Tube heat exchanger with new star shaped fins

Abstract

Abstract. The article compares the tube heat exchanger with annular fins with innovative star shaped fins. For the analysis of the heat transfer and pressure drop, the computational fluid dynamics analysis with ANSYS Fluent software was applied. Through the tubes flow the hot water and heat the cold air flowing around the fins and tubes. The validation of selected turbulence models (k-ω SST and k-ε Realizable) was performed by annular fins comparing with the results in the literature. The results of the numerical analysis for star shaped fins for 2200 <Re< 12000 show an average of 15 % higher fins efficiency, 13 % higher Nu number on the air side with reduction of the exchange surfaces weight of 23.8 % compared to annular fins.

Heat Transfer Intensification in a Heat Exchanger by Means of Twisted Tapes in Rib and Sawtooth Forms

“…The empirical correlations for the Nusselt number, friction factor, and aerothermal performance index developed from experimental results of TTRSs for all sawtooth angles (α) are shown as follows. Nu = 0.049Re 0.762 Pr 0.4 (tan(α/90)) 0.098 (18) f = 11.178Re −0.492 (tan(α/90)) 0.075 (19) API = 4.392Re −0.136 (tan(α/90)) 0.073 (20) Comparisons between the experimental data and the predictions are illustrated in Figure 8a-c. These figures show that the predictions are adequately accurate.…”

“…The desired augmented heat transfer rate is counterbalanced by an undesirably increased pressure drop [8][9][10][11][12][13]. In addition, turbulators are also presented in the forms of extended surfaces, for example, louvered and wavy fins [14,15], serrated fins [16,17], star-shaped fins [18], and perforated fins [19,20].…”

A numerical study for solid and serrated annular finned tube bundles

“…) model and Shear Stress Transport ( ) models are turbulence models frequently used in this kind of computational studies [2,14,17,29]. In this study, both turbulence models were tested and the turbulence model which gave the closest results with the literature was used.…”

“…7(a), two different turbulence models were compared with three different studies in the literature, and a validation study was carried out in terms of pressure drop. and turbulence models are widely used models for flow over cross-flow tube bundles numerical studies [14,17]. In Fig.…”

“…The effects of these parameters on heat transfer and pressure drop were examined and some correlations were obtained. Bošnjakovic et al [16,17] designed a new star-shaped fin geometry for a heat exchanger. As a result of experimental studies, this star-shaped fin gave 39.3 % better high results in terms of heat flux compared to normal circular fins.…”