A Comparison of Theoretical Predictions and Heat-Transfer Measurements for A Flight Experiment at Mach 20, Reentry F

Predicted heating rates were compared with measured laminar, transitional, and turbulent heating rates obtained on a flight vehicle designated Reentry F. The comparisons were made over an altitude range from 36.58 to 18.29 km (120,000 to 60,000 ft) where the flight velocity was approximately 6.10km/sec (20,000 ft/sec, Mach 20). At the higher altitudes the mean trim angle of attach was about 0.1°; however, at the lowest altitude the local effective angle of attack increased to about 1.5° at the most forward measuring station due to vehicle trim and thermal distortion.
The measured transitional and turbulent heating rates agreed well with the predicted rates. Laminar heating rates were in fair agreement with predictions from a linearized laminar flow theory for sharp cones at angle of attack. Predictions of laminar heating rates obtained by using a modified tangent-cone theory were poor when compared with flight and wind-tunnel data at local effective angles of attack greater than a few tenths of a degree.