Effect of vortex generators in accelerating the thermal diffusion

• Main Authors: Saood, Marwa M., Jalil, Saad M.
• Format: Conference Proceeding
• Language: English
• Subjects: Angle of attack; Circular tubes; Coefficient of friction; Fluid flow; Heat transfer; Leading edges; Reynolds number; Rotation; Thermal diffusion; Vortex generators; Vortices; Working fluids
• ISSN: 0094-243X; 1551-7616
• DOI: 10.1063/5.0190513

In this article, an experimental study was conducted to verify the effect of delta winglet vortex generators (DWVG) inside a circular tube. Water is the working fluid used in this study, with a Reynolds number range of 2500-12500. The vortex generators are arranged inside the tube in a series of four rings, each ring comprising three pairs of DWVG on the inner surface of the circular tube. Single ring spacing (pitch=200 mm), wing height H=10 mm, DWVG wing angle of attack α=40°, distance between leading edges of one pair of (DWVG) S=8 mm. The current study aims to determine the effect of the angle of rotation of the bearing rings of the vortex generators on improving heat transfer. The DWVG-bearing rings inside the tube were rotated at different angles(φr) (0°, 20°, 40°). The results showed that the Nusselt number increased with the increase of the Reynolds number and the coefficient of friction decreased with the increase in the Reynolds number. The presence of vortex generators led to an improvement in heat transfer. The highest Nu level was obtained when rotating the rings bearing the vortex generators at an angle of (φr)= 20°) Re=12500. Also, the highest PEC=1.6 at Re=2500 with a rotation angle of the rings by 20°.