Experimental analysis of the heat transfer coefficient enhancement for a heated cylinder in cross-flow downstream of a grid flow perturbation

Passive techniques to increase heat transfer rate from a heated cylinder in cross-flow placed behind an obstacle are object of several numerical and experimental investigations. As widely reported in literature, combined effect of free stream turbulence intensity and local perturbations generated by the obstacle has a significant role to improve the convective heat transfer coefficient. Object of the present study is to analyze experimentally the effect of a particular perturbation grid, formed by two vertical strips, on the global heat transfer rate from an isothermal small circular cylinder in cross-flow in a rectangular ventilation duct.

▸ A passive technique for enhancement of heat transfer from a cylinder is examined. ▸ The boundary layer was perturbed locally through a static device. ▸ The results shown an improvement of the order of 50%.