Supersonic nozzles are recently applied for carrying out water separation from natural gas streams and dew pointing in early stages of gas processing. This paper represents an experimentally and numerically study on a novel low-pressure two-phase driven supersonic nozzle constructed based on a new annular design. The nozzle includes a set of tilted fixed blades at the entrance and a swirling stabilizer along with a convergence-divergence nozzle. The liquid phase is separated from the primary gas phase by decompression and compression happening accompanied with the centrifugal effect induced by the swirling of the gas stream. The phase change happens by gradual drops in temperature and pressure upstream of the shockwave position, and an abrupt change at the shockwave position followed by a subsequent gradual increase in temperature and pressure. The pressure, temperature, and moisture level of the gas are measured to investigate the performance of the supersonic separation unit.

The computation is carried out by a 2D approach capable of two-phase heat and mass transfer modeling. For the first time, the analysis uses high order of discretization schemes in order to well capture the shockwaves in a low-pressure supersonic nozzle and find out their effects on separation. An assessment is carried out focusing on the effect of operational conditions on the nozzle performance. The experimental data for dehydration efficiencies are in good agreement with the simulation results within 3%.

The shockwave position is found in the range of 0.3–0.5 of non-dimensional nozzle length. The positions of both shockwave and initiation of condensation are shifted toward the exit side when the nozzle pressure ratio decreases. Reducing the pressure ratio from 0.8 to 0.6 will enhance the dehydration efficiency by about 5%.

超音速喷嘴最近被用于在天然气处理的早期阶段中从天然气流和露点中进行水分离。本文对基于新型环形设计的新型低压两相驱动超音速喷嘴进行了实验和数值研究。该喷嘴包括一组在入口处倾斜的固定叶片，一个旋流稳定器以及一个会聚-发散喷嘴。通过减压和压缩，伴随着气流旋流引起的离心作用，使液相与主气相分离。相变通过冲击波位置上游的温度和压力逐渐下降而发生，并且在冲击波位置突然变化，随后温度和压力随后逐渐升高。

通过能够进行两相传热和传质建模的2D方法进行计算。该分析首次使用高阶离散化方案，以很好地捕获低压超音速喷嘴中的冲击波，并找出它们对分离的影响。评估的重点是工作条件对喷嘴性能的影响。脱水效率的实验数据与模拟结果吻合在3％以内。

发现冲击波位置在无量纲喷嘴长度的0.3–0.5范围内。当喷嘴压力比降低时，冲击波和凝结开始的位置都向出口侧移动。将压力比从0.8降低到0.6将使脱水效率提高约5％。