Dynamic Stability of Blunt Atmospheric Entry Configurations

A series of free flight-test programs conducted on scale models of various blunt atmospheric entry configurations is discussed. Most of these tests were conducted in the Aeroballistic Research Facility, located at Eglin Air Force Base, Florida. The tests for Reynolds-number effects were conducted in the Hypervelocity Free-Flight Aerodynamic Facility located at NASA Ames Research Center at Moffett Field, California. Because these blunt atmospheric entry shapes have a tendency to experience small angle-of-attack dynamic instabilities leading to limit-cycle motions, the primary purpose of the tests was to determine the dynamic stability characteristics of the configurations. Although all of the aerodynamic parameters were obtained during these tests and are presented in the corresponding references, only the dynamic stability results are discussed. The tests were conducted from subsonic to supersonic Mach numbers, 0.7 to 3.5, Reynolds numbers from 0.27 x 10 6 to 6.97 × 10 6 , and for angles of attack up to 40 deg.