Investigation and recent developments in aerodynamic heating and drag reduction for hypersonic flows

Investigation on new methods of drag reduction and thermal protection for hypersonic velocities are proposed based on the new technologies for shock reconstruction. In principle, a blunt vehicle flying at high speeds generates a strong bow shock wave ahead of its nose, which is responsible for the high drag and aero heating levels. There have been a number of efforts devoted towards reducing both the drag and the aero heating by modifying the flow field ahead of the vehicle’s nose. An introduction to the philosophy and recent development in hypersonic aerodynamic heating and drag reduction techniques are presented. These techniques are classified in four major group. Geometrical, mass injection, energy deposition, and magneto aerodynamic techniques. In this review, these new techniques and investigation of the philosophy and development procedure of these techniques are brought to the table and then the effects of each method on drag wave and aerodynamic heating reduction is shown. Geometrical techniques such as structural spike and aerodisk, cavity, multi-row disk (MRD) use to drag reduction. Mass injection techniques like arrays of micro jets, spike and jet, heat addition and plasma injection are very useful to aerodynamic heating reduction. Energy deposition techniques by using laser and plasma can reduce aerodynamic heating and wave drag of hypersonic flows. Magneto aerodynamic technique can reduce drag and aerodynamic heating, by the addition of the magneto technology in hypersonic flows. The present paper is devoted to surveying these studies and illustrating the contributions of the authors in this field. Not only do the paper criticize the previous investigations but also raises some of the areas in the field that need further investigations.