Experimental Technology Study Of The Inlet In Hypersonic Pulse Wind Tunnel

Ramjet engine has been applied to various high-speed vehicle widely because of its light weight, small volume, simple structure, good performance. As a vital part of ramjet, the main objective of the inlet is to introduce the air to achieve the compressing process and it has a dramatic effect on its characteristic. Wind tunnel test is an important way to investigate the design and assessment of the inlet, it aims to obtain reasonable inlet surface, aerodynamic characteristics and matching characteristics to engine of the inlet. The wind tunnel test offers technical support in the inlet project design directly and also offers important references to numerical simulation.With the development of modern hypersonic air breathing vehicle, especially for high speed and long range instancy requirement in military, some new challenging ramjet technologies are produced. The heating environment with low heat flux for a long time makes the total heating very large, the thermal heat has much more effect on missile-borne equipment. Shock tunnel has some particular advantages in heat flux measurement: high speed and high enthalpy or high Reynolds number can be simulated in shock tunnel; the temperature and lateral heat conduction of test model varies small; the sensor can't be destroyed by high heat flux.The experiment technology of inlet test in the pulse wind tunnel FD-20a was studied in the present thesis, it aims to investigate the heat flux, pressure distribution of the inlet model and the method of inlet test, and validate its feasibility. A fixed geometry mixed-pressure axisymmetric inlet model was designed, and the simultaneous project on external flow and internal flow measurement was established. The experiment was completed in the pulse wind tunnel of CAAA. Heat flux, pressure distribution and other parameters of the inlet were given.The internal flow of the inlet model was established, which was confirmed by the schlieren picture and analysis of test data. The subsonic combustion supersonic inlet experiment can be carried out in hypersonic pulse wind tunnel, and the constraint conditions are smaller; moreover the inlet model can be designed lager in the pulse wind tunnel; the control method of exit parameters of inlet test in conventional wind tunnel experiment can also be used in pulse wind tunnel; The precision of the inlet internal flow test data was equivalent to which was obtained from conventional wind tunnel. The new thermal environment prediction method of cruise missile with circle inlet was developed based on the fluid structure analysis and experimental results.A set of integrated methods of air inlet test and a method of data analysis in pulse wind tunnel has been explored, it will be beneficial to the air inlet test in the pulse wind tunnel in future.