Convective heat transfer enhancement downstream of a flexible strip normal to the freestream
International Journal of Thermal Sciences
Flexible strip, Heat transfer enhancement, Turbulence, Vortex shedding
Employing an appropriate turbulence generator is a simple and effective means to boost convective heat transfer. In this study, a flexible 12.7 mm wide by 38.1 mm tall rectangular strip positioned normal to the freestream is explored for its effectiveness in enhancing the convective cooling of a heated plate in a wind tunnel. The effect of the flexibility of the strip is of particular interest. Thus, strip thicknesses of 0.1, 0.2 and 0.25 mm are investigated at a wind velocity of 10 m/s, a Reynolds number based on the strip width and freestream velocity of 8.5 × 103. The resulting Nusselt number augmentation with respect to the unperturbed reference case is explained in terms of the turbulent flow characteristics detailed via a triple-sensor hotwire. A higher velocity toward the heated plate is detected behind the 0.1 mm-thick strip, contributing to the most effective heat transfer performance, approximately 0.1 higher than that associated with the 0.25 mm-thick strip in terms of the normalized Nusselt number.
Yang, Yang; Ting, David S.K.; and Ray, Steve. (2019). Convective heat transfer enhancement downstream of a flexible strip normal to the freestream. International Journal of Thermal Sciences, 145.