Abstract
Road vehicles such as passenger cars, trucks and SUVs are categorized as bluff bodies. As a vehicle moves forward, the motion of the air around it produces pressure gradients, which vary across the entire body surface. This in turn helps to develop a turbulent wake region behind it, which works against the vehicle’s forward motion. As a result, the engine has to work harder, thus increasing fuel consumption. The purpose of this thesis is to present development, design and optimization of drag reducing devices for SUVs by examining the SUVs aerodymanic properties. Simulations using commercial software such as Solidworks, Ansys Workbench, Design Modeler, Mesh Editor and Fluent were performed to study the aerodynamic behavior behind the SUV. The Ahmed Reference Model (ARM) was selected as a benchmark test. Computational fluid dynamics (CFD) simulations for three SUV models were performed and their performance was analyzed to determine which design yields the best drag reduction results. The three CFD models consist of one basic SUV model without any drag reducing devices. The second one uses a bump-shaped vortex generator (VG) design and the third one uses a delta wing VG design. Out of the two VG designs, it was determined that the bump-shaped design yielded the best drag reduction results for the SUV model. The next step was to experiment with the VG height to determine the optimum height for the SUV model. Results demonstrate that a bump-shaped VG with a height of 25 mm yields the lowest CD.