Flush Air Data System And Analog Computation Of Aerocraft Structure's Thermal Protection

Aerospace plane, combining the functions of plane,transfer device and spacecraft, can fly in the aerosphere with hypersonic speed and move in space orbits, which is one of the key weaponries determining space authority in the twentieth century. Nowadays, it is a hot spot of research for countries.Aerospace plane is required to fly in and out of the aerosphere many times. Each flight lasts for so long as one to two hours, whose speeds range from Mach 12 and Mach 25. As the air at the nose of the plane is compressed by the shock, the retardarce temperature can reach 5000K, much higher than the highest temperature 1400K present metal thermal protection materials can bear. In this case, if traditional air data system is adopted, the pitot tube extruding from the body of plane is aerodynamic heated seriously. And it is difficult to find an appropriate way to cool it. Nevertheless, using a flush air data system on the aerospace plane can overcome this problem well.This thesis calculates the heat environment of the nose on aerospace plane, and proposes an effective thermal protection structure-a single body of plane and thermal protection system. The body is designed to a sandwich type with the propelling agent flowing in the interlayer and carrying off the energy, which derived from the friction of air and the structure surface.In this thesis, many efforts are made on this topic:First, the detecting principles and an optimization design of the flush air data system are discussed;Second, relying on existing thermal protection system and flight parameters, appropriate metal thermal protection system are designed, which is able to reproduced;Third, the heat-flow density of the stagnation point on sharp- nose and the distribution of heat-flow density are ascertained, which base on the highest temperature thermal protection materials can bear flying height of aerospace plane and Mach number. Last, Many parameters are made certain, such as the structure and thickness of the heat shield,structure of cooling bed,pressure of cooling air and velocity of flow, which rely on the distribution of heat-flow density on the nose. Also, the temperature distributions of points inside the skin of the nose are calculated.