Schlieren Visualization of Water Natural Convection in a Vertical Ribbed Channel

Schlieren techniques are valuable tools for the qualitative and quantitative visualizations of flows in a wide range of scientific and engineering disciplines. In this work, a schlieren technique is applied to visualize the buoyancy-induced flow inside vertical ribbed channels using water as convective fluid. The test section consists of a vertical plate made of two thin sheets of chrome-plated copper with a foil heater sandwiched between them; the external sides of the plate are roughened with transverse, square-cross-sectioned ribs. Results include flow schlieren visualizations and reconstruction of the local heat transfer coefficient distribution along the ribbed surface.