Numerical analysis of drag and lift coefficient of a Sport Utility Vehicle (SUV)

Abstract

The paper describes the modeling and analysis of a Sport Utility Vehicle (SUV). The present study mainly focuses on the reduction of aerodynamics drag and lift coefficient of a car, which helps to improve the vehicle performance and fuel efficiency. Usually the aerodynamic drag and lift is insignificant at low vehicle speed but the magnitude of air resistance becomes considerable with accelerating the vehicle. The Computational Fluid Dynamics (CFD) helps to analyze the flow stream around a SUV. The modeling software is used to design a 3D car model and the flow stream is analyzed by ANSYS Fluent. Initially, the first model was analyzed at various velocity conditions using Reynolds-Averaged Navier-Stokes (RANS) with standard k-ϵ model. The basic model of SUV has a drag coefficient and lift coefficient value of 0.62 and 0.099 respectively. Initially the first model is designed by introducing air splitter on roof and based on the results the second model is designed by introducing 15 degree boat tailing angle with first model. The drag reduction is reduced by 6.45% for first model and 19.35% for second model compared to the base model. Similarly, the lift coefficient is reduced by 2.02% for first model and 30.30% for the second model. Moreover the second model produces low drag and lift coefficient than first and base model. A significant reduction is observed in first model when compared to the base model. The vector plots are used to examine the streamline path of both the models.