Employing the Concept of Fractal Shape to Enhance Heat Transfer
Author: Khaled S M KH. Almutairi
Publisher:
Published: 2017
Total Pages:
ISBN-13:
DOWNLOAD EBOOKAn experimental study of the effect of the fractal square grid (FSG) iteration number (N) parameter on heat transfer is carried out. Using four different FSGs with four different N, the experiment is done using a closed system water tunnel. Particle Image Velocimetry (PIV) is used to characterize the turbulence of the flow downstream of the grids. Heat transfer measurements are performed around a circular cylinder centerline circumference without the grids first for Reynolds number range of 8473 = Re = 27192. After, measurements of heat transfer are done around the cylinder downstream each grid for four different stream-wise distances from the cylinder with Reynolds number of 8473 that is based on the cylinder diameter (d).Turbulence intensities (Tu) of all grids show relatively different trends with higher Tu for grids with higher N. Heat transfer results under laminar free-stream condition show a good agreement with the predicted empirical correlations in literature. Heat transfer measurements are performed downstream of two grids only, which are FSG4 and SSG. Results indicated that FSG4 introduces higher heat transfer enhancement in general than SSG. While, SSG outperforms FSG4 in heat transfer enhancement for relatively close distances from the cylinder.