火箭推进

以大型运载火箭POGO稳定性为研究背景,针对国内尚无型号应用的注气式蓄压器开展仿真研究。在建立注气式蓄压器动力学模型的基础上,利用航天飞机主发动机的相关参数验证了仿真计算的准确性。仿真计算了蓄压器对推进系统固有频率的影响和四种不同蓄压器的推进系统频率特性。研究了注气流量、注气温度、排气流量和排气时间对蓄压器工作特性的影响。仿真结果表明,随着蓄压器入口压力的增大,溢流孔靠近底部的蓄压器气枕压缩量减小; 注气式蓄压器比贮气式蓄压器能够更有效地避免推进系统频率与箭体结构频率相交。

With the POGO stability of a large launch vehicle as research background, the simulation analysis of a gas-filled accumulator was carried out without any application in China. On the basis of building the dynamic model of a gas-filled accumulator, the accuracy of simulation was validated by using the relevant parameters of the space shuttle main engine. The influences of the accumulator on the natural frequency of a propulsion system and the frequency characteristics of propulsion systems of four different pressure accumulators were calculated. The effects of injection flow rate, injection temperature, venting flow rate and venting time on the dynamic characteristics of accumulator were investigated. The simulation results indicate that the compression capacity of the accumulator's pneumatic die cushion at the bottom of overflow holes decreases with the increase of the inlet pressure. Besides, the gas-filled accumulator can more effectively avoid the intersection of propulsion system frequency and vehicle structural frequency in comparison with traditional accumulator. The research results have a certain reference significance for the development of gas-filled accumulator.

引言
1 注气式蓄压器建模
2 蓄压器对推进系统的影响
3 蓄压器工作特性分析
4 结论

图1 两种注气式蓄压器结构<br/>Fig.1 Structural configurations of two gas-filled accumulators

图1 两种注气式蓄压器结构
Fig.1 Structural configurations of two gas-filled accumulators

图2 推进系统固有频率和阻尼比<br/>Fig.2 Natural frequencies and damping ratios of propulsion system

图2 推进系统固有频率和阻尼比
Fig.2 Natural frequencies and damping ratios of propulsion system

图3 推进系统无量纲固有频率<br/>Fig.3 Dimensionless natural frequencies of propulsion system

图3 推进系统无量纲固有频率
Fig.3 Dimensionless natural frequencies of propulsion system

图4 泵入口压力曲线<br/>Fig.4 Pressure curve at pump inlet

图4 泵入口压力曲线
Fig.4 Pressure curve at pump inlet

图5 不同蓄压器的推进系统频率曲线<br/>Fig.5 Frequency curves for propulsion systems of different accumulators

图5 不同蓄压器的推进系统频率曲线
Fig.5 Frequency curves for propulsion systems of different accumulators

图6 蓄压器-溢流管结构<br/>Fig.6 Structure of accumulator-overflow pipe

图6 蓄压器-溢流管结构
Fig.6 Structure of accumulator-overflow pipe

图7 不同相对特征体积的气枕体积变化曲线<br/>Fig.7 Variation of pneumatic die cushion volume with different relative characteristic volumes

图7 不同相对特征体积的气枕体积变化曲线
Fig.7 Variation of pneumatic die cushion volume with different relative characteristic volumes

图8 不同注气流量的气枕体积变化曲线<br/>Fig.8 Variation of pneumatic die cushion volume with different injection flows

图8 不同注气流量的气枕体积变化曲线
Fig.8 Variation of pneumatic die cushion volume with different injection flows

图9 不同排气流量的气枕体积变化曲线<br/>Fig.9 Variation of pneumatic die cushion volume with different venting flows

图9 不同排气流量的气枕体积变化曲线
Fig.9 Variation of pneumatic die cushion volume with different venting flows

图10 气枕体积维持时间<br/>Fig.10 Gas volume sustain time

图10 气枕体积维持时间
Fig.10 Gas volume sustain time

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备注

引言

1 注气式蓄压器建模

2 蓄压器对推进系统的影响

3 蓄压器工作特性分析

4 结论

期刊信息