Comparative study on single-phase flow and heat transfer of different cross-section rib-soft tail structures

Enhanced heat transfer technique using vortex-induced vibration is an effective way to realize the cooling of heat exchange equipment. In this paper, based on the arbitrary Lagrange-Euler (ALE) algorithm, the two-way fluid-structure-interaction and heat transfer problem in the channel of rib-soft tail structure with different Reynolds numbers, different cross-sectional shapes, and different length-to-diameter ratios is investigated by using numerical simulations with dynamic mesh and overset mesh technique, and the main research objects are the flow and heat transfer characteristics around the rib-soft tail structure, the heat transfer characteristics of the ribbed heated wall, and the integrated flow and heat transfer capacity of the whole channel. The simulation working conditions are: Reynolds number Re = 200, 275, 351; rib cross-sectional shapes: circular and square; length-to-diameter ratio k = 2, 3, 4. The results show that, at Reynolds number Re = 275, the flow-heat transfer capability of the rib-soft tail structure with circular cross-section is better than that of the structure with square cross-section, and the rib-soft tail structure with circular cross-section is optimal when the length-to-diameter ratio k = 3; and the local heat transfer capacity around the rib is better for square cross-section structure than for circular ones. With the increase of Reynolds number at the length-to-diameter ratio k = 3, the combined flow-heat transfer capacity of rib-soft tail structure with different cross-sections increases gradually. Moreover, the integrated flow heat transfer capacity of circular cross-section with high Reynolds number and high length-to-diameter ratio is the best. Comparing the flow-heat transfer capacity with a rib structure without soft tail, for the circular cross-section rib structure, the integrated heat transfer capacity increases by 19.46% after adding the soft tail structure, whereas for the square cross-section rib, the capacity decreases slightly after adding the soft-tail. This provides a theoretical basis for studying the cooling design of heat exchange equipment. © 2024 Materials China. All rights reserved.