Turbulence models for the computation of flow past airplanes

With the availability of large computing power and developments in grid generation and numerical algorithms, it is now possible to compute the flow past an airplane using Reynolds-averaged Navier-Stokes equations. These equations need a model of turbulence to make themselves a closed set. A large number of models of turbulence have been proposed, for example, mixing length models, one-equation models, two-equation models, Reynolds stress models, algebraic stress models, etc. Some reviews on the applications of these models to a variety of flow situations have appeared in the literature over the last 10 years. However, the topic of turbulence models for the computation of flow past airplanes has not received adequate attention. The present review attempts to fill this gap. Keeping this in mind, in Section 1, a brief reference is made to the recent reviews on turbulence modelling. The Reynolds averaged equations for compressible viscous flow are described and the need for turbulence modelling is highlighted in Section 2. In order to gauge the suitability of a turbulence model, the computations based on it should be compared with reliable experimental data. Hence a brief discussion on available benchmark data regarding airplane components is presented in Section 3. Various models of turbulence and modifications to them are described in Section 4. Computations using some of these models and the results thereof are described in Section 5. It appears that the Baldwin and Lomax model is suitable for computation of attached flows and with modification suggested by Degani and Schiff, this model gives good results for flows around bodies with crossflow separation. The Johnson and King model is found to give reasonable results even in the case of separated flows. Two-equation models, algebraic stress models and Reynolds stress models are currently being tried out for the computation of flow past airfoils. Copyright © 1996 Elsevier Science Ltd.