HEAT-TRANSFER MEASUREMENTS ON THE APEXES OF TWO 60° SWEPTBACK DELTA WINGS (PANEL SEMIAPEX ANGLE OF 30°) HAVING 0° AND 45° DIHEDRAL AT A MACH NUMBER OF 4.95

摘要

An experimental investigation was conducted to evaluate the heat-transfer rates at the apex of two 60° sweptback delta wings (panel semi-apex angle of 30°) having cylindrical leading edges and 0° and 45° positive dihedral. The models tested might correspond to the first several feet of a hypersonic reentry vehicle. The tests were conducted at a Mach number of 4.95 and a stagnation temperature of 400° F. The nominal test-section unit Reynolds numbers varied from 2 X 106 to 12 x 106 per foot.nThe results of the investigation indicated that the laminar heat-transfer distributions (ratio of local to stagnation-line heating rate) about the models normal to the leading edges were in close agreement with two-dimensional blunt-body theory. The three-dimensional stagnation-point heat-transfer rate on the 0° dihedral model was in excellent agree¬ment with theory and the stagnation-line heat transfer on the straight portion of the leading edge of both models approached a constant level 12 percent above the theoretical stagnation-line level on an isolated swept infinite cylinder.nWhen the heating rates on the 4-5° dihedral model (planform sweep of 69'3°) were compared with those on the 0° dihedral model (planform sweep of 6o°) at equal angles of attack and equal lifts greater than zero, the stagnation-line heating rates on the 4-5° dihedral model were, in general, considerably lower as a result of the difference in effec¬tive sweeps of the leading edges. On the wing panels inboard from the stagnation lines, the differences in heating were very small.