Aerodynamic Drag Reduction in a Passenger Vehicle Using Vortex Generator with Varying Yaw Angles: Detailed Study

Large investments are aimed at minimizing power needed for propulsion i.e., new downsized engines
with new aerodynamic devices for drag reduction. For passenger vehicles the aerodynamic drag force
is the dominating resistance force at higher velocity. The vehicle body is often optimized for reducing
the drag resistance. Vortex generators belong to the category of boundary layer manipulators. Their
function is to reenergize an adverse pressure gradient boundary layer that is about to separate by
transporting high momentum fluid from the outer part of the boundary layer down to the low
momentum zone closer to the wall. In this experimental investigation, the variation of pressure
coefficient, dynamic pressure, coefficient of lift and drag with and without vortex generators (VG) on
the roof of a utility vehicle have been studied at varying yaw angles of VG. The yaw angles used are
10°, 15° and 20°. To measure the effect of altering the vehicle body, wind tunnel tests have been
performed with 1:15 scaled model of the utility vehicle with velocities of 2.42, 3.7, 5.42 and 7.14m/s.
The experiments showed that a great improvement of the aerodynamic drag force reduction can be
achieved with vortex generator