Influence of Operation Conditions on Condensation and Aerodynamic Shockwave in Supersonic Nozzle

Supersonic nozzle is a critical component of supersonic separator which is recently applied for dehydration in natural gas. In order to investigate the influence of operation conditions on condensation and aerodynamic shockwave in a supersonic nozzle, and optimize the location of drainage in supersonic separator, an experimental apparatus with controllable pressure, temperature, relative humidity and droplet nucleuses was established in this paper. A rectangular supersonic nozzle with optical windows was designed for measuring pressure and droplet parameters under different operation conditions. Then, the location and strength of condensation and aerodynamic shockwave were observed by using pressure sensor, CCD camera based on trajectory image and spectral light extinction instrument. The experimental results showed that, with the increase of gas pressure and relative humidity, the location of condensation moves forward to throat and the intensity also increases, while the location of aerodynamic shockwave moves downstream. The corresponding condensation droplet number density increases up to 1350 per cubic millimeter with the increase of relative humidity of water vapor. Moreover, it is also observed that, impurity particles can promote the condensation and aerodynamic shockwave moves to throat. The condensation even occurs upstream of the throat when there are sufficient foreign particles in the gas.