Numerical Simulation Research On Automobile Engine Cabin Thermal Management

Engine is the core to vehicle power performance, fuel economy and emissions performance, the objective demand of energy, environment and artificial make car engine running control standard is getting higher and higher. A comprehensive measure-Vehicle thermal management is proposed in this background. Based on National Science and Technology Support Program,-"Development of Commercial Vehicle Parallel Hybrid System" and university-enterprise cooperation project "Calculation and Thermal Management Analysis of Commercial Vehicles and Bus Power System", flow and heat transfer conditions in engine cabin was studied on two different vehicles.This paper analyzed the needs and the purposes of vehicle thermal management, according to the requirements, boundary conditions was obtained based on experiment and numerical simulation. And then one dimensional thermal management simulation was performed.Based on the CFD theory and requirement, combined with the actual conditions of computing resources, assumptions and simplifications were applied to the thermal management. Based on assumption and simplification,3d numerical model of bus, truck, were established, and simulations were performed on the standard k-ε turbulence model. One dimensional simulation and the car body structure were improved based on the numerical simulation results.On the basis of3d numerical model, Standard k-ε model, RNG k-ε model, realizable k-ε model, the shear stress transport model (SST k-ω) and two correction model of RNG k-s model-viscosity modification and swirl modification were used to completed the simulation, then compared their performance and applicability in the simulation. Through comparison, we found that the realizable k-ε model is most suitable for the simulation, and both of the two correction model of the RNG k-ε model, Can improve the calculation accuracy.This paper analyzed the spatial distribution characteristics of the heat radiator’s thermal, and take the average volume heat source’s disadvantages in model3d thermal distribution in to consideration. Non-uniform heat source method and DUAL unit model have been proposed. And the calculation results showed that two kinds of calculation method can both improve the spatial distribution of heat condition. And this provided reliable improvement to study the influence of the spatial location effect on the cooling radiator.