Scramjet engine directly connected test device capable of replacing free jet test and design method

Abstract

The invention discloses a scramjet engine directly connected test device capable of replacing a free jet test, which comprises a round-to-square section, a subsonic velocity S bending section, a Laval nozzle section, a boundary layer developing section, an air inlet inner channel simulation section and a boundary layer overflow exhausting channel. The scramjet engine directly connected test device is characterized in that a wind tunnel nozzle is enabled to deflect by a certain angle upwards, the angle is equal to a top plate compression angle in front of the lip of the air inlet inner channel simulation section, a flow parameter of an outlet cross section of the nozzle is enabled to be equal to a cross section parameter of the lip inlet of an actual air inlet, and an internal compression channel at the downstream of the lip of the actual air inlet is simulated directly. The boundary layer developing section is connected between the nozzle and the inner channel simulation section, and the lip of the nozzle and the boundary layers at two side walls are pumped through the overflow exhausting channel at an internal compression section at the same time, thereby being convenient to start the test device, and enabling the boundary layers at the upper and lower walls to display asymmetry similar to a real state. The scheme disclosed by the invention is high in simulation degree, a flow field structure in an air inlet throat and a downstream isolation section is authentically simulated, and a directly-connected test flow field is enabled to be closer to the flow field of an actual engine.

Description

technical field [0001] The invention belongs to the technical field of advanced intake and exhaust systems for aerospace vehicles, and in particular relates to a scramjet direct connection test device and a design method that can replace free jet tests. Background technique [0002] Research on the supersonic combustion mechanism and performance influencing factors is one of the core issues in scramjet research. In traditional research methods, experimental simulation research is the most intuitive and powerful means for scientific research. Traditional combustion chamber simulation tests are usually Including direct connection test and free jet test, but there are certain defects: [0003] In the free-jet test of the traditional scramjet engine, the inlet-isolating section is connected in front of the combustion chamber. If the size is too large, the corresponding nozzle outlet area will be larger, which requires the test equipment to have a considerable scale. At the same...

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Problems solved by technology

[0003] In the free-jet test of the traditional scramjet engine, the inlet-isolating section is connected in front of the combustion chamber. If the size is too large, the corresponding nozzle outlet area will be larger, which requires the test equipment to have a considerable scale. At the same time, a high-enthalpy wind tunnel that can produce the same flight conditions is required, so the energy consumption is large, the cost of the experiment is high, and the high-enthalpy The wind tunnel experiment time is short, which is not conducive to data collection and other work

[0004] The traditional direct-connection test is to directly connect the supersonic nozzle that produces a uniform flow field at the outlet with the combustion chamber. The direct-connection test has the advantages of simple equipment, low cost, and long test duration. There are many differences between the airflow of the combustion chamber and the airflow of the actual engine entering the combustion chamber from the intake port-isolating section

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