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The present work represents a 3-D numerical investigation of forced convection heat transfer over circular and oval tube banks with longitudinal vortex generators (LVGs) for flow through a fin-and-tube heat exchanger. The thermo-hydraulic performance parameters are studied numerically using computational fluid dynamics (CFD) tool. It is found that within the range of Reynolds number (500-850) studied, the degree of heat transfer enhancement is greatly influenced by the tube shape. Heat transfer increases by 13 % when the angle of attack is varied from 15° to 25°, with a corresponding pressure drop of 40 % and 62 % for the oval tubes and circular tubes, respectively. The effect of the aspect ratio of the oval tubes is observed to be very significant. Several other performance parameters of the oval and circular tube banks with vortex generators under the same operating conditions are compared with a focus on finding an optimal configuration. [ABSTRACT FROM AUTHOR]

There is a desire to improve the forced convection heat transfer for various innovative shaped pin fin heatsink designs. Hence, a numerical investigation is conducted to observe the effect of convection heat transfer for various shaped pin fin heatsinks by changing various parameters on fluid and solid domains. Different shapes of perforations and bulges are added to create more surface area and flow pattern change. Several pin fin configurations are proposed for the design to increase the performance. Navier-Stokes's equations and RANS (Reynolds Averaged Navier-Stokes) based k − ε turbulence model governs the study's modeling. The investigations are performed using the CFD program for Reynolds numbers (Re) ranging from 8547 to 21,367. The results reveal that elliptical shape pin fins play a crucial role in enhancing hydro-thermal performance factor (HTPF). The circular perforated elliptical pin fin provides a maximum HTPF of 1.72 as the Re changes from 8547 to 21,367. A performance improvement of 56% to 72% is found, which merits consideration in the pin fin heatsink design. Furthermore, the heat transfer performance for the elliptical-shaped circular perforation pin fin is examined using copper-diamond composite material. The Cu-diamond composite has a maximum HTPF of 1.75 at a Reynolds number of 21,367. [ABSTRACT FROM AUTHOR]

This study explores the comparison of plate fin heatsinks to address the escalating challenges and the growing demand for industrial cooling. Plate fin heatsinks may replace plane (baseline) heatsinks to improve heat transmission while retaining volume. The three novel shape designs: arrowhead fin, hexagonal fin, and concave fin are introduced which are missing in existing literature. The simulation is conducted for Reynolds number (Re) ranging from 13049 to 52195. Elliptical perforated arrowhead, hexagonal, and concave heatsinks have 16.06 %, 16.64 %, and 17.36 % lower volumes than solid arrowhead, hexagonal, and concave heatsinks. The Nusselt number improved by 65.47 %, 69.87 %, and 37.71 % respectively for elliptical perforated arrowhead fin, elliptical perforated hexagonal fin, and elliptical perforated concave fin compared to the rectangular plate fin at Re = 52915. The Nusselt number also enhanced by 23.22 %, 17.91 %, and 8.02 % for the solid arrowhead fin, solid hexagonal fin, and solid concave fin respectively compared to the baseline case at Re = 52195. The maximum HTPF is 1.23 and 1.72 for solid arrowhead plate fin and elliptical perforated hexagonal plate fin respectively. The result of this novel shaped heatsink is promising and can be used as a substitute of traditional plane fin for relevant industrial applications in future. • Three novel shaped plate fin incorporation in place of traditional rectangular fin. • Elliptical perforated arrowhead, hexagonal and concave heatsinks have 16.06%, 16.64%, and 17.36% less volume than baseline. • At Re =52195, the arrowhead, hexagonal, and concave fins had 34.28%, 44.07%, and 27.48% higher Nu than the baseline case. • The maximum HTPF for solid arrowhead and elliptical perforated hexagonal plate fins is 1.23 and 1.72 respectively. • Different novel shape implementation broadens the range of potential design space of future plate fin heat sink. [ABSTRACT FROM AUTHOR]

Metallic inserts have been receiving considerable interest in recent research as a means of enhancing passive thermal performance. Nevertheless, little research has been conducted on Y-shaped inserts with different perforations. The purpose of this study is to seek out optimum performance in terms of heat transfer employing hexagonal, trapezoidal, kite, and hybrid shapes with Perforation Indexes (PI) of 10%, 20%, and 30%. While conducting the analyses, air is utilized as the working fluid, using Reynolds numbers (Re) ranging from 3000 to 21000. The findings demonstrate that Nusselt number (Nu) values of up to 225 can be achieved at Re = 21000 for trapezoidal designs with a PI of 20%. In contrast, such case seems to have the lowest friction factor (f) of 0.07, yielding in the most optimized thermal performance. With PI = 10%, hexagonal perforations have the maximum f of 0.24, making it particularly prone to pressure drop. When compared to the smooth tube, Nu improved up to 6.15 times and f enhanced up to 5.03 times. The trapezoidal configuration with PI = 20% yielded the highest thermal performance factor, a TPF of 3.68, making it the best optimal case in terms of both thermal and hydraulic performance. [ABSTRACT FROM AUTHOR]