Convective heat transfer and fluid flow characteristics in fin and oval-tube heat exchanger

Abstract

The forced convective heat transfer behavior of a turbulent air flow, steady and Newtonian over a fin and oval-tube heat exchanger has been examined numerically. Where, the effect of the tube tilt angle (α) on the heat transfer coefficient and the friction factor was tested. The inclination angle of the oval-tubes going from 0° (Baseline case) to 90° with a step of 10°. The fluid flows and heat transfer characteristics are presented for Reynolds numbers ranging from 3.000 to 12.000. All investigations are carried out with the help of the CFD ANSYS Fluent. Heat transfer coefficient results in the term of the Nusselt number are validated with the available experimental data and a maximum deviation of 9 % is observed. Reasonable agreement is found. The obtained results show that the tube's inclination angle of 20° is the best design which significantly removes the hot spots behind the tubes, thus giving an increase in the heat transfer coefficient of 13 % compared to the baseline case. In addition, useful correlations are developed to predict Nusselt number and friction factor in the fin and oval-tube heat exchanger.

The effect of triangular shutter type flow deflector perforated baffle plate on the thermofluid performance of a heat exchanger

“…The results indicated a max TEF of 1.77 obtained with inline arrangement at PR of 2.5 and Re of 3000. Abdoune et al 33 numerically analyzed the turbulent thermofluid behaviour of airflow in a fin and oval‐tube HX. The impact of the tube's tilt angle ( α ) varying from 0° to 90° in increments of 10° on the HT coefficient and f was studied with Re ranging from 3000 to 12,000.…”

Numerical Investigation for Single-Phase and Two-Phase Flow in Duct Banks with Multi Types of Vortex Generators

“…In recent years, researchers have investigated several additional areas for vortex generator forced convection enhancement, including the addition of bulges, dimples, and punched delta winglets as vortex generators are all geometric features. The collected data indicate that a tube incidence angle of 20° is the optimal structure for eliminating the hot areas among the tubes and increasing the heat convection coefficient by 13% according to the base scenario (Abdoune et al, 2021). It is known that tube diameter and height variances impact the convection heat coefficient value (Susmiati et al, 2022).…”