散建模方法

Propellant longitudinal masses dispersion method in modal analysis of the rocket

将贮箱箱底建模为环段,采用递推公式将推进剂纵向质量分散到环段,代替目前广泛应用的柱段底点纵向耦合质量单元方法,建立了运载火箭动特性模型。分析表明各环段分散量均匀并呈单调递减趋势。计算结果和试验对比表明该建模方法能获取更为精确的模态计算结果。

The tank ellipsoid bottom are modeled as annuluses.Propellant longitudinal masses aredispersed over these annuluses by certain recurrence formulation instead of the wide used coupling masselement method,where propellant longitudinal masses are dispersed just on the lowest point of the tankcylindrical part.The modal analysis model of the rocket is constructed.It is indicated that dispersionmasses over annuluses are uniform and monotone decreasing.The comparison of the computational resultand the experimental data indicates that more accurate modal analysis result can be acquired by thismethod.