Flow at low Mach number and zero incidence about M6 wing

Results from FP were obtained corresponding to M_∞ = 0.2 and a = 0 and, as noted, with the input files generated by FPCON with the c_l and/or c_d convergence' option selected.There are no exceptional features in the grid likely to lead to inaccuracy in flow results. Values obtained from FP for the coefficients of (overall) lift and drag are very small, respectively C_L = -0.00009, and C_D = -0.00087, which may be regarded as very satisfactory, since the theoretical values are zero. The sectional coefficient values. It is seen that values are very small, as they should be. Values of are positive inboard and negative outboard, which is a known characteristic of inviscid flow over a swept wing. In integrating over the span to obtain the overall drag, the positive and negative contributions should cancel. It is remarkable that the result from FP in this case for the overall drag coefficient is as small as it is, bearing in mind that it is obtained by integration of surface pressures, and that the sectional drag coefficient values (which are also obtained by integration of pressures) have magnitudes up to nearly 0.03.