Effect of Longitudinal-External-Fins on Fluid Flow Characteristics for Wing-Shaped Tubes Bundle in Crossflow

Abstract

A numerical study is conducted to clarify fluid-flow characteristics, pressure drop coefficient (Pdc), and the average skin friction coefficient (Cf,m) for wing-shaped-tubes bundle with longitudinal fins at downstream side of the tube using the commercial CFD FLUENT software package. The air-side Rea ranges from 1800 to 9700. The tubes are employed with various fin heights (hf) and fin thicknesses (δ) such as 2 mm ≤ hf ≤ 12 mm and 1.5 mm ≤ δ ≤ 3.5 mm at the considered Rea range. Results indicate that ΔPa increases with Rea for all hf. Pdc decreases with Rea for all hf values for 1800 ≤ Rea ≤ 4200 and then increases for 4200 ≤ Rea ≤ 10000. Lowest values of ΔPa, Pdc, and pumping power (PP) occurred at hf = 6 mm. Values of Pdc for hf = 6 mm are lower than those of NOF and hf = 2 mm by about 73 % and 32 %, respectively, at Rea = 4000. Cf,m decreases with Rea. δ has negligible effect on Cf,m. ΔPa increases for 1.5 mm ≤ δ ≤ 2.5 mm while ΔPa decreases with 2.5 mm < δ ≤ 3.5 mm for the considered Rea range except for Rea = 1850.

Second law optimization of heat exchangers in waste heat recovery

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Energy and Exergy Analyses of Tube Banks in Waste Heat Recovery Applications

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“…Once the geometry is created and meshed appropriately, ANSYS Fluent 18.2 is used to solve the problem in question. Each simulation is run in a transient fashion, and the k-RNG turbulence model is utilized, as is customary in similar studies [22][23][24][25], due to more reliable results for cross-flow problems, including swirl, separation and recirculation of the fluid. The pressure-corrector, the SIMPLEC (Semi-Implicit Method for Pressure Linked Equations-Consistent) algorithm, is used, with a convergence criterion of 1 × 10 −6 for the continuity, momentum and energy equations.…”

“…Thermodynamics analyses were investigated using Equations (6)- (22). The primary purpose here was to investigate how energy and exergy efficiencies change with respect to the Reynolds number, pitch ratio and number of tubes.…”

Experimental and CFD prediction of heat transfer and friction factor characteristics in cross flow tube bank with integral splitter plate

“…In addition, to the above mathematical basis, number of researchers [19,30,31] prefer RNG k-e model in case of flow across tube bank and reports better compatibility with the experimental data.…”