Study On Detonation Sensitivity Of Gasoline Engine Based On Piston Head Morphology

Under the dual pressure of environment and energy.The engine combustion process requirements are getting higher and higher.Supercharged miniaturization is one of the important ways of energy saving and emission reduction.But with the compression ratio increased,inevitably produce knock.Knock will cause irreversible damage to the engine and reducing the fuel combustion efficiency.Studies have shown that the internal shape of the combustion chamber has a great influence on the combustion process.This paper combines the causes of gasoline engine knock,detonation suppression scheme,detonation detection method and knock simulation method and the study of engine combustion chamber morphology.Using the combination of engine test and numerical simulation to design different piston morphology.Study the sensitivity of different piston morphologies to detonation.Optimized to obtain a low detonation sensitivity piston.Proposed a more intuitive evaluation of knock strength calculation method for simulation.And its rationality was verified.Under the premise of systematically understanding the relevant theoretical basis of numerical simulation of internal combustion engine.The prototype maneuvering WH125-6 engine was tested and the GT-Power simulation model was constructed according to the layout of the engine gantry.Compare the test and simulation data,verify the accuracy of the original one-dimensional model.And then the numerical simulation of the engine model with 9~14 compression ratio and 2000~6000r/min speed.Comparison of different programs Engine effective torque and knock strength.Determine the speed and compression ratios for detonation sensitivity studies.Through the three-dimensional modeling software CATIA reverse construction of the engine three-dimensional model.The model is processed using CONVERGE software.According to the results of the original engine test and the one-dimensional simulation.Set the boundary conditions and the relevant model parameters,comparative test and simulation results.Verify the accuracy of the model and parameter settings.Based on the one-dimensional simulation to determine the speed and compression ratio,The establishment of the same compression ratio of different piston shapes.Under the same conditions,this paper carries on the numerical simulation of different form piston engine.Analyze the sensitivity of different piston morphologies to detonation.Presents a method of knock strength evaluation methods for simulation,and verify the rationality by comparing with the existing detonation evaluation method.Verified the rationality by comparing with the existing detonation evaluation method.Through the construction of the method to evaluate the sensitivity of different topography on the knock.And the results show that the hypersensitivity scheme is consistent with the simulation results.