Effects of wave number and average radius on flow and heat transfer in a curve-wave channel

The demand for high cooling capacity heatsinks has been increasingly promoted due to the fast elevated heat generation of modern electronic devices. High-performance microscale heat exchangers are often accompanied by considerable pressure drop penalty that limits their applications. In order to avoid large pressure drop while maintaining high heat transfer rate, a macroscale curved channel was proposed with applying the periodical wave structure on the channel sidewalls. A three-dimensional conjugated numerical model was established, and the effects of wave number and average radius on the hydrothermal performance were investigated. It was found that the heat transfer performance in the smooth-curve channel is significantly improved due to the wavy sidewalls with a moderate pressure drop penalty. The heat transfer enhancement is more noticeable in the channels with more wave units and smaller average channel radius. Furthermore, it was noted that the periodical thermal entrance effect exists on the inner and the outer convective surfaces of curve-wave channels, which can be attributed to the variations of the secondary flow with the wave direction along the channels.