航空学报 > 2022, Vol. 43 Issue (2): 125047-125047   doi: 10.7527/S1000-6893.2021.25047

管路中常温推进剂的两相充填特性仿真

任孝文1, 李平2, 陈宏玉1, 周晨初1   

  1. 1. 西安航天动力研究所 液体火箭发动机技术重点实验室, 西安 710100;
    2. 航天推进技术研究院, 西安 710100
  • 收稿日期:2020-12-03 修回日期:2020-12-28 发布日期:2022-03-04
  • 通讯作者: 任孝文 E-mail:xwrenspx@163.com
  • 基金资助:
    液体火箭发动机技术重点实验室开放基金(6142704180308)

Simulation of two-phase filling characteristics of storable propellant in pipelines

REN Xiaowen1, LI Ping2, CHEN Hongyu1, ZHOU Chenchu1   

  1. 1. Science and Technology on Liquid Rocket Engine Laboratory, Xi'an Aerospace Propulsion Institute, Xi'an 710100, China;
    2. Academy of Aerospace Propulsion Technology, Xi'an 710100, China
  • Received:2020-12-03 Revised:2020-12-28 Published:2022-03-04
  • Supported by:
    Open Fund of the Science and Technology on Liquid Rocket Engine Laboratory (6142704180308)

摘要: 常温推进剂在管路中的两相充填特性由于气液相间的相互作用而难以预测。为拓展液体火箭发动机瞬态特性模块化通用仿真模型库对两相充填的仿真能力,基于Modelica模块化建模思想开发了一维有限体积的两相充填管路模型,其中采用等效流容方程计算压力,使用Volume of Fluid (VOF)法捕捉气液界面。对流项离散格式的比较表明,TVD_QUICK格式可同时满足系统仿真对准确性和实时性的要求。对节流孔径的研究表明,在不同的节流孔径比范围内,液体对预存气体管路的充填过程可分为水击效应忽略、水击效应微弱以及水击效应主导3种模式,且最大水击压力峰值一般发生在水击效应主导模式下。此外,夹带有单个气柱的常温推进剂在充填过程中表现出的压力振荡主要由2个因素造成:气柱受到上下游液柱的压缩而产生的压力波动和下游液柱在节流元件位置产生的水击压力振荡;在2种压力波动的耦合作用下管内瞬时压力峰值达到上游供应压力的5倍左右。

关键词: 常温推进剂, 充填, 管路, 气液两相, 水击

Abstract: The two-phase filling characteristics of the storable propellant in the pipeline are difficult to predict due to the interaction of gas and liquid. To expand the simulation capabilities of the modular general simulation library for liquid rocket engine transient characteristics for two-phase filling, a two-phase filling pipeline model with one-dimensional finite volume is developed based on the Modelica modular modeling idea. In this model, the equivalent fluid capacity equation and the Volume of Fluid (VOF) method are adopted to calculate the pressure and capture the gas-liquid interface, respectively. The comparison of the discrete formats of advection terms shows that the TVD_QUICK scheme can guarantee the accuracy and real-time performance simultaneously for system simulation. The research on the orifice diameter shows that the filling process of the liquid to the pre-existing gas pipeline can be divided into three modes within the range of different throttle aperture ratios, namely, negligible water hammer effect, weak water hammer effect and dominant water hammer effect, and the peak pressure of water hammer generally occurs in the mode of dominant water hammer effect. In addition, the pressure shock shown by the storable propellant with a single gas column in the filling process is mainly caused by two factors. One is the pressure fluctuation of gas column compressed by the upstream and downstream liquid columns, and the other is the water hammer pressure shock generated by the liquid column downstream of the air column at the position of the throttle element. With the coupling of the two pressure fluctuations, the peak water hammer pressure in the pipeline reaches about 5 times the upstream supply pressure.

Key words: storable propellant, filling, pipelines, gas-liquid two-phase, water hammer

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