Video 2 shows a heat transfer experiment for flow over a flat plate with a rib of square crosssection placed closer to the upstream corner. The plate (seen in a plan view) is pasted with a liquid crystal sheet. The plate is also initially heated and at a uniform temperature. Hence, the liquid crystal sheet appears blue. The experiment is started when air flow (from left to right) is initiated. The incoming air temperature is lower than that of the heated surface. At the same time, the heater connected to the flat surface is turned off. Under the influence of air flow, the surface cools with time. Owing to the formation of a thermal boundary layer, the cooling rate closer to the leading edge is faster than that to the right. The presence of the rib disrupts the hydrodynamic boundary layer, leading to vortex generation downstream. The vortex is also transported with the main flow. Hence, the heat transfer rates just downstream of the rib are very large and the plate cools very rapidly. This is seen from the red color that appears rapidly in this region. Elsewhere, the plate cools at a modest pace. In any case, the overall heat transfer rate for the plate with a rib is much greater than one without a rib (shown in video 1).