Flow structure investigation of a Volvo S60
Examensarbete för kandidatexamen
Maskinteknik 300 hp (civilingenjör)
Reducing aerodynamic drag is a major goal in vehicle design and the positive impact of reduced drag on fuel consumption is well-documented. Drag is influenced by the physical phenomena around a passenger car. It is thus imperative to better understand the flow structures on a passenger car. This study investigates the flow structures occurring on the rear of a Volvo S60, conducted in STAR-CCM+. The flow structures were observed for varying Reynolds number, varying yaw angle and with and without an antenna. The results show that the pressure coefficient and skin friction coefficient change slightly at different Reynolds numbers. How they change depends on where on the vehicle the coefficients are analyzed. The varying yaw angle impacts the pressure coefficient and the skin friction coefficient by shifting the structures away from the direction of the flow. The antenna case shows that the flow is disrupted by two opposing vortices which impact the pressure coefficient and the skin friction coefficient. The skin friction coefficient and pressure coefficient changed with the velocity but this did not have any apparent effect on the drag coefficient. For the yaw angle study it was the other way around; all three parameters changed with an increase in yaw which thus meant that the flow structure on the car had a yaw angle dependency. The antenna showed a distinct alteration of the flow structure. An increase of skin friction in line with the antenna was detected from the window to the end of the boot lid. Also an increase in pressure over the bottom of the rear window could be identified. However, the antenna did not affect the drag coefficient in any significant way.
Strömningsmekanik , Grundläggande vetenskaper , Hållbar utveckling , Transport , Fluid mechanics , Basic Sciences , Sustainable Development , Transport