Investigation of the effects of rear window angle and spoiler design on aerodynamic characteristics of a sport utility vehicles

When designing a vehicle, first of all, handling, fuel economy and aerodynamic features of vehicle performance are considered. Road vehicles are exposed to certain effects during their movements. Vehicles under the influence of drag and lift forces, yaw, pitching and rolling moments and many more cannot show the desired performance. The shape and design of the vehicle play a major role in the effects it will be exposed to. For this reason, the design of vehicles is being renewed and changed day by day. The sharp-edged structure of old vehicles is not present in today's vehicles. In order for the vehicles to be affected by the negative effects caused by friction and lifting forces in the least way, shaping is done to reduce these effects as much as possible during the design. Every vehicle is designed in accordance with its intended use, it is tried to be produced in a way that will exhibit the best performance and at the same time provide fuel savings. In the scope of this thesis study, spoiler design and rear window angle for a sport utility vehicle have been numerically analyzed under aerodynamic effects. The study was carried out three-dimensionally using ANSYS-Fluent software. The vehicle was modeled and analyzed at a scale of 1:10. The variables of the study were determined as spoiler length, spoiler angle for fixed spoiler length, and rear window angle for fixed spoiler. The results obtained show that the spoiler length significantly affects both lift and drag coefficients, while the spoiler angle also has a considerable impact on these two significant coefficients. With this result, it has been shown that vehicle road holding and fuel consumption can be controlled with spoiler design. In addition, in the study conducted for the rear window angle, it has been shown that changes can be made in the vehicle's interior volume, especially considering the drag and lift coefficients.