Triple Hotwire for Furthering Flat Surface Turbulent Heat Convection

Enhancing heat transfer can improve the performance of many systems. This is also the case with the promising solar photovoltaic (PV) system. The percentage energy conversion efficiency increases by approximately 0.65% per 1℃ drop in the cell temperature. Accordingly, a significant amount of effort has been invested into effectively removing heat from the panel to boost efficiency. Among other means, turbulence generators, one of the passive cooling techniques, have drawn great attention in recent years due to their simplicity, robustness, and potency. A novel turbulence generator, a rectangular flexible strip, was explored in the current study for its effectiveness in realizing forceful convective cooling of a heated flat surface.

To understand the physics behind the heat transfer augmentation, the strip-induced turbulent flow was detailed with the help of a hotwire system. As this turbulent flow was expected to be highly three dimensional and rich in different scales of eddying motions, a high-resolution flow measurement technique with three-dimensional sensing capability was called upon. Accordingly, a 3D hotwire probe (type 55P95) with a StreamLine Pro constant-temperature anemometer was selected.