Nomenclature

However, the correlations of Stanton number, Colburn j-factor and friction factor are defined for a large range of Reynolds number and geometric descriptions for heat exchangers with multi-louvered fins, it is necessary that the performance of every new type of heat exchanger is analysed individually due to the complexity of the combined effects of geometrical and oper-

In this chapter, the structure of the louvered fin is examined in terms of thermal and hydraulic performance by following the studies in the literature. Several experimental and numerical studies are analysed by the authors to present a guide for the louvered fin. It is clear that the geometric parameters such as fin pitch, fin height, louver pitch, louver angle, and flow depth have remarkable effect on the performance of a louvered fin heat exchanger. It can be stated that the combined effects of these parameters must be examined individually to design a high efficiency heat exchanger. The key points of this chapter for the researchers can be summarized

• Frontal air velocity and the louver angle are the determinative parameters for the flow regime over the louvered fins. The duct directed or louver directed flow can be formed by

• 2D numerical models are inadequate to predict the heat transfer coefficient due to the lack of the un-finned areas. 3D numerical is sensible to predict both heat transfer coefficient and

ing Reynolds number but they do not have a monotonic relation with the geometric

• However, the wide range of correlated data is available in the literature, every heat exchanger must be analysed individually due to combined effects of geometric parameters

This research was performed under the Santez Project (00865-STZ.2011–1). The authors would like to thank the Ministry of Science, Industry and Technology and the Research and Development Department of the Arçelik A.Ş. Eskişehir Refrigerator Plant for their

1/3) decrease with increas-

• The flow efficiency over the louvered fins is increasing with the louver directed flow.

ational parameters [33].

as follows:

friction factor.

6. Concluding remarks

86 Heat Exchangers– Advanced Features and Applications

the effects of these parameters.

and operating conditions.

Acknowledgements

support.

• Colburn j-factor increases with decreasing fin pitch. • Friction factor (f) decreases with increasing fin pitch.

parameters such as fin pitch and louver angle.

• The area goodness factor (j/f) and the volume goodness factor (j/f


h Heat transfer coefficient, W/(m<sup>2</sup> °C)


related with hc, Ac,f, Pf and kf, m−<sup>1</sup>

m\_ <sup>c</sup> Mass flow rate of the cold fluid, kg/s

