Abstract
A flow visualisation technique has been used to determine the pattern of flow behind bluff bodies in a square duct. A V gutter with closed base, a square prism and a cylinder have been used as bluff bodies, all the bodies having the geometric blockage of 37.5%. The flow patterns have been obtained using oil flow visualisation technique for inlet velocities of 10, 15, 20 and 25 m/s. From the flow patterns obtained, the geometry of the recirculation zone formed behind the bluff bodies has been determined. The method is very useful in determining the geometry of recirculation zone formed behind bluff bodies accurately in two-dimensional flows. These studies have extensive application in combustion research to find the effectiveness of bluff bodies. Moreover, flow pattern informations can be used to validate numerical methods used for the prediction of recirculating flows.
