A numerical investigation of entropy generation in the entrance region of curved pipes at constant w

In this study, developing incompressible viscous flow and heat transfer in the curved pipes are studied numerically to analyze the entropy generation and thermodynamic optimization in the entrance region at a constant wall temperature. The governing equations including continuity, momentum and energy equations are solved using a second order finite difference method based on the projection algorithm. Entropy generation and optimal Reynolds number calculation based on the entropy generation minimization are carried out for two cases considering the two groups of non-dimensional parameters both numerically and analytically. The comparison of the numerical results in the entrance region with the analytical ones in the fully developed region indicates that both solutions predict nearly the same optimal Reynolds numbers, specially, for the first group of the non-dimensional parameters.

[1]  Lan Xiao,et al.  Exergy transfer characteristics of forced convective heat transfer through a duct with constant wall temperature , 2007 .

[2]  Cheng-Xian Lin,et al.  Laminar forced convection in the entrance region of helical pipes , 1997 .

[3]  Ahmet Tandiroglu,et al.  Effect of flow geometry parameters on transient entropy generation for turbulent flow in circular tube with baffle inserts , 2007 .

[4]  T. H. Ko,et al.  Thermodynamic analysis of optimal mass flow rate for fully developed laminar forced convection in a helical coiled tube based on minimal entropy generation principle , 2006 .

[5]  R. Friedrich,et al.  Navier–Stokes solutions of laminar flows based on orthogonal helical co-ordinates , 1999 .

[6]  Jinsuo Zhang,et al.  Fluid flow in a rotating curved rectangular duct , 2001 .

[7]  A. K. Satapathy,et al.  Thermodynamic optimization of a coiled tube heat exchanger under constant wall heat flux condition , 2009 .

[8]  A. Khaliq.  Thermodynamic optimization of laminar viscous flow under convective heat-transfer through an isothermal walled duct , 2004 .

[9]  L. Talbot,et al.  Flow in Curved Pipes , 1983 .

[10]  T. H. Ko,et al.  Thermodynamic analysis of optimal curvature ratio for fully developed laminar forced convection in a helical coiled tube with uniform heat flux , 2006 .

[11]  P. Hatzikonstantinou,et al.  A NUMERICAL PROCEDURE FOR THE LAMINAR HEAT TRANSFER IN CURVED SQUARE DUCTS , 2005 .

[12]  A. Bejan.  Entropy generation minimization: The new thermodynamics of finite-size devices and finite-time processes , 1996 .

[13]  T. H. Ko.  Numerical investigation on laminar forced convection and entropy generation in a curved rectangular duct with longitudinal ribs mounted on heated wall , 2006 .

[14]  T. H. Ko,et al.  Numerical Investigation of Laminar Forced Convection and Entropy Generation in a Helical Coil with Constant Wall Heat Flux , 2006 .

[15]  G. Karahalios,et al.  Mixed convection flow in a heated curved pipe with core , 1990 .

[16]  Kuen Ting,et al.  Entropy generation and thermodynamic optimization of fully developed laminar convection in a helical coil , 2005 .

[17]  J. Masliyah,et al.  Developing convective heat transfer in helical pipes with finite pitch , 1994 .

[18]  Kyoji Yamamoto,et al.  Flow through a rotating helical pipe with circular cross-section , 2000 .

[19]  Ramon Molina Valle,et al.  Numerical hydrodynamic and thermal analysis of laminar flow in curved elliptic and rectangular ducts , 1999 .

[20]  M.R.H. Nobari,et al.  A numerical analysis of developing flow and heat transfer in a curved annular pipe , 2009 .

[21]  Huajun Chen,et al.  Fluid flow and mixed convection heat transfer in a rotating curved pipe , 2003 .

[22]  Stuart W. Churchill,et al.  FULLY DEVELOPED LAMINAR CONVECTION FROM A HELICAL COIL , 1981 .

[23]  Hossein Shokouhmand,et al.  Optimal Reynolds number of laminar forced convection in a helical tube subjected to uniform wall temperature , 2007 .

[24]  P. Hatzikonstantinou,et al.  Numerical study of laminar fluid flow in a curved elliptic duct with internal fins , 2008 .

[25]  A. Chorin.  Numerical solution of the Navier-Stokes equations , 1968 .

[26]  H. Ishigaki.  Laminar flow in rotating curved pipes , 1996, Journal of Fluid Mechanics.

[27]  Hassan Peerhossaini,et al.  The effects of chaotic advection on heat transfer , 1997 .

[28]  Krishna D.P. Nigam,et al.  Numerical simulation of steady flow fields in coiled flow inverter , 2005 .

[29]  Hiroshi Ishigaki,et al.  Analogy between laminar flows in curved pipes and orthogonally rotating pipes , 1994, Journal of Fluid Mechanics.

[30]  Kobra Gharali,et al.  A numerical study of flow and heat transfer in internally finned rotating straight pipes and stationary curved pipes , 2006 .

[31]  A. Bejan,et al.  Entropy Generation Through Heat and Fluid Flow , 1983 .

[32]  W. R. Wagner,et al.  Correspondence: Grain boundaries in thin-film bicrystals of surface-reactive metals prepared by vacuum welding , 1974 .

[33]  K. Ting,et al.  Entropy generation and optimal analysis for laminar forced convection in curved rectangular ducts : A numerical study , 2006 .

[34]  Ahmed Z. Al-Garni,et al.  Effect of fouling on operational cost in pipe flow due to entropy generation , 2000 .

[35]  M. Adler,et al.  Strömung in gekrümmten Rohren , 1934 .

[36]  W. R. Dean.  LXXII. The stream-line motion of fluid in a curved pipe (Second paper) , 1928 .

[37]  T. H. Ko,et al.  Analysis of optimal Reynolds number for developing laminar forced convection in double sine ducts based on entropy generation minimization principle , 2006 .

[38]  Huajun Chen,et al.  Theoretical and numerical analysis of convective heat transfer in the rotating helical pipes , 2003 .

[39]  Rahim Khoshbakhti Saray,et al.  Investigation of potential of improvement of helical coils based on avoidable and unavoidable exergy , 2011 .

[40]  Somchai Wongwises,et al.  A review of flow and heat transfer characteristics in curved tubes , 2006 .

[41]  Stanley A. Berger,et al.  Laminar entrance flow in a curved pipe , 1984, Journal of Fluid Mechanics.

[42]  T. H. Ko,et al.  A numerical study on entropy generation and optimization for laminar forced convection in a rectangular curved duct with longitudinal ribs , 2006 .

[43]  K. Ting,et al.  Optimal Reynolds number for the fully developed laminar forced convection in a helical coiled tube , 2006 .

[44]  Sompop Jarungthammachote,et al.  Entropy generation analysis for fully developed laminar convection in hexagonal duct subjected to constant heat flux , 2010 .

[45]  M. T. Mehrabani,et al.  A numerical study of fluid flow and heat transfer in eccentric curved annuli , 2010 .

[46]  M.R.H. Nobari,et al.  A numerical investigation of developing flow and heat transfer in a curved pipe , 2009 .

[47]  Mohammad T. Khasawneh,et al.  Entropy generation due to laminar forced convection in the entrance region of a concentric annulus , 2004 .

[48]  R. Temam.  Navier-Stokes Equations , 1977 .