TY - JOUR
T1 - Effects of surface roughness on forced convection and friction in triangular ducts
AU - Rang, H. J.
AU - Wong, T. T.
AU - Leung, C. W.
N1 - Funding Information:
Received 7 November 1997; accepted 6 March 1998. The authors wish to thank The Hong Kong Polytechnic University for the financial support of this project. Address correspondence to Dr. C. W. Leung, Associate Professor, Department of Mechanical Engineering, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong. E-mail: mmcwl@polyu.edu.hk
PY - 1998
Y1 - 1998
N2 - Experimental investigations had been conducted to study the forced convective heat transfer and pressure drop characteristics of the hydrodynamic fully developed turbulent flow in horizontal equilateral triangular ducts fabricated with Ike same length and hydraulic diameter but different surface roughness of 1.2, 3.0, and 11.5 μm. The experiments were performed with hydraulic diameter-based Reynolds number ranging from 7, 000 to 20, 000. The entire inner wall of the duct was heated uniformly, while the outer surface was thermally insulated. It was found that the variation of Stanton number (St) with friction factor (f) can be expressed by a relationship of St = C * f, where the constant (C) increases from 0.41 to 0.50 when the surface roughness is increased from 1, 2 to 11.5 μm. It was also concluded that the duct with a higher surface roughness will have better heat transfer performance. Nondimensional expressions for the determination of the heat transfer coefficient and friction factor of the equilateral triangular ducts with different surface roughness were also developed.
AB - Experimental investigations had been conducted to study the forced convective heat transfer and pressure drop characteristics of the hydrodynamic fully developed turbulent flow in horizontal equilateral triangular ducts fabricated with Ike same length and hydraulic diameter but different surface roughness of 1.2, 3.0, and 11.5 μm. The experiments were performed with hydraulic diameter-based Reynolds number ranging from 7, 000 to 20, 000. The entire inner wall of the duct was heated uniformly, while the outer surface was thermally insulated. It was found that the variation of Stanton number (St) with friction factor (f) can be expressed by a relationship of St = C * f, where the constant (C) increases from 0.41 to 0.50 when the surface roughness is increased from 1, 2 to 11.5 μm. It was also concluded that the duct with a higher surface roughness will have better heat transfer performance. Nondimensional expressions for the determination of the heat transfer coefficient and friction factor of the equilateral triangular ducts with different surface roughness were also developed.
UR - http://www.scopus.com/inward/record.url?scp=0032118478&partnerID=8YFLogxK
U2 - 10.1080/08916159808946564
DO - 10.1080/08916159808946564
M3 - Article
AN - SCOPUS:0032118478
SN - 0891-6152
VL - 11
SP - 241
EP - 253
JO - Experimental Heat Transfer
JF - Experimental Heat Transfer
IS - 3
ER -