CALL FOR CONTRIBUTIONS: Towards numerical benchmark solutions for 3D mixed convection flows in rectangular channels heated from below

Abstract

The main purpose of this paper is to propose two three-dimensional Poiseuille–Rayleigh–Bénard flows (mixed convection flows in horizontal rectangular channels heated from below), covering two different flow ranges, as benchmark problems and to solicit numerical comparisons between various contributors in order to obtain two benchmark solutions for the validation of numerical codes. The second objective is to identify the less perturbing outflow boundary conditions for this flow type. The first test case is a steady longitudinal roll flow in a large aspect ratio channel ( A = L / H = 50 , B = l / H = 10 ) at moderate Reynolds number Re = 50 , Rayleigh number Ra = 5000 and Prandtl number Pr = 0.7 . The second one is a fully-established space and time periodic transversal roll flow in a small aspect ratio channel ( A = 25 , B = 4 ) at small Reynolds number Re = 0.1 , Ra = 2500 and Pr = 7 . The model equations are the incompressible Navier–Stokes equations under the Boussinesq approximation.