Dynamic stability characterization of re-entry modules at hypersonic Mach numbers

At the time of re-entry modules entering into the atmosphere from space, a small perturbation introduces dynamic oscillations on the vehicle because of their extreme traveling speed. The dynamic stability characteristics of re-entry modules at hypersonic Mach numbers is of considerable relevance to their initial design. In the present paper, the dynamic stability of blunt cone model about 10 is examined with wide range of design parameters such as nose bluntness, semi-vertex angle and center of rotation through theoretical and experimental methods. Theoretical approximations are made over a model based on the standard Newtonian theory. Experiments are conducted at 0.25m hypersonic wind tunnel at M = 8.3 and the following trends are observed from the experimental analysis. Interestingly, the incremental higher nose bluntness, semi-vertex angle and center of rotation reduce the dynamic stability. At higher hypersonic Mach numbers (M > 10), dynamic stability characteristics of the re-entry module are insensitive to the free stream Mach number. However, it is observed that the dynamic stability is increased in proportion to the vibration amplitude at hypersonic speeds. © 2017 World Scientific Publishing Company.