Numerical Study on Homogeneous Condensation in a Vortex

Abstract

The homogeneous water condensation in a vortex is numerically studied in the present work by using an extended method of moments (EMOM). The EMOM is based on the liquid phase so that the gas phase and the liquid phase can be treated separately, having their own governing equations respectively. The EMOM is integrated into a well validated numerical method-VAS2D (two-dimensional & axisymmetric vectorized adaptive solver), which is a MUSCL-type finite-volume method developed for the unstructured quadrilateral grids. The interactions between the two phases are realized through the source terms including the exchange of momentum and heat. The new numerical method is then applied to a vortex flow with a mixture of nitrogen and water vapor. Several cases with different initial situations are investigated. The evolution of the flow field is discussed. The case with the undersaturated gas apart from the nucleation region has a smooth diffusion of the droplets. But for the case with the supersaturated gas, the droplets continuously grow when they move to the new supersaturated region under the effect of centrifugal force. It leads to a more complex interaction between the vortex and the condensation.