AN INTERACTIVE BOUNDARY-LAYER METHOD FOR MULTIELEMENT AIRFOILS

A calculation method for the aerodynamic prediction of multielement ai rfoils based on an interactive boundary-layer approach using an improv ed Cebeci-Smith eddy viscosity formulation is described. Results are f irst presented for single airfoils at low and moderate Reynolds number s in order to demonstrate the need to calculate transition for accurat e drag polar prediction and the ability of the improved Cebeci-Smith t urbulence model to predict flews with extensive separation, and theref ore to predict maximum lift coefficient. Results, in terms of pressure distributions and lift, drag and moment coefficients, are presented f or a series of multielement airfoils with flaps and slats. The importa nce of the compressibility effects and the turbulence model on stall, and, again, the need to calculate the onset of transition, are demonst rated. Finally, recommendations are made for the preferred approach to predicting the aerodynamic performance of multielement airfoils for u se as a practical and efficient design tool. (C) 1998 Elsevier Science Ltd. All rights reserved.