Modelling of Transonic Flow in Very Narrow Channels

The study is focused on the mathematical modelling of leakage flow in very narrow channels. The problem is solved as a two-dimensional non-stationary turbulent compressible Newtonian fluid flow with ideal gas properties. The turbulent flow is assumed to be statistically steady and the mathematical model is described by the non-linear conservative system of the compressible Favre-averaged Navier-Stokes equations. Its numerical solution is performed using the explicit cell-centred finite volume time stepping scheme of MacCormack algorithm on a structured quadrilateral grid. For the computation of turbulent viscosity, the algebraic Baldwin-Lomax turbulence model is implemented into the presented numerical code. The leakage flow is studied for two given pressure ratios between inlet and outlet of a computational domain.