Numerical Investigation of Drag Reduction Techniques in a Car Model

Abstract

Reducing the drag force has become one of the most important concerns in the automotive industry. This study concentrated on reducing drag through use of some external modifications of passive flow control, such as vortex generators, rear under body diffuser slices and a rear wing spoiler. The study was performed at inlet velocity (V=10,20,30,40 m/s) which correspond to an incompressible car model length Reynolds numbers (Re=2.62×105, 5.23×105, 7.85×105 and 10.46×105), respectively and we studied their effect on the drag force. We also present a theoretical study finite volume method (FVM) of solving Reynolds-averaged Navier-tokes equations (RANS) using a realizable k–epsilon (k-ε) turbulence model, conducted on a car, model KIA Pride, which is popular in Iraq and Iran. All computational analysis and modifications were carried out using the ANSYS Fluent 19 computational fluid dynamics (CFD) software and SOLIDWORKS 2018 modeller. The drag coefficient of the analysed car was found to be 0.34 and the results show that the drag can be reduced up to1.73% using vortex generators, up to 3.05% using a rear wing spoiler and up to 2.47% using rear under-body diffuser slices modifications, whereas it may be reduced up to 3.8% using all previous modifications together.

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

“…The compact car model was imported and modified in CATIA by neglecting the tires, and side mirror and exported in ANSYS Design Modeller as shown in Figure 2. The purpose to neglect some of the external parts is due to the limitations in the simulation technique [18], [19] and to avoid the effect of rotational motion and tires wake [20]. Based on the study by Han et al [21], the simplified Aerodynamic Studien Model (ASMO model) is applied due to the actual model of the car body generally having sophisticated surfaces and part specifics.…”

“…The computational domain is chosen to extend two vehicle lengths (2L) in front of the vehicle and three lengths (3L) behind the rear of the vehicle on the x-direction. The distance behind the car should be sufficient to allow fluid flow without interfering with the flow of air in the outlet section [20]. The distance of the vehicle from the side is selected to enlarge five vehicle lengths (5L) for the both left and right of the car on the y-direction.…”

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

“…These models have the proportions of production cars, but possess disentangled and streamlined surfaces. The basic car shapes consist of few external parts such as side mirrors and it is used for testing, validation, and research [58]. The example of basic car shapes illustrated in this review paper is classified into two, namely Motor Industry Research Association (MIRA) model and the TATA model.…”

“…Nevertheless, these models cannot produce smaller processing data and more systematic changes [24]. There are few examples of production (series) cars geometries applied in the previous studies namely KIA Pride, Swift Dzire, Volvo, Hybrid Electric Vehicle (HEV), and Range Rover models [23,58,63,64].…”

“…9. The Swift Dzire model applied in computational analysis by Dias et al, [23] Saleh and Ali [58] further performed the production (series) cars, KIA Pride model by ignoring the side mirrors, grilles, exhaust, tires without rotational motion and no solid contents as illustrated in Figure 10. The KIA Pride model has full-scale car dimensions for a small passenger car with a length (L) of 3935 mm, height (H) of 1455 mm, and width (W) of 1605 mm.…”