3D-CFD simulation and neural network model for the j and f factors of the wavy fin-and-flat tube heat exchangers

Abstract

A three dimensional (3D) computational fluid dynamics (CFD) simulation and a neural network model are presented to estimate the behaviors of the Colburn factor (j) and the Fanning friction factor (f) for wavy fin - and - flat tube (WFFT) heat exchangers. Effects of the five geometrical factors of fin pitch, fin height, fin length, fin thickness, and wavy amplitude are investigated over a wide range of Reynolds number (600<Re<7000). The CFD simulation results express that the geometrical parameters of wavy fins have significant effects on the j and f factors as a function of Reynolds number. The computational results have an adequate accuracy when compared to experimental data. The accuracy of the calculations of the j and f factors are evaluated by the values of the absolute average relative deviation (AARD), being respectively 3.8% and 8.2% for the CFD simulation and 1.3% and 1% for the neural network model. Finally, new correlations are proposed to estimate the values of the j and f factors with 3.22% and 3.68% AARD respectively

Al 2 O 3 –water nanofluid inside wavy mini-channel with different cross-sections

“…According to our previous studies [31][32][33], enhancement of flow path and generation of swirl flows along/perpendicular to the flow direction are the remarkable phenomena in the wavy channels. It seems that the geometry of the cross-section can considerably affect the number, strength, and location of these swirl flows inside the WMC.…”

Investigation of thermal-hydraulic performance in flat tube heat exchangers at various tube inclination angles

“…Some researchers have studied the effects of some of the aforementioned parameters on the thermal-hydraulic performance of flat tube HE. Numerous numerical and experimental studies have been done to determine the air-side thermal and flow performances using different types of tubes and fins [10,[18][19][20][21][22]. Nascimento and Garcia [23] reported that flat tube with a shallow square dimple enhanced the heat transfer considerably.…”

A numerical study on the thermal hydraulic performance of finned elliptical tube with wet air flowing around

“…Wavy fin was another type of fin. Khoshvaght et al [9] established the mathematical model of the wavy fin-and-flat-tube heat exchanger to analyze the heat transfer and resistance performance. Of course, there were improvements around fins in recent years.…”