A Comparative Study of Channel Cooling Enhancement by Angled, Parallel Broken, and Rhombus Patterned Ribs

Abstract

Heating and cooling of fluids play an important role in energy engineering, such as solar air heaters and the internal cooling of gas turbine blades. Heat transfer in the heat exchanger channels can be enhanced by ribs, which will also result in a significant decrease in coolant pressure. In our previous work, a novel bioinspired rib design with a rhombus-shaped pattern was proposed to enhance the channel cooling. The Nusselt numbers and flow characteristics are further compared to angled and parallel broken ribs in this work. It is interesting to find that the proposed channel with decreasing-height rhombus-shaped patterned ribs exhibits the best heat transfer performance. At the same time, the Nusselt number and friction factor are related to the Reynolds number in the studied range. The surface with rhombus-shaped patterned ribs shows greater thermal performance factors than that with angled ribs, while the surface with a decreasing-height rib arrangement has the highest thermal performance factor due to a better Coanda effect. This work confirms that the proposed ribs with decreasing height rhombus-shaped patterns are effective for enhancing the internal cooling of the channel.