Effects of heating on turbulent flow behavior over rough surfaces

Particle image velocimetry (PIV), an established flow measurement technique in the field of experimental fluid dynamics, uses high speed cameras to capture positional data of laser-illuminated tracer particles. From such data, instantaneous and average velocity fields, along with other derived quantities, may be obtained in order to study flow behavior under different scenarios. Using two-dimensional PIV in the Union College wind tunnel, we investigated the effects of localized heating on a turbulent boundary layer over 2D k-type circular roughness elements. Flow quantities were compared for a single element at room temperature and heated to 170°C. Results indicate that heating increased vertical velocity directly upstream of the element and decreased horizontal velocity in the downstream wake. These findings suggest the presence of local buoyancy effects driven by elevated fluid temperatures near the heated surface.