Thermal wake downstream of a three-dimensional obstacle

The temperature distribution within the thermal wake downstream of a three-dimensional obstacle mounted in a horizontal water channel is investigated. Temperature measurements are obtained at channel height-based Reynolds numbers of 500-1500 (laminar) and 10,000-25,000 (turbulent). Flow visualizations are used to elucidate the flow patterns in the separation region. The experimental results are compared with numerical simulations of the laminar flow field and thermal wake. In laminar flow, the wake temperature was found to increase with increasing Reynolds number and decreasing buoyancy effects. In the turbulent regime, the flow structures and measured wake temperatures were largely unaffected by the Reynolds number and buoyancy. The numerical models of the flow field were in reasonable agreement with the flow visualizations and with similar results in the literature. Reasons for the small discrepancies in the predicted and measured wake temperatures at the higher laminar Reynolds numbers are discussed.