Impact of grooved cylinder on heat transfer by natural convection in cylindrical geometry

Abstract

The current study reports a numerical analysis of a two-dimensional steady-state natural convection heat transfer from grooved heated cylinder for laminar flow regime. Two groove shapes are investigated in this work: circular and triangular groove. Simulations were carried out by varying the groove location, radius ratio f from 0.1 to 1, and the Rayleigh number over the range [103–106]. The thermal and dynamic behaviors are carefully analyzed and compared to the case of non-grooved cylinder (model 0). It is found that the heat transfer rate rises up with the increase of Rayleigh number. In addition, the groove locations φ = −90, and 80° provide the lowest heat transfer rate. A decrease of 9.4% in the heat transfer rate is detected for the case of triangular groove with f = 0.7 and Ra = 105. On the other hand, the highest heat transfer rate is provided at a position φ = −45° and 45° for f > 0.65. For these last groove locations, lower f present optimal configurations to accumulate heat on the cylinder. In fact, circular grooved cylinder with f = 0.1 decreases the heat loss by 9.3% and 12.4% for the locations φ = −45° and 45°, respectively compared to model 0. These results would be useful for engineering applications that are interested in the accumulation or transfer of heat through cylindrical ducts.

Energy Efficiency Analysis of Natural Convection Heat Transfer in Concentric Annulus with Interior and Exterior Grooves

“…In this context, and as a continuation to our previous work, [25], we propose in this paper to study the heat transfer by natural convection in a grooved concentric annular space. The inner cylinder is kept hot while the outer one is cold.…”

“…This has been the subject of recent research works. They have focused on the study of natural convection in an annulus whose interior cylinder is elliptical, [19], rectangular, [20], triangular, [21], or even grooved cylindrical, [22], [23], [24], [25], since in many fluid transport applications, the flow must pass through grooved cylindrical pipes. Several research works have been developed in this dynamic to study the effect of the groove on the flow pattern, [22], studied using the particle image velocimetry (PIV) method the case of flow around cylinders containing rectangular grooves.…”

“…[24], compared flows around different groove shapes on cylinders: They determined through their experimental work the highest and lowest drag coefficient for the studied grooves. In our previous work, [25], we studied the convective transfer around a hot grooved cylinder in a cold rectangular cavity. We then developed a comparison between two shapes of groove: triangular and circular grooves.…”