Fin angle effect on turbulent heat transfer in parallel‐plate channel with flow‐inclining fins

Abstract

Purpose

This paper aims to develop enhanced surfaces that possess improved heat transfer rate with moderate flow pressure‐drop.

Design/methodology/approach

The characteristics of the heat transfer and flow resistance in a parallel‐plate channel with flow‐inclining fins have been numerically and experimentally studied. In the turbulent flow range, the effect of the fin angle from 0 to 23.2° in addition to three channel heights, has been investigated.

Findings

The friction factor and the Nusselt number of the experimented 3D finned ducts are both lower than those of the numerical 2D channel at the same Reynolds number. The assessment under the constraint of the same pump power consumption shows that the enhancement ratio, Nu_m/Nu₀, is in between 1.6 ∼ 3.3. Showing different priority, the fin of β=23.2° is the most profitable for the 2D channel, while the case of β=16.0° is superior to the other fin angles for thicker 3D ducts.

Research limitations/implications

For wide flat channels the 3D fins rather than the 2D fins are profitable. The deployment of the 3D fin, which is unchangeable in the current study, should be further optimized. The fin dimension and configuration in other duct forms are also challenging subjects.

Practical implications

The results can be referenced by those who engage in design of plate‐fin heat exchangers. Attention should be paid to the optimum fin angle for different aspect ratios of the duct.

Originality/value

The study provides a practical fulfillment of the effective enhancement of the convective heat transfer with properly designed inserts that the field synergy principle predicted.

Citation

Yuan, Z.X., Zhao, L.H. and Zhang, B.D. (2007), "Fin angle effect on turbulent heat transfer in parallel‐plate channel with flow‐inclining fins", International Journal of Numerical Methods for Heat & Fluid Flow, Vol. 17 No. 1, pp. 5-19. https://doi.org/10.1108/09615530710716054