Effect of Horizontal Spacing on Natural Convection Heat Transfer from Two Aligned Horizontal Cylinders in a Vented Enclosure

Abstract

Natural convection heat transfer from horizontally aligned two heated cylinders placed inside a square vented enclosure has been investigated numerically for laminar flow. The Navier-Stokes equations and energy equations have been employed to simulate the flow and thermal behaviors with a finite volume (SIMPLE) method to represent and evaluate the partial differential equations in the form of algebraic equations using ANSYS-FLUENT 16.1 Package. The study has employed a range of Rayleigh numbers from 10 3 to 10 7 with the variation of horizontal spacing between two cylinders and symmetrical open vent size with constant enclosure width. The results displayed that the average Nusselt number is increased with the increase of the Rayleigh number, spacing between cylinders, and opening size. The maximum enhancement range for average Nu is between 50 and 100% for low Ra and 20-30% for high Ra with full opening size and large spacing size. The variation of the local Nusselt numbers, streamlines, and isotherms displayed the effect of the Rayleigh number, opening size, and spacing between cylinders on the flow and thermal behaviors.

Impact of size and location of outflow opening vent on mixed convective heat transfer induced by two aligned heated cylinders immersed in a partially open channel

“…Mixed convective heat transfer can increase when the impact of forced and free convection is comparable, which it is not possible to neglect either process. On the basis of previous studies, mixed convection may occur when $${{Gr}}_{L}/R{e}_{L}^{2}\approx 1$$, whereas forced and natural convection can occur when $${{Gr}}_{L}/R{e}_{L}^{2}\ll 1$$ and $${{Gr}}_{L}/R{e}_{L}^{2}\gg 1$$, respectively 1–6 . Mixed convection induced from a single cylinder in a duct has been presented in several studies 17–37 .…”

“…The mixed convective heat transfer induced from one or more heated cylinder placed inside either closed enclosure or vented enclosure can be found in the separation process in chemical industries, grains and food processing, geothermal energy systems, biological systems, storage of granular materials, electronic parts, cooling of electronic, solar heating collectors, thermal storage systems, oil and gas production, and the cooling system of the nuclear reactors. 1 The natural convection induced from a single hot cylinder inside the duct using different methods is presented in several investigations. [2][3][4][5][6][7][8][9][10] Kahwaji and Samaha 2 provided a new method to improve the mechanism of convection from a horizontal cylinder.…”

“…On the basis of previous studies, mixed convection may occur when L L 2 ≫ , respectively. [1][2][3][4][5][6] Mixed convection induced from a single cylinder in a duct has been presented in several studies. Nasseri et al 17 studied the mixed convection in a square duct using a fan to create a ventilation jet.…”

Kaviteye Yerleştirilen Açılı Kare Silindirden Doğal Ve Zorlanmış Taşınım

“…Generally, using nanofluid as a working fluid increases the heat transfer rates; moreover, increasing the volume fraction of nanoparticles contributes to heat transfer. There are more works on hot bodies placed in a cavity [6][7][8][9][10][11][12]. Furthermore, researchers implied active and passive heat transfer enhancement techniques to upgrade convection in a vented cavity.…”

Natural convection coupled to surface radiation in an air‐filled square cavity containing two heat‐generating bodies

“…Pandey et al 9 provide an in‐depth analysis of the experimental and numerical investigation of natural convection in closed enclosures with/without internal heat sources. The blocks (electronic components) can be attached to cavity walls 10,11 or surrounded by the working fluid 12–18 . These works discuss the effects of some pertinent parameters, such as the Rayleigh number, the block aspect ratio, its position, and the number of internal bodies, under various thermal boundary conditions (isothermal, heat‐generating, or simple heat‐conducting bodies).…”