Paper Title
Investigation of Different Turbulance Models on Thermal and Hydraulic Behaviour of Automotive Cooling System

Abstract
Various turbulence models have been developed in the past years. All of these turbulence models can be used for heat transfer problems. Nevertheless it is not appropriate to use every turbulence model in every problem. In this study, five different turbulance models (Standard k-e, RNG k-e, Realizable k-e, Standard k-w and SST k-w) were used to obtain heat transfer and pressure drop values in automobile radiator. Solutions which were attained from different turbulence models were compared with the experimental data to determine the most suitable turbulence model for automobile radiators that is a compact cross-flow, water to air heat exchangers. Heat transfer and pressure drop characteristics of the automotive cooling system were numerically investigated using Ansys-Fluent with three different air velocity (8.33, 13.88 and 19.44 m/s). Both coolant and air flows were considered as turbulent, steady and incompressible. For each turbulance model and air velocity, the outlet temperature of the coolant, heat transfer rate of the radiator, water and air side pressure drops were obtained. Index Terms - Turbulance Models, Computational Fluid Dynamics (CFD), Automotive Cooling System, Pressure, Heat Transfer