Aerodynamic Design And Study Of A Variable Geometry Two-dimensional Inlet Used In Inner Shunt-wound Turbine Based Combined Cycle

The intake system of TBCC with two-dimensional inlet is simple. The variable geometry is easy to achieve. It can be integrated with the aircraft design. Therefore, the intake system with two-dimensional has good prospects. According to job requirements, two-dimensional TBCC inlet need to work in a wide range of Mach number, and requires a variable geometry. This paper studies the variable geometry scheme with smooth transition connection, and gives a simple, easy and high-performance two-dimensional TBCC variable geometry inlet. The maximum Mach of the inlet is 4.0, and Mach 2.5 is transition mode to achieve model conversion. Changing the inlet geometry, we study the each performance by numerical simulation.1) In order design the two-dimensional inlet for the TBCC inlet in the most Mach number 4.0, this paper studies the two-dimensional lip angle and total angle. When lip angle too small will make the lip shock too strong, it can cause inlet not starting. It else will make too much resistance. External segment total angle increases, the shrinkage ratio of external is greater. In this case the compression is more powerful, but total pressure loss is severer.2) This article is designed TBCC inlet with smooth geometric surface. Smooth transition variable geometry ensures wall continuous smooth when the TBCC is adjusted, and compression performance stronger in smooth structure, more uniform flow field, will help reduce the loss. The variable geometry is simple and reliable, while maintaining a smooth arc transition throughout the process of change. It can avoid unnecessary expansion, with excellent performance to meet variable geometry design requirements.3) Three-dimensional numerical simulation of inlet is studied ramjet mode, turbine mode and transition mode. Wherein the design condition(M?=4.0), the mass-flow coefficient is 0.895, the total pressure recovery coefficient is 0.521, and Mach number in outlet is 0.21. By adjusting the throat height implement variable geometry adjustment. With lower Mach number, the throat height increases, the mass-flow coefficient decreased, total pressure recovery coefficient increases. When Mach number changes, the inlet has a better performance.4) When inlet works in ramjet mode, the channel will be some separation, so that the inlet will be slotted suction in the shock train nearby. The bleeding in behind has greatest impact to inlet. Due to low energy flow exhaust, within the expansion section is not separated from the lower wall, and appear on a certain separation in upper wall. Exports distortion drastically reduced.