Research Of Ejector Lift Fan Based On Momentum Principle

Vertical/short-range takeoff and landing performance is of great significance to fighters,especially naval fighters taking off and landing on aircraft carriers,even as one of the criteria for future advanced fighters.At present,the main and relatively reliable vertical/short takeoff and landing scheme is to use lift fans with engine vector thrust.However,lift engine in the fuselage has some shortcomings,such as heavy dead weight,low efficiency,serious occupancy of aircraft interior volume,resulting in the reduction of fuel load and the sharp reduction of flight range.Under these conditions,it is of great significance to change the structure of lift fan,improve lift efficiency and reduce its weight and volume.The purpose of this paper is to find an ejector lift fan,which uses high-pressure gas to eject the outside atmosphere to increase thrust.The main research contents are as follows:1)Study the structural parameters affecting the ejection capability and thrust of ejector nozzle,by analyzing the flow field changes under different structural parameters to summarize the influencing rules and the optimize structure according to the relevant laws.2)Analyz the performance parameters affecting thrust,which is the ability of high-pressure working gas to eject the atmosphere and the gas mixing efficiency,by optimizing the flow field and the structural parameters,so as to improve the thrust enhancement effect.3)Study the method of reducing the profile size of ejector fan under the condition of specific increasing thrust effect to improve its practicability and economy.