Numerical simulation of natural gas flows in diffusers for supersonic separators

Diffusers play a vital role in the supersonic separator to convert kinetic energy into pressure energy. The natural gas flows in diffusers were numerically calculated using the navier-stokes equations with the RSM (reynolds stress model). The behavior of gas dynamic parameters was analyzed under conditions of shock waves and boundary layers. The results show that the conical diffuser with high pressure recovery performance is a good choice for the supersonic separator. The shock waves appear as bifurcation structures as a result of the interaction between the shocks and the boundary layer in the conical diffuser. When the swirling flow goes into the diffuser, the strength of the swirl changes the shock positions and the static pressure. The strong swirl results in the shift forward of the shock and the non-uniform distributions of the static pressure.