Analysis of Instability Force Mechanism of Ultra High Speed and Ultra High Pressure Non-contacting Seal under Two Phase Flow

火箭发动机的液体燃油泵、超导发电机等都需要超高速超高压涡轮机械的发展。但是，为了防止泄漏损失，减小了密封间隙，使得非接触式密封的失稳力产生非同步振动。本文对涡轮泵两相流情况下高性能转子的不稳定力和不稳定性进行了实验和理论分析。从这个角度出发，进行了以下研究；(1)分析了双螺旋密封的静、动特性，并与实验结果进行了比较。(2)分析非接触密封两相流力的静、动态特性及转子在两相流作用下的稳定性。结果得到：(1)在分析非接触式密封时，可以采用等效间隙的概念。(2)理论上可以得到两相流密封的静态和动态特性，从而分析泵转子在两相流中的稳定性。

Development of ultra high speed and ultra high pressure turbo-machinery is needed in liquid fuel pump of rocket engine, ultra conductive generator and so on. However nonsynchronous vibration is occured by the instabillity force of non-contacting seal because seal clearance is reduced in order to prevent the leakage loss. In this paper analysis instability force and instability analysis of high performance rotor are experimentally and theoretically perforemed in the case of two phase flow of turbo-pump. From this point of view the following studies are carried out ;(1) Analysis of static and dynamic characteristics of double spiral seal and comparison of the characteristics with experimental results.(2) Analysis of static and dynamic characteristics of two phase flow force through non-contacting seal and stability of rotor under the two phase flow.As the result, the followings are obtained ;(1) Idea of equivalent clearance can be avairable in the analysis of non-contacting seal.(2) Static and dynamic characteristics of two phase flow seal can be theoretically obtained, then stability of pump rotor in the two phase flow can be analyzed.