Heat transfer characteristics of a circular tube bank fin heat exchanger with fins punched curve rectangular vortex generators in the wake regions of the tubes

Vortex generators (VGs) applied on the fin surfaces of circular tube bank fin heat exchangers can increase the intensity of secondary flow and reduce the size of wake regions behind circular tubes. In this study, a new type of the fin is reported, on which curve rectangular vortex generators (CRVGs) are punched. A numerical method is used to investigate the fluid flow and heat transfer characteristics of the fin. The average Nusselt number, friction factor and secondary flow intensity are larger than that of the reference plain fin at different Re, respectively. The local Nusselt number on the fin surface contacting with the wake region increases significantly. The circumferential position, the radial position, the base arc length and height of VGs and the fin spacing are the main parameters investigated to disclose their effect on the heat transfer performance of the fin. When the leading edge of VGs is located in the transversal axis of the tube, the diameter of the base arc length of VGs is large, the height of VGs is about 0.8 times of the fin spacing, heat transfer performance is optimal, and the base arc length of VGs is about 3.8 times of the optimal height of VGs, better heat transfer performance can be obtained. For working condition of different Reynolds number, when the ratio of the fin spacing to the tube outer diameter is 0.239, better heat transfer performance is obtained.

[1]  Dominique Della Valle,et al.  Enhancing heat transfer in vortex generator-type multifunctional heat exchangers , 2012 .

[2]  Pan Chu,et al.  Analysis of heat transfer and pressure drop for fin-and-tube heat exchangers with rectangular winglet-type vortex generators , 2013 .

[3]  Yong-Heng Zhang,et al.  Comparison of heat transfer performance of tube bank fin with mounted vortex generators to tube bank fin with punched vortex generators , 2008 .

[4]  L. B. Wang,et al.  The effects of span position of winglet vortex generator on local heat/mass transfer over a three-row flat tube bank fin , 2004 .

[5]  Qiuwang Wang,et al.  Optimization of heat exchangers with vortex-generator fin by Taguchi method , 2010 .

[6]  Gautam Biswas,et al.  Augmentation of Heat Transfer by Creation of Streamwise Longitudinal Vortices Using Vortex Generators , 2012 .

[7]  L. B. Wang,et al.  Local and Average Characteristics of Heat/Mass Transfer Over Flat Tube Bank Fin With Four Vortex Generators per Tube , 2002 .

[8]  Antonio Delgado,et al.  Optimization of the angle of attack of delta-winglet vortex generators in a plate-fin-and-tube heat exchanger , 2010 .

[9]  Anthony M. Jacobi,et al.  Heat transfer enhancement by delta-wing vortex generators on a flat plate: Vortex interactions with the boundary layer , 1997 .

[10]  M. Fiebig,et al.  Heat transfer enhancement of finned oval tubes with staggered punched longitudinal vortex generators , 2000 .

[11]  C. Rhie,et al.  Numerical Study of the Turbulent Flow Past an Airfoil with Trailing Edge Separation , 1983 .

[12]  Amin Barari,et al.  Numerical analysis on longitudinal location optimization of vortex generator in compact heat exchangers , 2011 .

[13]  Steven Beale,et al.  A Simple, Effective Viscosity Formulation for Turbulent Flow and Heat Transfer in Compact Heat Exchangers , 2012 .

[14]  Liang-Bi Wang,et al.  Numerical study of the relationship between heat transfer enhancement and absolute vorticity flux along main flow direction in a channel formed by a flat tube bank fin with vortex generators , 2009 .

[15]  Rui Li,et al.  Three-dimensional numerical study on fin-and-oval-tube heat exchanger with longitudinal vortex generators , 2009 .

[16]  R. Shah,et al.  Heat transfer surface enhancement through the use of longitudinal vortices: a review of recent progress , 1995 .

[17]  Ke-Wei Song,et al.  The criteria of convergence in conjugated simulation of fluid flow and heat transfer in the channel formed by tube bank fins , 2011 .

[18]  W. Tao,et al.  A New Stability-Guaranteed Second-Order Difference Scheme , 2002 .

[19]  Jiangbo Wu,et al.  Effect of longitudinal vortex generator on heat transfer in rectangular channels , 2012 .

[20]  Jiin-Yuh Jang,et al.  Heat transfer and fluid flow analysis in plate-fin and tube heat exchangers with a pair of block shape vortex generators , 2004 .

[21]  Liang-Bi Wang,et al.  Tube Transverse Pitch Effect on Heat/Mass Transfer Characteristics of Flat Tube Bank Fin Mounted With Vortex Generators , 2008 .

[22]  Vinayak Eswaran,et al.  Enhancement of Heat Transfer Using Delta-Winglet Type Vortex Generators with a Common-Flow-up Arrangement , 2012 .

[23]  Liang-Bi Wang,et al.  The Characteristic Temperature in the Definition of Heat Transfer Coefficient on the Fin Side Surface in Tube Bank Fin Heat Exchanger , 2011 .

[24]  Mohd Zamri Yusoff,et al.  An overview on heat transfer augmentation using vortex generators and nanofluids: Approaches and applications , 2012 .

[25]  Pan Chu,et al.  Hydrodynamics and heat transfer characteristics of a novel heat exchanger with delta-winglet vortex generators , 2010 .

[26]  Lili Feng,et al.  Experimental study on heat transfer enhancement of wavy finned flat tube with longitudinal vortex generators , 2013 .

[27]  Hua Zhang,et al.  Experimental study on the performance of a novel fin-tube air heat exchanger with punched longitudinal vortex generator , 2012 .

[28]  Koichi Nishino,et al.  Heat transfer enhancement accompanying pressure-loss reduction with winglet-type vortex generators for fin-tube heat exchangers. , 2002 .

[29]  Liang-Bi Wang,et al.  A Multi-Domain Coupled Numerical Method for a Flat Tube Bank Fin Heat Exchanger with Delta-Winglet Vortex Generators , 2014 .

[30]  L. B. Wang,et al.  The Optimum Height of Winglet Vortex Generators Mounted on Three-Row Flat Tube Bank Fin , 2003 .

[31]  Liang-Bi Wang,et al.  Characteristics of the Absolute Vorticity Flux along the Main Flow Direction on the Cross Section of the Channel Formed by Oval Tube Bank Fins , 2010 .

[32]  Jiin-Yuh Jang,et al.  Numerical and experimental studies of threedimensional plate-fin and tube heat exchangers , 1996 .

[33]  M. Fiebig.  Embedded vortices in internal flow: heat transfer and pressure loss enhancement , 1995 .

[34]  Jiin-Yuh Jang,et al.  Optimization of the span angle and location of vortex generators in a plate-fin and tube heat exchanger , 2013 .

[35]  Jean-Marc Foucaut,et al.  Optimization of winglet vortex generators combined with riblets for wall/fluid heat exchange enhancement , 2013 .

[36]  Liang-Bi Wang,et al.  Convective Heat Transfer and Absolute Vorticity Flux along Main Flow in a Channel Formed by Flat Tube Bank Fins with Vortex Generators Mounted on Both Fin Surfaces , 2009 .

[37]  M. Fiebig,et al.  Heat transfer enhancement of a finned oval tube with punched longitudinal vortex generators in-line , 1998 .

[38]  Qiang Zhang,et al.  The optimum fin spacing of circular tube bank fin heat exchanger with vortex generators , 2013 .

[39]  Liang-Bi Wang,et al.  A NEW METHOD TO SPECIFY THE OUTLET BOUNDARY CONDITION OF FLUID FLOW IN THE CHANNEL FORMED BY TUBE BANK FINS , 2011 .