Yan Zhuan, Liu Xuhui, Yu Yusong, Cao Jie, Liu Xiaodan, Zhang Shurui
Hydrogen Energy and Space Propulsion Laboratory, School of Mechanical, Electronic and Control Engineering, Beijing Jiaotong University, Beijing 100044, China.
Beijing Institute of Control Engineering, Beijing 100190, China.
Micromachines (Basel). 2022 Apr 10;13(4):597. doi: 10.3390/mi13040597.
During the working process of the ADN-based thruster, continuously, heat generated by the chemical reaction in the combustion chamber will transfer along the upstream capillary, the propellant in the capillary continuously absorbs heat under the effect of heat transfer from the wall and undergoes a phase change when the saturation temperature is reached. In this study, effects of the downstream heating temperature (623 K to 923 K) on mass flow rate and pressure change in the capillary were investigated based on the established test platform. Simultaneously, the VOF (volume of fraction) model, and the Lee phase transition model coupled with the Navier-Stokes method was utilized to simulate the spatial distribution of the gas-liquid propellant in the capillary. The results show that the ADN-based propellant firstly formed bubbles on the inner wall surface near the exit of the capillary, and these vapor bubbles moved and grew upstream along the capillary. Due to the cooling effect of the ADN-based propellant inflow, the temperature distribution of the front chamber and capillary gradually reached equilibrium. Bubbles were constantly generated in the capillary, and as the heat reflux intensified, the total volume of bubbles in the capillary continued increasing. Single-phase flow, annular flow, wave flow, and segment plug flow appeared sequentially along the axial direction of the capillary, and the proportion of gas phase volume fraction at the capillary outlet section gradually increased.
在基于ADN的推进器工作过程中，燃烧室内化学反应产生的热量持续沿上游毛细管传递，毛细管内的推进剂在壁面传热作用下不断吸收热量，达到饱和温度时发生相变。本研究基于搭建的试验平台，研究了下游加热温度（623K至923K）对毛细管内质量流量和压力变化的影响。同时，采用VOF（体积分数）模型以及与Navier-Stokes方法耦合的Lee相变模型，对毛细管内气液推进剂的空间分布进行模拟。结果表明，基于ADN的推进剂首先在毛细管出口附近的内壁表面形成气泡，这些蒸汽气泡沿毛细管向上游移动并长大。由于基于ADN的推进剂流入产生的冷却作用，前室和毛细管的温度分布逐渐达到平衡。毛细管内不断产生气泡，随着热回流加剧，毛细管内气泡总体积持续增加。沿毛细管轴向依次出现单相流、环状流、波状流和段塞流，毛细管出口截面处气相体积分数比例逐渐增大。
