超音速喷嘴流出系数仿真分析

为获得超高速涡轮泵中超音速喷嘴流出系数随其入口收敛角、喉部直径等几何结构参数的变化规律,采用ANSYS CFD仿真分析工具,以氦气为工质,给定喷嘴入口总压11 MPa、总温300 K、排气背压0.105 MPa,对3种特定喉径的喷嘴分别在7种入口收敛角度下的流场进行仿真分析,获得其压力场、速度场分布及氦气质量流量,并将其与理论质量流量比较,得出喷嘴流出系数。3种特定的喉径分别为2,5,10 mm,7种入口收敛角分别为30°,45°,60°,90°,120°,150°,180°。结果表明:喷嘴流出系数随入口收敛角的增加而降低,随喉径的增大而增加,在2 mm喉径下流出系数最低为83.9%,在10 mm喉径下流出系数最高为99.1%,对后续设计超高速涡轮泵喷嘴结构形式具有指导作用。

Simulation Analysis of Supersonic Nozzle Discharge Coefficient

In order to obtain the variation of discharge coefficient of supersonic nozzle with inlet convergence angle and throat diameter of ultra-high speed turbopump, ANSYS CFD simulation analysis tool is used to determine the total inlet pressure is 11 MPa, the total temperature is 300 K, and the condition of exhaust back pressure of 0.105 MPa, the flow fields of three nozzles with specific throat diameters are simulated under 7 inlet convergence angles, and the distributions of pressure field and velocity field, as well as the mass flow rate of heliumwere obtained. The nozzle discharge coefficient is obtained. The three specific throat diameters are 2, 5, 10 mm, and the seven inletconvergence angles are 30°,45°,60°,90°,120 °,150° and 180°, respectively. The results show that outflow coefficient decreases with the increase of inlet convergence angle and increases with the increase of throat diameter. the lowest outflow coefficient is 83.7% at 2 mm throat diameter and 99.0% at 10 mm throat diameter. The results have an important guiding role for the subsequent design of ultra-high speed turbopump nozzle structure.