Research on heat transfer enhancement and flow characteristic of heat exchange surface in cosine style runner

The steady state heat transfer and flow resistance performance in cosine style runners with different amplitudes are studied numerically and experimentally in this paper. The results show that: When the Reynolds numbers (Re) range from 1210 to 5080, the core volume goodness factor (eta(o)h(std)alpha) is used to compare the overall heat transfer performance of the two runners, and the eta(o)h(std)alpha value in the cosine style runner is 7-25% larger than that of the equal cross section runner, so that the cosine style runner has better overall heat transfer enhancement performance. When the amplitudes (2A) range from 5 to 9 mm, with the decrease of amplitude, the overall heat transfer performance is getting better. At the same amplitude, the convective heat transfer performance gradually increases as the inlet height (F-h) decreases; with the increase of Re, the thickness of the thermal and velocity boundary layers are both decreasing. Based on the field synergy principle, the heat transfer enhancement mechanisms with different parameters are evaluated, and we conclude that the smaller the amplitude is, its field synergy is better.