ENHANCEMENT OF NATURAL CONVECTION HEAT TRANSFER OF PIN FIN HAVING PERFORATED WITH INCLINATION ANGLE

Modern elektronik cihazlarda perfore kanatlar kullanılarak ısı transferini artırma konusunda yeni gelişmeler mevcuttur. Bu çalışmada, yeni bir perfore kanat tasarımı sunulmaktadır. Dörtgen kesitli perfore fin değişik eğim açıları için incelenmiştir. Değişken ısı transferi alanı Signum Fonksiyonu ile modellenmiş ve Degenerate Hypergeometric Denklemi (DHE) yöntemi kullanılarak karmaşık enerji diferansiyel denklemi kullanılmış ve Kumner Serisi ile çözülmüştür. Sonuçlar arasında % 0.3 farklılık gözlenmiştir. 105 ve 106 Rayleigh Sayıları için iki geometrik model kullanılmıştır. Eğim açısının maksimum değerine kadar sıcaklık farkı ve etkenlik değerlerinde artış görülmüştür. Isı transferi oranı ve etkenlik değerleri % 18 den % 50 ye kadar artmıştır

KANATTA EĞIM VE PERFORE ETKISI ILE DOĞAL TAŞINIM ISI TRANSFERININ ARTIRILMASI

The development of the perforated fin had proposed in many studies to enhance the heat transfer from electronic pieces in modern devices. This paper presents a new design by using inclined perforated for a pin fin. Perforated with rectangular section and different angles of inclination was considered. Signum Function is used for modeling the variable heat transfer area. Set of parameters to handle the conduction and convection area were calculated. Degenerate Hypergeometric Equation (DHE) was used for modeling the Complex energy differential equation and then solved by Kummer's series. In the validation process, the finite element technique was used. The big reliability of the presented model comes from the high agreement of the validation results about (0.3%), therefore, the mathematic model has big dependability to deal with the inclined perforated fin. Two geometric models and range of the Rayleigh number from Ra=1?105 to Ra=1?106 were considered. The results show the increase of the inclination towards the max angle leads to the enhancement of the temperature difference, heat transfer, and effectiveness with and without the change of other parameters. Improved of Heat transfer ratio and effectiveness are ranging from 18% to 50%

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Abdullah H. M. AlEssa, 2009. One-dimensional finite element heat transfer solution of a finwith triangular perforations of bases parallel and toweredits base,Arch Appl Mech [ 79: 741-751].
Andrei D. Polyanin and Valentin F. Zaitsev, 2003 .hand bookof Exact solution for ordinary differential equations ,2nded (USA). ByCHAPMAN & HALL/CRC , P.213-490.
Ashok Fule,A .MSalwe ,A Zahir Sheikh,and Nikhil Wasnik, 2014. convectiveheat transfer comparison between solid and perforated pin fin,internationaljournal of mechanical and robotics research,Vol. 3, No. 2, April.
Bayram Sahin,and Alparslan Demir, 2008a.Performance analysis of a heat exchanger having perforated square fins, Applied Thermal Engineering [28 (2008) 621-632].
Bayram Sahin,and Alparslan Demir, 2008b.Thermal performance analysis and optimum design parameters of heatexchanger having perforated pin fins ,Energy Conversionand Management [49(2008) 1684-1695].
Elshafei .E. A. M, 2010. NaturalConvection Heat Transfer from a Heat Sink with Hollow / Perforated-Circular Pin Fins, Energy [35 (2010) 2870e2877].
Hazewinkel. M,1995. Encyclopaedia of Mathematics:A-Integral --Coordinates, Springer scienceand business media, [p:105-110 and 797-800].
Incropera,Dewitt, Bergman and Lavine , 2006. Fundamentalof heat and mass transfer,John Wiley & Sons; 6th edition , [p:95-160 and 560-594].
John W. Harris and Horst Stocker , 1998. Hand bookof mathematics and computational science , springer (USA) [p:130-150].
Kirpikov.V.A and Leifman.I.I, 1972. calculation of the temperature profile of a perforated fin, instituted of chemical apparatus design, Moscow. Vol.23, No.2, pp.316-321, August.
Kumbhar D.G,Dr.N.K sane , and Chavan S.T. , 2009. Finite Element Analysis and Experimental Study of Convective Heat Transfer Augmentation from Horizontal Rectangular Fin by Triangular Perforations, internationalconference on advances in mechanical engineering , National Institute of Technology, Surat -395 007, Gujarat, India , InternationalConference on Advances in Mechanical Engineering, [August:376-380] .
Mohamed L. Elsayed ,and Osama Mesalhy ,2014.Studying the performance of solid/perforated pin-fin heat sinks using entropy generation minimization , Heat Mass Transfer,[10.1007/s00231-014-1451-9].
MonojBaruah,Anupam Dewan and P. Mahanta, 2011.Performanceof Elliptical Pin Fin Heat Exchangerwith Three Elliptical Perforations, CFD Letters Vol. 3(2) [S2180-1363(11)3265-X].
Raithby GD, andHollandsKGT,1998.Natural convection. In: Warren M. Rohsenow,James R Hartnett, YoungI. Cho, Handbookof heat transfer,MCGRAW-HILL 3rdedition, [p:4-1 to 4-80].
Rao, S.S.,2011. The Finite Element Method in Engineering, fifth edition. Elsevier (USA) [p:473-541].
Saurabh D. Bahadure , andGosavi.G.D, 2014. Enhancementof Natural Convection Heat Transfer from Perforated Fin, International Journal of Engineering research, Volume No.3, Issue No.9, pp : 531-535.
Swee-Boon Chin ,Ji-JinnFoo,and Yin-Ling La ,2013. Forced convective heat transfer enhancement with-perforated pin fins, Heat Mass Transfer 49:1447-1458.
Zan WU, Wei LI, Zhi-jianSUN , and Rong-huaHONG,2012. Modeling natural convection heat transfer from perforated plates, Journal of-Zhejiang University-SCIENCE A [13(5):353-360].