Flow and Heat Transfer Characteristics of Surface-Mounted Cylinder in Presence of Rectangular Winglet Pair

Heat transfer and flow field characteristics past surface-mounted finite height circular cylinder in the presence of vortex generators (VGs) have been investigated numerically. Aspect ratio of circular cylinder such that the ratio of height to diameter of cylinder is kept fixed as 2.0 and Reynolds number based on diameter of cylinder and free stream velocity has been varied in the range from 1000 to 4000. Vortex generators in the form of rectangular winglet pair (RWP) in common flow down configuration with an angle of attack equal to 35° are considered for the present study. Present study aims to investigate the effect of combination of finite height cylinder and RWP on heat transfer enhancement by varying location of RWP relative to center of the cylinder. To illustrate the behavior of flow field, streamlines plots have been used and are compared with heat transfer field by using temperature contours. Pressure loss and heat transfer enhancement are quantified in terms of friction factor and overall surface-averaged Nusselt number, respectively. The concept of secondary flow intensity has been used to estimate the relationship between heat transfer and secondary flow. Effect of RWP location on thermal performance factor has also been reported.