A study on the influence of closure model and numerical technology on the stability of two-fluid model

The influence of closure model and numerical technology on two-fluid model's stability is studied. A stability analysis method for two-fluid model with interfacial drag term is proposed. The stability depends on the eigenvalue spectral radius of a perturbation growth rate matrix. By analyzing eigenvalue spectral radius, the effect of interfacial drag, cell size, time step and time-smoothing is studied. The main findings are: Besides interfacial drag coefficient's magnitude, the mathematic form of drag coefficient model also has large effect. Increase of cell size, decrease of time step and time-smoothing do not necessarily lead to stability enhancement. The effectiveness of stability enhancement technology depends on relationship between spectral radius and cell size, time step and time-smoothing coefficient.