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.

A Review of Aerodynamics Influence on Various Car Model Geometry through CFD Techniques

“…A significant increase of pressure contours in front of the model is due to the result of high-velocity acceleration, parallel with Bernoulli's principle when the high-pressure area corresponds with the low-speed area of the speed profile [69]. Research by Samy et al, [22] further indicates that the front model represents the high value of static pressure whilst pressure drop is experienced at the back and under the body of the vehicle which affects drag and lifts coefficients as exemplified in Figure 14 [22]. Major pressure reduction can be seen on the roof of the TATA Safari model due to the low-velocity acceleration as compared to the Ahmed model (the simple bodies).…”

“…This model can be divided into a few categories such as TATA Safari, TATA Nano, and TATA Indica. The findings of literature reviews revealed that Samy et al, [22] applied the TATA Safari model for the SUV segment with the length (L) of 4655 mm and the width (W) of 1855 mm [22]. The angle of the windshield is 32° and it is located 100 mm from the centre of the front wheel as shown in Figure 6.…”

“…6. TATA Safari model used by Samy et al, [22] Figure 7 illustrates research by Ansari [17] that utilised the TATA Indica model by importing sketches involved with blending 2D or 3D curves and rendering to produce realistic images. This model can be classified as an A-segment vehicle and compact car.…”

“…1. Element of the net forces for vehicle [15] Previous findings have annotated that the shape of car model geometry is important and varieties of vehicle design have been applied in both experimental and numerical studies [1,4,12,[22][23][24]. These shapes can be classified into three categories namely simple bodies, basic car shapes, and production (series) cars [24].…”

Flow Structure Characteristics of the Simplified Compact Car Exposed to Crosswind Effects using CFD

“…The previous findings have explained that the difference in vehicle model geometry is important and varieties of vehicle designs have been used in experimental and numerical research [14]- [17]. Based on Samy et al, the study on the aerodynamic analysis without crosswind involving a Sport Utility Vehicle (SUV) focusing on the drag and lift coefficient [17].…”