Aspects of thermal flow control in hypersonic flight

This paper discusses the application of energy deposition for sonic boom mitigation and as actuator device substitute. Classical sonic boom minimization strategies suffer from major shortcomings, such as prohibitively large power requirements or a permanent deterioration of aerodynamic quality - even when sonic boom suppression is not needed. Virtual blunting is suggested here as a combination of classical approaches but with increased flexibility at reduced power consumption. A power estimation based on Rayleigh flow proves to be sufficiently accurate. Numerical simulations are carried out to show that energy deposition is in principle capable of affecting a flow in the same way as a solid spike attachment does. As a second focus, energy deposition is investigated as a mechanism to create forces and torques. As mechanical actuators such as ailerons and rudders are subject to substantial mechanical and thermal loads, it seems desirable to look for alternatives that do not need the weight and complexity of moving parts. It will be shown that forces released on a flow-parallel wall using energy deposition are comparable to forces caused by an inclined flat plate.