PREDICTION OF TRANSPIRED TURBULENT BOUNDARY-LAYERS WITH ARBITRARY PRESSURE-GRADIENTS

An integral method, using Coles combined inner and outer law as the ve locity profile, is developed for calculation of turbulent boundary lay ers with blowing or suction and pressure gradients. The resulting ordi nary differential equations are solved numerically for the distributio n of skin friction coefficient and integral thickness along the surfac e. Comparisons of predicted skin friction coefficients with experiment al data are made for a wide range of blowing and suction rates and for various pressure gradients, including adverse, zero and a strong favo rable gradient. In addition to good agreement with experimental data f or constant blowing functions F, the method is also successfully teste d on cases where the blowing fraction is variable with position. Predi ctions, in general, exhibit satisfactory agreement with the data. The integral method predictions are comparable to, or better than, a numbe r of finite difference procedures in a limited number of cases where c omparisons were made.