Designed and conducted a wind tunnel experiment for ME 30801 Fluids Lab to test drag reduction effects of vehicles tailgating semi trucks. The test setup utilized 1:50 scale 3D-printed models in a low-speed open-circuit wind tunnel.
Variable separation distances were tested from 0.75 to 5.75 inches (representing 3-24 feet at full scale) at wind speeds of 40, 60, and 80 MPH to simulate highway conditions. A threaded rod mounting system allowed precise positioning of the passenger vehicle while the truck was secured to an adjustable ground plate. The data analysis revealed significant drag coefficient reductions (up to -0.27) when following closely behind the truck, with stronger slipstreaming effects at higher speeds.