Author's School

School of Engineering & Applied Science

Author's Department/Program

Mechanical Engineering and Materials Science


English (en)

Date of Award

January 2009

Degree Type


Degree Name

Master of Arts (MA)

Chair and Committee

Ramesh Agarwal


Drag reduction studies on generic truck models using passive shape optimization and active flow control are studied using numerical methods. A genetic algorithm is used to find optimal truck front shapes for reduced drag. The best shape found gives a 3.4% drag reduction. Active flow control is used to reduce drag by using oscillatory synthetic jet actuators on a generic truck body, a D-shaped bluff body, and the Ahmed body. Experimental data is available for these three configurations without and with active flow control. Actuators at the back of the trucks energize separating boundary layers and delay the shedding of low pressure-inducing vortices in the wake resulting in drag reduction. A maximum drag reduction of 16% and 21% was found to be possible for the two-dimensional model of a generic truck and a two-dimensional D-shaped bluff body respectively; these results are in close agreement with experimental data. Active flow control with steady blowing on the three-dimensional Ahmed body however did not show drag reduction. This calculation requires further investigation.


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