Review on Heat Transfer Enhancement by Louvered Fin

Samsul Islam,Md Shariful Islam,Mohammad Zoynal Abedin

doi:10.26776/ijemm.06.01.2021.06

Samsul Islam, Md Shariful Islam + Show 1 more

Open Access

https://doi.org/10.26776/ijemm.06.01.2021.06

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Abstract

The heat transfer enhancement is recycled in many engineering uses such as heat exchangers, refrigeration and air conditioning structures, chemical apparatuses, and automobile radiators. Hence many enhancing extended fin patterns are developed and used. In multi louvered fin, in this segment for multi-row fin and tube heat exchanger, an increase in heat transfer enhancement is found 58% for ReH = 350. When the Reynolds number is 1075, the temperature gradient is more distinct for greater louver angle that is the higher heat transfer enhanced for large louver angle. For variable louver angle heat exchanger, the maximum heat transfer improvement achieved by 118% Reynolds number at 1075. In the vortex generator for the delta winglet vortex generator, the extreme enhancement of heat transfer increased to 16% compared to the baseline geometry (at ReDh = 600). For a compact louvered heat exchanger, the results showed that a regular arrangement of louvered fins gives a 9.3% heat transfer improvement. In multi-region louver fins and flat tubes heat exchanger, the louver fin with 4 regions and the louver fin with 6 regions are far better than the conventional fin in overall performance. At the same time, the louver fin with 6 regions is also better than the louver fin with 4-region. The available work is in experimental form as well as numerical form performed by computational fluid dynamics.

Highlights

Nowadays, Researchers are concentrating on the improvement of the performance of heat exchangers having a high degree of surface compactness and optimal overall thermal-hydraulic performance
Rugh et al, [13] calculated heat transfer coefficients and friction losses for high-density louvered fin and flat tube heat exchangers (2000 fins/m) and suggested j and f correlations. It has been found from their study that a louvered fin heat exchanger formed a 25% increase in heat transfer and a 110% increase in pressure drop comparative to a plain fin
8 SUMMARY It has shown from Figure 24 the greatest heat transfer enhancement is achieved approximately 118%for the louver fin heat exchangers with variable louver angle compared with general devices

Summary

INTRODUCTION

Davenport [7, 8], Achaichia [9], Achaichia and Cowell [10] observed air-side heat transfer and flow performance for louvered fin heat exchangers and obtained j and f factors as occupations of the Reynolds number. Huihua and Xuesheng [11] accompanied an investigational study by a scaled-up louvered fin model with dissimilar louver angles and pitches Their investigational results showed that both the strength of heat transfer and pressure drop improved with growths in oblique angle and plate length. 8 SUMMARY It has shown from Figure 24 the greatest heat transfer enhancement is achieved approximately 118%for the louver fin heat exchangers with variable louver angle compared with general devices. The average value of heat transfer enhancement we studied about 58% for the multi-row fin and tube heat exchanger compared with regular devices. The minimum value of heat transfer enhancement is 9.3% for the compact louvered heat exchanger compared with general devices

Working fluid

Air and water

Inclined louvered fins

Findings

CONCLUSIONS