Numerical Analysis And Optimization On Underhood Cooling Characteristics Of Automobile

The numerical analysis on underhood cooling includes the performance ofcooling package and the airflow characteristic of underhood, which are the key factorsinfluence the driving stability, dynamic characteristics, and fuel economy. Along withthe development of automobile technology, and customer pursues safer and morecomfortably as well as for higher powered engines result in more tightly packedengine compartments, The numerical analysis on underhood cooling has become oneof the important and hardy problems in the field of Computational Fluid Dynamics.The time of starting in Basic research for the investigation on underhood coolingis very late, and research on key technique of aerodynamics is lack of in-depth study.This paper has carried out detailed research into performance of heat exchange andairflow of underhood field. Analysis of the results can give a beneficial basis for cardesigning, and finally coming to being a completely integrated method for designingof underhood thermal management will greatly promote research-independent andinnovation ability of our country’s automotive industry.A mathematical approach is developed to analysis the complex airside flow ofunderhood and external, which is used to investigate the airflow characteristic andtemperature distribution of underhood at the vehicle conditions: high speed, torque,power, idle.Through analyzing the reason of temperature distribution to estimate thecapability of cooling.Secondly, consider the influence of solar radiation under three different momentson the temperature field in the underhood, provide a theoretical basis for if or notthe underhood need to be protected against solar radiation, followed by,comparativeanalysis three different road such as asphalt, cement, sand the influence of theirthermal radiation on temperature field in the underhood under the extreme hightemperatures.Then, based on the airflow characteristic and temperature distribution ofunderhood, realizing the improvement of the underhood cooling,through improve thefront-end into the gas design parameters, optimization the flow field in the underhoodand block the thermal radiation of high temperature components. At the vehicleconditions, the air flow of radiator, intercooler and condenser, increased by4.43%，5.51%，4.61%; intercooler outlet side temperature decreased6.2℃, radiator outletside temperature decreased6.5℃, condenser outlet side temperature decreased6.5℃;the highest surface temperature of engine sump tank decreased20.6℃. Finally, an agent-based modeling approach is developed to optimize the hole size,location and mounting angle of the deflector of the engine guard shield. The optimalresults calculated by Multi-island genetic algorithm show that the cooling air flowmost increased by1.94%.This provides a reference to thermal management by theresult of the numerical simulations.