Heat Transfer Characteristics of Grooved Fin Under Forced Convection

Abstract

Material removal from an extended surface in the form of perforations and slots is a proven technique to augment heat transfer rates with a considerable reduction in the surface weight. This work presents the outcomes of experimental investigation on heat transfer characteristics of a plate fin having grooves of various configurations on two broad faces. The experimental data pertaining to heat transfer have been collected by varying Reynolds number from 1500 to 5000, for transverse grooved, inclined grooved, V-grooved, and multi-V-grooved fin. The results of the grooved fin are compared with that of a smooth conventional fin to gauge the heat transfer performance of modified fin. The maximum enhancement in Nusselt number corresponds to the inclined groove fin, whereas the highest value of grooved fin effectiveness is obtained for the multi-V-grooved fin. The Nusselt number correlations are presented for different fin configurations tested in this work.

NOMENCLATURE

Ao	=	cross-section area of the orifice (m2)
At	=	total heated surface area including the base plate (m2)
Cd	=	coefficient of discharge of orifice
Cp	=	specific heat of air at constant pressure at mean air temperature (J/kg-K)
Dh	=	equivalent hydraulic diameter of duct (m)
g	=	gravitational acceleration (m/s2)
h	=	convective heat transfer coefficient (W/m2-K)
H	=	height of duct (m)
k	=	thermal conductivity of air at mean air temperature (W/m-K)
L	=	length of test section of duct (m)
	=	mass flow rate of air (kg/s)
Nu	=	Nusselt number of grooved fin geometry
Nus	=	Nusselt number of solid fin
Pa	=	ambient pressure (N/m2)
Pr	=	Prandtl number
Q	=	heat transfer rate (W)
Qg	=	heat transfer rate from a grooved fin (W)
Qs	=	heat transfer rate from a solid fin (W)
R	=	gas constant for air (J/kg-K)
Re	=	Reynolds number
t	=	thickness of fin (m)
Tam	=	mean air temperature (K)
Tfm	=	mean fluid temperature (K)
Ti	=	inlet air temperature (K)
To	=	average outlet air temperature (K)
Tpm	=	mean plate temperature (K)
Ts	=	mean surface temperature (K)
v	=	mean velocity of air (m/s)
W	=	width of duct (m)

Greek Symbols

β	=	ratio of orifice diameter to pipe diameter
(Δp)o	=	pressure drop across orifice plate (N/m2)
μ	=	dynamic viscosity of air at mean air temperature (N-s/m2)
ρ	=	density of air at mean air temperature (kg/m3)
ρo	=	density of air corresponding to outlet air temperature (kg/m3)
ρm	=	density of manometric fluid (kg/m3)
ϵg	=	grooved fin effectiveness

Additional information

Notes on contributors

Ashish Dixit

Ashish Dixit is an assistant professor in the Mechanical Engineering Department at Dehradun Institute of Technology, Dehradun, India. He has completed his graduation in mechanical engineering from UP Technical University, Lucknow, India, and postgraduation in thermal engineering from Uttarakhand Technical University, Dehradun, India. He has more than 7 years of experience at academic institutions and industries. He is currently working on experimental investigation of heat transfer enhancements from extended surfaces.

Anil Kumar Patil

Anil Kumar Patil is an associate professor in the Mechanical Engineering Department at Dehradun Institute of Technology, Dehradun, India. He received his Ph.D. degree from Uttarakhand Technical University, Dehradun, India, in the area of heat transfer. He has completed his graduation from Barkatullah University, Bhopal, India, and postgraduation in thermal engineering from M.A.N.I.T., Bhopal, India. He has more than 13 years experience of teaching at the undergraduate and postgraduate level and published more than 10 research papers in international/national journals and in the proceedings of the international/national conferences. His research interests include heat transfer enhancement techniques and solar energy utilization.