Simulation and Experimental Study of Large-Angle Spray Collision of Double Injectors
In order to increase the liter power of the diesel engine,High Power Density(HPD)diesel engine adopts dual fuel injectors.However,in a high-temperature environment(1200 K),the excessive amount of fuel not only increases the combustion equivalent ratio but also shortens the lag period,so that the fuel begins to ignite before it is fully atomized,resulting in combustion deterioration.Organizing spray collision can promote oil-gas mixing and alleviate the deterioration of combustion to a certain extent.The current research on collision spray is characterized by small collision angle and mainly aimed at spray atomization.In order to further improve the com-bustion efficiency of ultra-high power density diesel engine,the atomization and soot generation characteristics of large-angle collision spray(90°,120°,150°,180°)of dual injectors were explored based on the visual constant volume combustion bomb,and the spray collision was simulated by Star-ccm+software.It was found that the ki-netic energy loss of spray collision at any angle can be predicted by the kinetic energy loss of 180° collision spray,based on which a kinetic energy loss model of spray collision is proposed.The experimental results show that with the increase of collision angle,the turbulent kinetic energy of the spray area increases,both the atomization and the combustion quality are improved,the peak value of soot decreases,and the oxidation rate of soot accelerates after the collision.
spray impingementhigh-temperature conditionturbulence kinetic energykinetic energy loss modelconstant volume combustion chamber