Research On Underhood Thermal Management Technology

With the rapid development in automobile industry, the requirements forcar safety, comfort, energy saving and environmental protection are alsoincreasing. Today’s car tends to be designed to streamlined and lower body.This leads to relatively narrow engine compartment space and more compactcomponent placement and results in overheat underhood environment. Heatexchangers’ performance deterioration has seriously affected the performanceof automobile engines which directly affect the car’s economy, power andsecurity. Resorting to a highly efficient and reliable Underhood ThermalManagement (UTM) technology is imperative.Based on a real car model, a mathematic model of the vehicle UTM isestablished to simulate the airflow and heat transfer in the underhood. At thesame time, one-dimensional mathematic model of the engine system and thecooling system are built. In3D model, the radiator is represented with anequivalent pressure loss model, and the moving and discontinuous elementsare applied for the computational fan model. The results of theone-dimensional simulation for the engine and cooling systems and theexperimental characteristic curve of the radiator are used to decide theboundary conditions of the three-dimensional simulation. Based on thethree-dimensional results, the input parameters of the one-dimensionalsimulation are modified. Repeat of the modifications is defined as1D/3DCoupling UTM Simulation. The coupling analysis is obtained to guide theoptimization of the whole vehicle thermal management.In this paper, defined1D/3D Coupling UTM Simulation solved the problem that empirical data is not enough reliable and experimental data isnot enough comprehensive through an iterative modifying the parameters.Because of enough consideration of the structure and overall layout of thedesign components in calculation, the numerical simulation conditions arevery closer to the fact. This paper provides an analysis platform for the wholevehicle thermal management study and a foundation for optimal design beforemanufacturing the prototype.