Exact analytical solutions for fully-developed, steady-state laminar mixed convection with heat and mass transfer between vertical parallel plates are presented. The thermal boundary conditions are UWT or UHF while the concentration at each wall is assumed to be uniform but not necessarily the same. The solution for the UWT case depends on a single parameter which combines the effects of thermal and solutal buoyancy. In the UHF case it depends on three independent parameters, the ratio of the thermal Grashof number to the Reynolds number, the ratio of the solutal Grashof number to the Reynolds number, and the wall heat flux ratio.

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SUMMARY A numerical investigation on low‐Reynolds‐number external aerodynamics was conducted using the transitional unsteady Reynolds‐averaged Navier–Stokes shear stress transport γ −Reθ model and the ANSYS‐CFX computational fluid dynamics suite. The NACA 0012 airfoil was exposed to chord‐based Reynolds numbers of 5.0 ×104, 1.0 ×105 and 2.5 ×105 at 0°, 4°and 8°angles of attack. Time‐averaged and instantaneous flow features were extracted and compared with fully turbulent shear stress transport results, XFLR5 panel e N method results, and published higher order numerical and experimental studies. The current model was shown to reproduce the complex flow phenomena, including the laminar separation bubble dynamics and aerodynamic performance, with a very good degree of accuracy. The sensitivity of the model to domain size, grid resolution and quality, timestepping scheme, and free‐stream turbulence intensity was also presented. In view of the results obtained, the proposed model is deemed appropriate for modelling low‐Reynolds‐number external aerodynamics and provides a framework for future studies for the better understanding of this complex flow regime. Copyright © 2011 John Wiley & Sons, Ltd.

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