On the Second-order Tunnel-wall-constriction Corrections in Two-dimensional Compressible Flow

Solutions of the first- and second-order Prandtl-Busemann iteration equations are obtained for the flow past thin, sharp-nose, symmetric, two-dimensional bodies in closed channels. With the use of these solutions an expression is derived for the tunnel-wall interference. The tunnel-wall correction for a parabolic-arc airfoil is calculated to indicate the effects of compressibility, ratio of the tunnel height to the airfoil chord, and airfoil thickness coefficient. It appears that, for cases where the tunnel-wall corrections are significant, both the second-order effects and the variation of the correction along the chord should be considered.