Analysis And Simulation Of Matching Diesel Engine Cooling Water Jacket

The cooling medium flow conditions directly affect the quality of the diesel enginecooling performance of the cooling system, the number of each component part of the size ofthe heat load of the diesel engine heat distribution box, especially for high strengthen eachcylinder multi-cylinder diesel engine cooling performance uniformity research, not only to theengine power output and fuel economy is good or bad, but also to the reliability and durabilityof the diesel engine. So diesel engine cooling problem has always been the core point ofconcern designer.Thesis using CFD methods to calculate the model set for incompressible flow field,turbulent flow containing heat transfer, simulation turbulence model used in the process, theuse of diesel engine cooling high precision second-order discrete methods and SIMPLEmethod for a particular model system, cooling water flow and heat transfer simulationcalculations, first using parametric modeling to establish the actual size of the cooling waterjacket diesel model, the use of meshing software for model meshing. The test modelcalculations based on previous experimental data and theoretical set of initialization andboundary conditions, obtained by simulation flow distribution of cooling water jacket coolant,wall heat transfer coefficient and pressure distribution etc.By the results were analyzed to testprototype found deficiencies exist and the corresponding portion of the improvementprogram.Using the same boundary conditions and initial conditions were improved modelsimulation, the results obtained with the original model results were compared, improved afterthe diesel engine water jacket overall pressure loss32.7KPa, bridge of the nose area of thecooling water flow rate increased to1.1m/s or more, to ensure that the cooling key domains,the average of the overall HTC for7270.5（w/m2k）, and is distributed more evenly, to meetthe diesel engine cooling requirements. Diesel engine coupled to the improved heat transferanalysis results: affected by exhaust heat of the exhaust path around the water jackettemperature is higher than the intake water jacket, head water jacket temperature range of70℃-279.1℃; the composition of the combustion head room temperature within the range ofhigher average temperature is about280℃, the maximum temperature of324.5℃, testprototype material for ductile iron cylinder head can withstand a maximum temperature of375℃, so the temperature range of models to meet the technical requirements; the averagetemperature of the body about85℃, which with the cylinder head, piston liner compositionwith the highest part of the temperature of the combustion chamber, and its value is248.2℃,the liner material is EMS2alloy cast iron, with an average temperature of each cylinder in thematerial can withstand temperature range. Through computational analysis have been moreaccurate simulation results for an internal combustion engine cooling study provides a theoretical basis.