School of Mechanical Engineering Tamar Domb
School of Mechanical Engineering Seminar
Wednesday, May 15, 2019 at 14:00
Wolfson Building of Mechanical Engineering, Room 206
Active and Passive Flow Control Methods Applied on a Quarter Truck Model
Tamar Domb
M.Sc. student of Prof. Avi Seifert
The need to reduce the fuel consumption of road vehicles, in particular of heavy ones, is an important scientific and technological challenge, due to its economic, environmental and political impact. Driving at highway speeds is a highly wasteful process, because the aerodynamic drag (airflow resistance) is increasing in a cubic fashion with the driving speed.
The present research deals with advanced methods to reduce the fuel consumption of heavy vehicles driving at highway permitted speeds. The research went beyond the currently available methods, that are passive (e.g., shaping) that modify the shape of the trailer end. Our methods are termed “active” in the sense that they use a system of devices that consume energy, but can be operated only when needed and in a controlled method that can be adjusted to the changing driving conditions and more importantly, be significantly smaller than current devices while being at least as effective.
The main goal of the research was to study the effects of the shape of a drag reducing device, that is mounted at the rear-end of a truck-trailer configuration, and mapping the stream-wise vortices that develop at the corners of the drag reducing device.
The model used in this research is a quarter model of a 1:6 scale of a real truck, mounted to two of the wind tunnels walls. The experiments included a few main configurations, and the baseline configuration. Passive flow control methods were added in the form of add-on devices mounted to the model's back wall. One add-on device was also used with two methods of active flow control: Flow suction and a combination of flow suction with oscillatory blowing.
The wind tunnel test results showed drag reduction using the add-ons, which in some cases was increased thanks to the active flow control methods used. The most effective combination was detected and a net gain calculation was made.
