Performance Study On Heat Transfer And Pressure Drop Of The Radiator And Intercooler Of Commercial Vehicles

The ribbon-tubular heat exchanger has been widely used in many kinds of vehicles and engineering machinery especially in commercial veciles in recent years. Due to the influence of louvers on the fin and offset strip fin inside the tube, the disturbance of fluid is enhanced effectively, the thermal boundary layer is destroyed, and the effect of heat transfer is improved effectively so that it's difficult to predict the heat transfer and flow resistance, which makes the develop of new radiators hard. So I try to establish a math model of the heat transfer and flow resistance characteristics of ribbon-tubular radiator and intercooler which can make predictions.In this thesis, the louvered- fin in air side of radiator was built based on experimental data and basic theory of the heat transfer, which uses the method of multiple linear regression. The model including heat transfer factor j and the friction factor f which are about Reynolds number Re, wave height HH and wave distance Lp, which is multivariate exponential form. Applying this mathematical model to another type of radiator which has similar structure in louvered-fin to make verification and modify. Then we apply this modified mathematical model to a version of louvered- fin intercooler for building the model of a hot air channel unit model with offset fins inner the tube. Based on the connection of radiator and intercooler which have similar structure of louvered- fin, this paper develops the mathematical model of complexity structured louvered- fin and a hot air channel unit model with offset fins inner the tube, which supply a direction to study the numerical simulation analysis of radiator and intercooler.The relationship between heat dissipation, pressure drop and water flow, air speed is found. Heat dissipating capacity in both of water and air side will increase with the raise of air speed and water flow, vice versa. There has been a faster change when air speed verified. The resistance of air is influenced by the air speed totally which has a positive correlation means that the resistance of air increase with the augment of air speed. The resistance of water is influenced by the water flow thoroughly which has a positive correlation between them.