The Truck Engine Compartment Research On Flow Field And Heat Dissipation Performance

With the development of the automotive industry, the engine components are increased and the space of under-hood is very crowd. All these factors have brought great pressure and challenge to under-hood heat transfer. With the development of computing hydrodynamics and computer technology, a numerical simulation technology is to be used to get the flow field and temperature field to evaluate the cooling performance of under-hood. Due to the advantage to decrease the automobile development cycle and R&D costs, numerical simulation technology has become the focus in the field of automotive aerodynamics research.This thesis is based on the background that a truck under-hood is overheating when taken a road test, a numerical simulation technology is used to analyze the engine compartment thermal environment. After identifying the cause and improving the under-hood structure, the cooling system is greatly improved.The thesis begins with simplifying the vehicle model, then establish the simulation domain, divide surface mesh and volume mesh by STAR-CCM+, discrete continuous simulation area, determine appropriate simulation conditions and boundary condition, establish some sub-models, such as porous model, heat exchanger model, fan model. At last, a simulation model of under-hood thermal management is established.Based on the flow field and temperature field, we can get some conclusion from the result. The prototype under-hood exists serious heat recalculation and has some high temperature area at peak torque condition, which is negative to the cooling of under-hood. The cooling performance of intercooler cannot meet actual requirement. Some improving measures are proposed by installing some plates around the radiator to avoid heat recycle and increasing guide plate area. After recalculation, the phenomenon of heat recycles disappeared and cooling performance of heat exchangers meets the actual requirement.Finally, test the temperature and velocity of the under-hood in the laboratory room and compare the simulating result with the experiment data. Comparison of the relevant result shows that the simulation model is essentially effective.