Optimization of the angle of attack of delta-winglet vortex generators in a plate-fin-and-tube heat exchanger

Abstract Delta-winglet vortex generators (VGs) are known to enhance the heat transfer between the energy-carrying fluid and the heat transfer surfaces in plate-fin-and-tube banks. In this study optimal angles of attack of the delta-winglets are investigated based on the Pareto optimal strategy. The optimization process combines a CFD analysis, genetic algorithms and the response surface methodology. The angle of attack of a pair a delta-winglet-type VGs mounted behind each tube is varied between β  = −90° and +90°. Three circular tube rows with inline and staggered tube arrangements are investigated for Reynolds numbers from 200 to 1200 (based on the inlet height and inlet velocity). The flow structure and heat transfer behavior is analyzed in detail for certain cases and the staggered and the inline tube arrangements are compared. Finally, for each of these arrangements the optimal sets of angles of attack for different Reynolds numbers are presented.

[1]  Anthony M. Jacobi,et al.  Heat Transfer Enhancement by Delta-Wing-Generated Tip Vortices in Flat-Plate and Developing Channel Flows , 2002 .

[2]  David E. Goldberg,et al.  Genetic Algorithms in Search Optimization and Machine Learning , 1988 .

[3]  Peter J. Fleming,et al.  Genetic Algorithms for Multiobjective Optimization: FormulationDiscussion and Generalization , 1993, ICGA.

[4]  Timothy W. Simpson,et al.  Metamodels for Computer-based Engineering Design: Survey and recommendations , 2001, Engineering with Computers.

[5]  J. Friedman.  Multivariate adaptive regression splines , 1990 .

[6]  Gautam Biswas,et al.  Heat transfer enhancement in fin-tube heat exchangers by winglet type vortex generators , 1994 .

[7]  M. Fiebig,et al.  Comparison of Wing-Type Vortex Generators for Heat Transfer Enhancement in Channel Flows , 1994 .

[8]  George E. P. Box,et al.  Empirical Model‐Building and Response Surfaces , 1988 .

[9]  Urmila M. Diwekar,et al.  Optimal Design of Heat Exchangers: A Genetic Algorithm Framework , 1999 .

[10]  Carl E. Rasmussen,et al.  Gaussian processes for machine learning , 2005, Adaptive computation and machine learning.

[11]  P. Jain,et al.  Multiobjective placement of electronic components using evolutionary algorithms , 2004, IEEE Transactions on Components and Packaging Technologies.

[12]  A Review on Heat Transfer Enhancement by Longitudinal Vortices , 1997 .

[13]  A. Gosman,et al.  Solution of the implicitly discretised reacting flow equations by operator-splitting , 1986 .

[14]  Kalyanmoy Deb,et al.  Multi-objective optimization of a leg mechanism using genetic algorithms , 2005 .

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

[16]  Chi-Chuan Wang,et al.  Heat transfer and friction characteristics of plain fin-and-tube heat exchangers, part I: new experimental data , 2000 .

[17]  Murray Smith,et al.  Neural Networks for Statistical Modeling , 1993 .

[18]  Vinayak Eswaran,et al.  Heat transfer enhancement in cross-flow heat exchangers using oval tubes and multiple delta winglets , 2003 .

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

[20]  Giampietro Fabbri,et al.  Heat transfer optimization in corrugated wall channels , 2000 .

[21]  Kalyanmoy Deb,et al.  A fast and elitist multiobjective genetic algorithm: NSGA-II , 2002, IEEE Trans. Evol. Comput..

[22]  Douglas C. Montgomery,et al.  Response Surface Methodology: Process and Product Optimization Using Designed Experiments , 1995 .

[23]  F. Durst,et al.  Performance comparison of pin fin in-duct flow arrays with various pin cross-sections , 2006 .

[24]  Martin Fiebig,et al.  Heat transfer enhancement and drag by longitudinal vortex generators in channel flow , 1991 .

[25]  Koichi Nishino,et al.  Numerical and experimental determination of flow structure and heat transfer effects of longitudinal vortices in a channel flow , 1996 .

[26]  Anthony M. Jacobi,et al.  Air-side heat transfer enhancement of a refrigerator evaporator using vortex generation , 2005 .

[27]  S. Rippa,et al.  Numerical Procedures for Surface Fitting of Scattered Data by Radial Functions , 1986 .

[28]  Karen A. Thole,et al.  Heat transfer augmentation along the tube wall of a louvered fin heat exchanger using practical delta winglets , 2008 .

[29]  C. Fonseca,et al.  GENETIC ALGORITHMS FOR MULTI-OBJECTIVE OPTIMIZATION: FORMULATION, DISCUSSION, AND GENERALIZATION , 1993 .

[30]  Anthony M. Jacobi,et al.  Impact of leading edge delta-wing vortex generators on the thermal performance of a flat tube, louvered-fin compact heat exchanger , 2005 .