固体火箭发动机塞式喷管两相流场与性能分析

Two-phase Flow Field in Plug Nozzle of Solid Rocket Motor and Its Performance Analysis

为了解固体发动机塞式喷管中两相流场的特点和性能的情况,采用欧拉-拉格朗日两相方法对二维全长塞式喷管的两相流场进行了计算。将纯气相流场和两相流场进行了比较,结果表明由于颗粒相的存在使气流的比热比减小,使得低空环境中,塞锥表面的压强峰后移;高空环境中,塞锥表面的压强会升高。大直径颗粒的运动轨迹受外界反压和塞锥气流变化的影响小,小直径颗粒的运动轨迹受外界反压变化和塞锥气流变化的影响大;在两相流性能方面塞式喷管与钟型喷管类似,微粒直径较大的情况下,塞式喷管的效率较低;塞式喷管的效率随着颗粒含量的升高而降低。

In order to understand the characteristics of two phase flow field and its performance in the two dimensional full length plug nozzle, the Euler-Lagrange approach is adopted to get the numerical simulation resuits. The pure gas flow field and two phase flow field in the plug nozzle are compared. It is shown that at low attitude the pressure peaks along the plug move backward, and at high attitude the design pressure ratio of the plug nozzle shift to a smaller value in two phase flow field. The differences mentioned above are caused by the decrease of the specific heat capacity in the two phase flow as comparing with the pure gas flow. The trajectories of the big particles vary little with the ambient pressure and gas flow on the plug surface while the small particles obeys an inverse law. The plug nozzle has similar characteristics in two phase flow as comparing with the bell nozzle, including that the efficiency of the plug nozzle is lower when there are bigger particles in two phase flow. The efficiency of the plug nozzle decreases as the particle content increases.