低温环境下高速诱导轮内空化流动特性及机理研究

The investigation on the cavitating flow of cryogenic fluid is of vital importance to the performance and safety of liquid rocket propeller and other launch vehicles. As one of the key components in the liquid rocket engine centrifugal pump, the understandings of the evolution patterns of cavitating flow in the high-speed inducer are the fundamentals to guarantee the normal operation of the centrifugal pump. Since the latent heat of cryogenic fluid is small and the saturation temperature is much lower than the ambient temperature, the vaporization during delivery is inevitable and exhibits vapor-liquid two-phase pattern, whose influences on the cavitating flow in the inducer are not yet clarified.. The present project aims at the practical issue of the operation of centrifugal pump in modern space technologies, and investigates the cavitating flow of cryogenic fluid in the high-speed inducer based on the cavitation theory and characteristics. The cavitation model of cryogenic fluid is modified by the temperature-pressure coupling considering the thermodynamics effect. The experimental platform is established for visualizing the cryogenic two-phase fluid to obtain the flow patterns at the inlet of the high-speed inducer under the state of rotation. The parameters for the bubbles and fluid, which significantly affect the cavitation characteristics of the inducer, are extracted to reveal the influences of bubble formation on the cavitating flow in the inducer, and to identify the internal and external characteristics and the stable operation range of the high-speed inducer.

低温环境下的空化流动研究对液体火箭推进器等发射运载工具的性能及安全性有着重要意义。作为液体火箭发动机离心泵的关键部件之一，掌握高速诱导轮流道内空化流演变规律是保证离心泵正常运行的基础。由于低温液体的汽化潜热小，而且饱和温度远低于周围环境温度，在输送过程中不可避免的气化而呈现气液两相形态，其对诱导轮内空化流态的影响机制不明，亟需开展深入的研究。. 本项目针对现代空间技术中离心泵运行过程的实际问题，基于空化流动理论和低温流体流动特性，开展低温环境下高速诱导轮空化流动特性研究。考虑热力学效应对低温空化流动的影响，对低温空化模型进行温度压力耦合修正；建立低温两相流可视化测试平台，获得旋转状态下高速诱导轮入口流动特性；提取对诱导轮空化特性产生重要影响的气泡参数和液流场参数，揭示输送管路气泡析出对诱导轮内空化湍流流场的影响机理，确定来流气泡作用下高速诱导轮的内外特性及稳定运行范围。

低温环境下的空化流动研究对液体火箭推进器等发射运载工具的性能及安全性有着重要意义。作为液体火箭发动机离心泵的关键部件之一，掌握高速诱导轮流道内空化流演变规律是保证离心泵正常运行的基础。本项目针对现代空间技术中航天涡轮泵诱导轮运行过程的实际问题，基于空化流动理论和低温流体流动特性，开展低温环境下甲烷泵高速诱导轮空化流动特性研究。考虑热力学效应对低温空化流动的影响，对低温空化模型进行温度压力耦合修正；发展了基于边界涡量流和表面摩擦力线的三维流动表征方法，并开展了基于拟涡能的诱导轮能量输运定量评价研究，研究了涡轮泵各主要构件的能量耗散量及其在不同进口压力下的能量输运特性。为揭示和保障高速诱导轮的内外特性及稳定运行范围提供理论支撑。. 通过研究共发表论文13篇，其中SCI检索论文10篇，ESI高被引论文2篇，EI检索1篇，会议论文2篇；以第二完成人获2019年度中国机械工业联合会科技进步奖一等奖1项；合著专著1部；申请专利11项，已授权发明专利2项；培养毕业硕士研究生5名，培养在读博士研究生2名；参加学术会议4次。