Tail room for exhaust system of engine test bed

Abstract

The invention discloses a tail room for an exhaust system of an engine test bed, and the tail room comprises a big tail room and a replaceable small tail room. The big tail room comprises a tail room convergence segment, a tail room constant-section straight segment and a tail room expansion segment, wherein the tail room convergence segment, the tail room constant-section straight segment and the tail room expansion segment are connected together. The replaceable small tail room is disposed in the tail room convergence segment, and is connected with the tail room convergence segment. The tail room convergence segment, the tail room constant-section straight segment, the tail room expansion segment and the replaceable small tail room are respectively a hollow revolving body An engine with an engine tail jet pipe and the tail room convergence segment are disposed in a high-altitude simulation cabin, and the tail room expansion segment is disposed outside the high-altitude simulation cabin. The engine is an ultrasonic engine. The tail room provided by the invention improves the static pressure of a passive flow inlet of a subsequent air extractor, reduces the pressure ratio of the subsequent air extractor, reduces the number of ejectors of the subsequent air extractor or the volume of a vacuum tank, is provided with the replaceable small tail structure, and meets the demands of the testing of engines in various sizes.

Description

technical field [0001] The invention relates to a tail chamber for an exhaust system of an engine test bed, in particular to a tail chamber for an exhaust system of a supersonic engine test bed. Background technique [0002] When simulating the high-altitude flight state of the supersonic engine on the ground, the engine is usually installed in the high-altitude simulation cabin first, and the high-altitude cabin is evacuated with air extraction equipment so that the pressure in the high-altitude simulation cabin is the same as the environment at which the engine is in high-altitude flight. The pressure is the same, then the engine is ignited, and the high-altitude flight simulation test is carried out. During the test, the pressure in the high-altitude simulation cabin should always be kept the same as the ambient pressure at the altitude when the engine is flying at high altitude, which requires immediate discharge of the supersonic engine. The gas is discharged from the h...

AI Technical Summary

Problems solved by technology

[0002] When simulating the high-altitude flight state of a supersonic engine on the ground, the engine is usually installed in the high-altitude simulation cabin first, and the high-altitude cabin is pumped with air extraction equipment so that the pressure in the high-altitude simulation cabin is the same as the environment where the engine is flying at high altitude. The pressure is the same, and then the engine is ignited, and the high-altitude flight simulation test is carried out. During the test, the pressure in the high-altitude simulation cabin must always be kept the same as the ambient pressure at the altitude of the engine when it is flying at high altitude. The gas is discharged from the high-altitude simulation cabin. In the prior art, an ejector or a vacuum tank is usually used for pumping air, and the pressure outside the high-altitude simulation cabin is usually 0.11MPa, while the ambient pressure at the flying height of the supersonic engine is only about 100% of the atmospheric pressure. 0.1 times, or even 0.01 times, the boost ratio of the exhaust system should reach 10 to 100, and the flow rate of the corresponding exhaust system inlet is as high as ten kilograms or even hundreds of kilograms per second. The flow rate depends only on the pressurization of the ejector, and three to four stages must be connected in series. If a vacuum tank is used, the volume of the vacuum tank must be as high as tens of thousands of cubic meters. It can be seen that no matter whether the ejector or the vacuum tank is used alone as the pumping Air equipment requires a huge structure, which is not only inefficient, but also very expensive; secondly, the engine test bench usually needs to perform high-altitude flight simulation for various engines, and different engines, engine size, engine tail nozzle size, engine The outlet flows are all different, and a set of air extraction equipment cannot meet the test requirements of various engines

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