Research On Simultaneous Measurement Of Acetone PLIF And OH-PLIF In Methane Air Flame

With the progress of science and technology,aviation engine is developing towards improving the performance of itself.While improving the fuel combustion efficiency,it will try its best to reduce the pollutants of the combustion.Engine working process contains several steps,including injection,atomization,evaporation,mixing,ignition and combustion.The mixing of fuel and oxidant will impact the combustion process.The condition of mixing will directly affect the efficiency of combustion.Therefore mixing in engine working process is also an extremely important step.And the temperature change during the burning may also cause influence on the mixing process of fuel and oxidant.Therefore,this paper proposes a method for simultaneous measurement of methane air flame mixing and combustion process based on Planar Laser Induced Fluorescence—PLIF.For the mixing process of methane and air,tracer particles should be added to one of the gas.The fluorescence effect of tracer particles is used to represent the mixing process of fuel and oxidant.Acetone is selected as the tracer particle of the gas in the experiment.As the combustion intermediate in the combustion process,the hydroxyl radical(OH)can be selected as the tracer particle of the combustion field to represent the structure of the combustion flame.The absorption spectra and fluorescence spectra of acetone and OH are investigated by experiment and theoretical simulation.Based on the planar laser induced fluorescence technology,a method for the simultaneous measurement of acetone PLIF and OH-PLIF in methane air flame is proposed.An experimental platform for synchronous measurement of acetone PLIF and OHPLIF was built.A set of laser output equipment and a detector were used as experimental devices.In this paper the change rule of acetone fluorescence signal intensity with concentration and temperature under normal pressure is explored,the stability of acetone carrying amount in gas obtained by bubble method is studied,and the gas mixing uniformity of burner is analyzed.The structural differences between the cold flow field and the combustion flow field are studied to explore the interaction between the combustion and flow field.The simultaneous measurement of acetone PLIF and OH-PLIF is applied to the diffusion flame produced by burner.Compared with the results getting from step by step in the combustion field,the structural similarity of the flame synchronous measurement results is 93.12%,PLIF images of flow field and combustion field generated by nozzles of near real rocket engines are obtained.