Unsteady vorticity–streamfunction algorithm for external flows

• Published in: Computers & fluids Vol. 30; no. 1; pp. 69 - 87
• Main Authors: Sørensen, Jens N., Nygreen, Per J.
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.09.2000
• Subjects: Algorithms; Finite difference method; Finite volume method; Navier Stokes equations; Turbulent flow; Unsteady flow; Viscosity; Vortex flow; vorticity–streamfunction; Navier–Stokes equations; vorticity–streamfunction; Unsteady flow
• ISSN: 0045-7930; 1879-0747
• DOI: 10.1016/S0045-7930(00)00004-9

A non-inertial vorticity–streamfunction algorithm of the Reynolds-averaged Navier–Stokes equations is developed for studying unsteady and turbulent flows past airfoils. The equations are solved on a non-orthogonal C-grid using a combined finite-difference/finite-volume technique. Comparative computations are carried out employing three different turbulence models. These are the algebraic zero-equation model of Baldwin and Lomax [1], and the one-equation models of Baldwin and Barth [2] and Spalart and Allmaras [3]. The performance of the models is evaluated against experiments of the Aérospatiale-A airfoil at incidences up to 40° and against two cases of an oscillating NACA 0015 airfoil experiencing light and deep stall. The computations demonstrate that the vorticity–streamfunction formulation combined with standard eddy-viscosity turbulence models is capable of predicting accurately unsteady and turbulent flows past airfoils.