Supersonic separator is a device for dehydrating and separating heavy hydrocarbons in natural gas. Laval nozzle and cyclone in the separator have a great influence on the separation efficiency. At present, there are few studies on the energy distribution characteristics of the cyclone, and the law of the influence of cyclone on subsonic and transonic flow fields is not clear. Based on numerical simulation, the paper studies the influence of gas-liquid density on the separation performance of the separator, studies the energy distribution characteristics of methane flow in Laval nozzle under subsonic and transonic velocities, and deduces the energy equation containing axial kinetic energy term and radial kinetic energy term in the nozzle. The results show that the gas-liquid density has some effects on the separation efficiency of the separator. The distribution of tangential velocity and tangential kinetic energy in the nozzle is similar before the cyclone along the axis, but after the cyclone, the distribution of tangential velocity and tangential kinetic energy is significantly different. The proposal of tangential kinetic energy has important guiding significance to the structure design of supersonic separator.

超音速分离器是一种用于对天然气中的重质烃进行脱水和分离的装置。分离器中的拉瓦喷嘴和旋风分离器对分离效率有很大影响。目前，关于旋风分离器能量分布特性的研究很少，旋风分离器对亚音速和跨音速流场的影响规律尚不清楚。在数值模拟的基础上，研究了气液密度对分离器分离性能的影响，研究了亚音速和跨音速速度下拉瓦尔喷口内甲烷流的能量分布特征，推导了包含轴向动能项的能量方程。和喷嘴中的径向动能项。结果表明，气液密度对分离器的分离效率有一定影响。喷嘴中切向速度和切向动能的分布在旋风分离器沿轴线之前是相似的，但是在旋风分离器之后，切向速度和切向动能的分布是明显不同的。切向动能的提出对超声速分离器的结构设计具有重要的指导意义。