SHOCK TUNNEL THEORY AND METHODS FOR DUPLICATING HYPERSONIC FLIGHT CONDITIONS

This paper reviews the scientific research philosophy and discipline layout of Prof. Yung-huai Kuo in the field of thermo-chemically reacting flows occurring in hypersonic flights, and summarizes the research progress in shock tunnel theories and methods for duplicating hypersonic flight conditions. The work has been achieved from 50 years effort dedicated by the High Temperature Gas Dynamics Research Team founded by Prof. Kuo. Rapid generation and rapid application of high temperature gas are an ideal method for wind tunnel operation, and a shock tunnel is such an experimental facility. The fundamental theory and governing equations for shock tunnel are presented first, and these demonstrate the unique advantages of shock tunnel technology for the ground-based testing of hypersonic vehicles. Then the feasibility, basic equations and key problems in the shock tunnel technology for duplicating required hypersonic flight conditions are discussed. Aiming at solving the key problems, a theory is proposed for the detonation-driven shock tunnel from the technical development of detonation driver and its engineering application/verification. Finally, the tailored condition for the detonation-driven shock tunnel is introduced, and lays the foundation for the operation of shock tunnels with long test time. This condition is one of the most difficult problems encountered in developing high-enthalpy shock tunnels. The problem has been investigated for decades, but not solved perfectly. With the proposed theory and methods, several high-enthalpy tunnels are developed for covering the full flight envelope of hypersonic vehicles and its applications show that the theory proposed here is successful and important for aerodynamic and kinetic study in the hypersonic research field.The Team's research work on the hypersonic ground testing facilities has realized the strategic goal of Prof. Kuo's discipline planning, and a world leading research platform was established for exploring hypersonic thermo-chemically reacting flows.