双螺杆固液混合燃料输送系统设计与实验研究

固液燃料混合推进是航天推进系统的重要环节，液体发动机燃料热熵低，为了提高火箭或导弹的续航能力，结合固体粉末燃料热熵高的特点，采取了固液混合燃烧的策略，进而提高发动机燃料的热熵，增加发动机的续航里程。本文根据齿轮啮合原理，对关键结构双螺杆齿形展开修形设计，建立了流道三维模型和仿真模型；在齿形设计的基础上，围绕固液混合均匀、变比例输送开展固液混输系统集成设计，完成整机的加工、装配、调试，搭建实验平台，建立液压测试系统，开展实验。结果表明，设计的两相流泵实现了固液两相物料的混合输送，实现了固液燃料变流量、变比例、变出口压力的均匀混合效果。该小型燃料泵能够实现出口流量30 ~ 600L/h、出口压力0 ~ 900kPa、固液混合比例0% ~ 10%的固液混输，且混输效果良好，研究结构可供设计变推力火箭发动机参考。

Design and Experimental Study of Solid Liquid Mixed Fuel Supply System with Twin Screw

Solid-liquid hybrid propulsion plays an important role in space propulsion system. The thermal entropy of liquid engine fuel is lower than solid powder fuel. In order to improve the endurance of rocket or missile, the strategy of solid-liquid hybrid combustion was adopted, which could improve the thermal entropy of engine fuel and increase the endurance of engine. In this paper, a solid-liquid fuel pump was designed based on numerical simulation and experimental research. According to the principle of gear engagement, the tooth shape of the key structure twin-screw was modified, and the three-dimensional model and simulation model of the flow channel were established. Based on the design of tooth shape, the integrated design of the solid-liquid mixed transportation system was carried out around the uniform and variable proportion transportation of solid-liquid. Further, the processing, assembly and debugging of the whole machine were completed, the experimental platform was built, and the hydraulic testing system was established for experiment. The results showed that the design of the two-phase flow pump realized the mixed transportation of solid-liquid two-phase materials, as well as met the well-mixed requirements of variable flow rate, variable proportion and variable outlet pressure. This small fuel pump can achieve solid-liquid well-mixed with outlet flow within 30~600 L/h, outlet pressure within 0~900 kPa and solid-liquid mixing ratio within 0% ~ 10%, which could provide reference for designing variable thrust rocket engine.