Tbcc Engine Intake System Design Technology Research

For a hypersonic aircraft, the propulsion system is critical. However, none of the airbreathing engine is capable of complete this task in a large flight envelop independently. Therefore, the development of combined propulsion system becomes more and more important both native and abroad. Based on the performance comparison of different types of engines' specific impulse and voyage, one feasible type is turbo/ram combined cycle engine. America, Japan, and many other countries have made great progress in this field. But our country lagged behind, thus, it is important to carry out investigation on TBCC(Turbine Based Combined Cycle) engine.Air intake system used in TBCC engine is designed and its performance is investigated. The air intake system is divided into two parts: inlet and diffuser. In the inlet design process, equal shock intensity theory is adopted, and three outer compressing shocks are joined at cowl lip, internal compressing shocks lead to the direction of the flow into inlet throat the same as forth coming flow, and a mixed compressing inlet is designed. Boundary layer theory is applied to modify the inlet geometry, and the inlet performance is improved through bleed system. A diffuser design method is presented, and the way of how to choose the center line, section shape and diffuser expand angle are demonstrated. By using CFD technology, the inlet fluid fields at different typical flight condition along the flight trajectory are numerically simulated.From the design and simulating results, we can see that the forebody radius expanded leads to increment of boundary layer thickness, thus increasing the bleed area and resistance. With the coming flow condition changes, the inlet throat Mach number fluctuates in a relatively small range. The diffuser back pressure variable can affect the normal shock intensity and position in the diffuser. With the same throat Mach number, back pressure increase causes the normal shock moves upward and decrease of the total pressure loose, mean while the stability decreases. When...