VORTEX GENERATION IN FLOWS PAST DIFFERENTIALLY DIMPLED SURFACES

The results of visualization of vortical water and air flows past surfaces with various dimples (trench-like, semispherical, and cylindrical) for heat transfer intensification in laminar, transient, and turbulent regimes are presented. Flows past single dimples and their systems were investigated. Various methods of visualization were used such as smoke, the carbon oil, and coloring admixtures. Flow pictures and flow pattern diagrams on the surfaces with various dimples are given. Comparative results of infra-red investigations of convective heat transfer on surfaces with such intensifiers are presented. The mechanisms underlying heat transfer intensification on such surfaces are defined. Optimum design parameters of such heat transfer intensifiers are recommended.