Flow visualization techniques for full-scale test objects in a wind tunnel: Evaluation of a novel flow visualization technique

Sammanfattning

Accurate flow visualization in wind tunnels is essential for aerodynamic optimizationand CFD validation. Traditional qualitative methods such as smoke and tufts offerquick insights but lack quantitative precision. Conversely, techniques like LaserDoppler Anemometry (LDA) and Particle Image Velocimetry (PIV) provide detailedflow measurements but involve complex setups and pose safety concerns due tohigh-powered lasers. This thesis identifies the ProCap system as a measurementsystem that bridges this gap by providing qualitative and quantitative informationwith relatively low complexity. ProCap measurements around a full-scale car in acommercial wind tunnel are compared against an existing pressure-based traversegearsystem and CFD simulations. The findings show that ProCap is not sufficientlyaccurate or consistent for CFD method validation, but can be a valuable tool whenevaluating vehicle designs by identifying separated regions and overall flow topology.