The Flow Field Analysis And Parameter Optimization Of Compressor Blade Cleaning

In the aero-engine working process,the smog,salt and other suspended particles in the air can be inhaled into the engine.These particles attached to the compressor blades and walls will lead to form fouling,which on the gas path components will reduce the efficiency of engine working,lead to the engine fuel consumption increased,in severe cases,will may cause surges,engine air parking and so on.The aero-engine online washing is a kind of effective method to remove fouling,however,domestic scholars have less research on the mechanism of the fouling removal,and have a shallow understanding of the transport properties of the cleaning fluid and the cleaning flow field.Therefore,in this article,the compressor blades cleaning flow field is researched and the optimization parameters of the cleaning flow field are carried out in the online cleaning experiment.In this paper,the compressor flow channel model was obtained based on three-dimensional measurement,using the Euler method to numerically research the flow field of compressor blades,then the model of the action of atomized droplets on the compressor wall fouling was established,and the influence of atomized droplets on the cleaning flow field was analyzed by using the discrete phase model.Finally,the online cleaning effect of compressor blades was studied by experiments.The paper mainly carried out the following work:Firstly,the kinetics analysis of the cleaning flow field and the model establishment of the compressor flow channel.Taken the CFM56-7B engine as the research object,the moving blade carrying three-dimensional measurement was measured by the non-contact stereoscopic parallax method and reversed.The three-dimensional measurement of the radius of the inlet and outlet hub wall and shroud wall of the low-pressure first-stage moving blades were carried out to obtain a real compressor flow channel model.Secondly,the cleaning flow field of compressor blades was numerically studied.Calculate boundary conditions in different situations and complete grid verification.The influence of jet parameters and cold-rotation speed on the static pressure,velocity and vorticity of the cleaning flow field were analyzed.It is found that increasing the jet pressure can improve the cleaning effect,and increasing the cold-rotation speed can enhance the cleaning fluid transport capacity.By optimizing the cleaning parameters,the optimal jet parameters and the cold-rotation speed are obtained.Then,the effect of atomized droplets on cleaning effect was studied.Firstly,the movement behavior of the droplet impacting the compressor walls was analyzed in order toobtain the criterion of whether the droplet was splashed.Then,establish the shear-positive stress model of the droplet impacting the compressor walls which were theoretically analyzed.Finally,the discrete phase model was used to further analyze the influence of droplet size and cleaning fluid mass flow on the cleaning flow field,and the optimal particle size range and the ratio of cleaning fluid to air mass flow are obtained by parameters optimization.Finally,an experimental research about the aero-engine online washing was carried out.The new equipment was used to clean the engine and compared it with the cleaning effect of the old equipment.The experiment proves that the cleaning effect of the new equipment can better meet the airline requirements.