Calculation of three-dimensional low Reynolds number flows

Abstract

An interactive boundary-layer stability-transition approach is used to calculate the performance characteristics of an infinite swept wing at low Reynolds numbers for several angles of attack. The in viscid flow solutions are obtained from an inviscid method based on conformal mapping and the viscous flow solutions from an inverse boundary-layer scheme which uses the Hilbert integral formulation to couple the inviscid and viscous flow. The onset of transition is calculated by the e method, based on twoand three-dimensional versions of linear stability theory. Calculated results for an infinite swept wing with an Eppler airfoil cross section are presented for sweep angles corresponding to A = 30, 40, and 45 deg, and for Reynolds numbers of 3 x 10 and 4.6 x 10. The effect of sweep angle on lift and drag coefficients is investigated together with the accuracy of predicting the onset of transition with two versions of the e method.