火箭推进

在液氧/煤油火箭发动机地面试验中,为得到液氧贮箱放气系统放气流量与放气阀门动作的响应特性,从而控制箱压的下降速率,验证液氧煤油发动机在低入口压力条件下的工作适应性,对液氧贮箱放气系统的动态特性进行了研究。建立了液氧贮箱二维计算模型,结合试验数据,对低温贮箱内气枕空间的非稳态换热过程进行研究,确定放出气体温度以及相应状态。应用CFD的动网格技术,建立二维计算模型,对放气系统阀门的开关动态特性与过流流量特性进行综合分析,获得了不同通径放气管路的放气流量与箱压的计算关联式,基于理想气体状态方程,完善了箱压计算理论模型。应用该模型量化分析箱压下降速率,为计算箱压控制的准确时间节点提供了操作参考。

The research on the dynamic characteristics of gas-exhaust-system was carried out for the ground test of the LOX/kerosene LRE to obtain the response characteristics of gas-exhaust flow and gas-exhaust valve of LOX tank, and verify the applicability of the LOX/kerosene LRE under a low inlet pressure condition, so as to control the pressure decreasing rate in the LOX tank.A 2-D calculation model for the LOX tank was established.In combination with test data, the unsteady heat transfering process of the ullage in the low-temperature tank was studied to define the temperature and state of the exhausted gas.The moving-grid approach of CFD was adopted to establish the 2D model, so that the dynamic and flow characteristics of the values were analyzed.Based on the ideal gas state equation, the calculating formulas of the gas flow and tank pressure were obtained while the tank pressure calculation model was refined.This model can be used to calculate the pressure decreasing rate in the tank, which can also provide a reference for calculation of the exact beginning time of the tank pressure control.

引言
1 系统原理及计算方法
2 计算及仿真结果分析
3 箱压计算理论模型
4 结论

图1 系统原理图<br/>Fig.1 Principle diagram of the gas-exhaust-system

图1 系统原理图
Fig.1 Principle diagram of the gas-exhaust-system

图2 贮箱内换热特性计算模型<br/>Fig.2 Computational model of heat transfer characteristic in the tank

图2 贮箱内换热特性计算模型
Fig.2 Computational model of heat transfer characteristic in the tank

图3 阀门动态特性仿真模型<br/>Fig.3 Simulation model of valve dynamic characteristic

图3 阀门动态特性仿真模型
Fig.3 Simulation model of valve dynamic characteristic

图4 动网格示意图<br/>Fig.4 Diagram of moving grids

图4 动网格示意图
Fig.4 Diagram of moving grids

图5 300 s时容器内温度分布云图<br/>Fig.5 Contour of temperature distribution at 300 s

图5 300 s时容器内温度分布云图
Fig.5 Contour of temperature distribution at 300 s

表1 气枕平均温度对比<br/>Tab.1 Contrast of ullage gas average temperature in tank

表1 气枕平均温度对比
Tab.1 Contrast of ullage gas average temperature in tank

图6 DN40-0.53 MPa开阀过程压力云图<br/>Fig.6 Pressure cloud chart of DN40 valve open process at 0.53 MPa

图6 DN40-0.53 MPa开阀过程压力云图
Fig.6 Pressure cloud chart of DN40 valve open process at 0.53 MPa

图7 DN80管道质量流量随箱压的变化关系<br/>Fig.7 Variation of mass flow in pipeline of DN80 valve with tank pressure

图7 DN80管道质量流量随箱压的变化关系
Fig.7 Variation of mass flow in pipeline of DN80 valve with tank pressure

图8 DN40管道质量流量随箱压的变化关系<br/>Fig.8 Variation of mass flow in pipeline of DN40 valve with tank pressure

图8 DN40管道质量流量随箱压的变化关系
Fig.8 Variation of mass flow in pipeline of DN40 valve with tank pressure

图9 放气过程箱压计算模型<br/>Fig.9 Computational models of tank pressure in gas-exhaust process

图9 放气过程箱压计算模型
Fig.9 Computational models of tank pressure in gas-exhaust process

图10 计算与实际放气过程箱压下降曲线<br/>Fig.10 Actual and computation curves of tank pressure drop in gas-exhaust process

图10 计算与实际放气过程箱压下降曲线
Fig.10 Actual and computation curves of tank pressure drop in gas-exhaust process

[1] 程向华,厉彦忠,陈二锋,等.新型运载火箭射前预冷液氧贮箱热分层的数值研究[J].西安交通大学学报,2008,42(9):1133-1136.
[2] 程向华,厉彦忠,陈二峰.火箭液氧贮箱热分层现象数值模拟[J].低温工程,2008(2):10-13.
[3] 王磊,厉彦忠,李翠,等.液体火箭贮箱增压排液过程三种气枕模型的数值对比[J].航空动力学报,2011,26(9):1996-2001.
[4] 王赞社,顾兆林,冯诗愚,等.低温推进剂贮箱增压过程的传热传质数学模拟[J].低温工程,2007(6):29-37.
[5] 陈阳,高芳,张振鹏.低温推进剂贮箱增压系统分布参数数值仿真与贮箱的有限体积模型[J].航空动力学报,2008,23(2):323-328.
[6] 尚存存,耑锐,王文.液氧贮箱增压过程中气枕空间温度场的数值模拟[J].低温工程,2011(6):47-65.
[7] 王磊,厉彦忠,李翠,等.液体火箭贮箱增压排液过程温度场数值研究[J].航空动力学报,2011,26(8):1893-1899.
[8] 范瑞祥,田玉蓉,黄兵.新一代运载火箭增压技术研究[J].火箭推进,2012,38(4):10-46.
[9] 穆朋刚, 童飞, 蒲光荣,等.温度对贮箱增压系统的影响分析 [J].火箭推进,2015,41(4):74-78.
[10] 王赞社, 顾兆林, 赵红轩, 王广飙.低温贮箱多路管道增压的一种模糊算法研究[J].火箭推进,2008,34(2):7-12.
[11] 周振君,雷刚,王天祥,等.低温液氮贮箱静置增压及放气特性分析[J].低温技术,2015,43(12):9-12.

备注

引言

1 系统原理及计算方法

2 计算及仿真结果分析

3 箱压计算理论模型

4 结论

期刊信息