Abstract
Thermal entrance region transient conjugate heat transfer is investigated involving fluid axial heat conduction for laminar pipe flows. Constant outer wall temperature boundary condition is assumed in the upstream region of a thick walled, two regional pipe. In the downstream region, the outer wall temperature is considered changing spatially in a periodical manner. The problem is solved numerically by a finite difference method. A parametric analysis is conducted in order to determine the effects of Peclet number, wall thickness ratio, wall-to-fluid thermal conductivity ratio, wall-to-fluid thermal diffusivity ratio and axial frequency on heat transfer characteristics. It is seen that, the results are highly dependent on the parameter values and the most effective ones are the Peclet number and the wall thickness ratio. It is observed that heat is transferred towards upstream due to the axial conduction in the wall and in the fluid and with increasing values for high axial frequency.
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Abbreviations
- a :
-
constant of discretization equation (Eq. 5)
- B :
-
dimensionless frequency
- c p :
-
specific heat at constant pressure, (kJ/kg·K)
- d :
-
thickness of the pipe wall, (m)
- F :
-
Factor
- Fo :
-
Fourier number
- Gz :
-
Graetz number
- h :
-
the distance between nodes (Eq. 9), (m)
- k :
-
thermal conductivity, (W/m·K)
- n :
-
total number of the nodes
- p :
-
order of computational method
- Pe :
-
Peclet number
- q :
-
heat flux, (W/m2·K)
- r :
-
radial coordinate, ratio of the distance between nodes or grid refinement ratio (Eq. 9)
- Re :
-
Reynolds number
- t :
-
time, (s)
- T :
-
temperature, (K)
- T o :
-
initial temperature of the system, (K)
- u :
-
axial velocity, (m/s)
- x :
-
axial coordinate, (m)
- α :
-
thermal diffusivity, (m2/s)
- β :
-
frequency, (Hz)
- δr :
-
radial position difference, (m)
- δx :
-
axial position difference, (m)
- Δr :
-
radial step size, (m)
- Δt :
-
time step increment, (s)
- ΔT :
-
amplitude of periodic temperature variation, (K)
- Δx :
-
axial step size, (m)
- ε :
-
relative error
- φ :
-
global variable for the RMS calculation
- ρ :
-
density, (kg/m3)
- b :
-
bulk
- c :
-
coarse
- f :
-
fluid, fine
- i :
-
inner wall
- i, j:
-
at nodal point i, j
- m:
-
mean
- max:
-
maximum
- o:
-
outer wall
- s :
-
safety
- w :
-
wall
- wf :
-
ratio of wall to fluid
- wi :
-
wall to fluid interface
- * :
-
dimensionless quantity
- 0 :
-
at previous time step
References
Wijeysundera N E 1986 Laminar forced convection in circular and flat ducts with wall axial conduction and external convection. Int. J. Heat Mass Transf. 29: 797–807 https://doi.org/10.1016/0017-9310(86)90131-6
Bilir S 1995 Laminar flow heat transfer in pipes including two dimensional wall and fluid axial conduction. Int. J. Heat Mass Transf. 38: 1619–1625 https://doi.org/10.1016/0017-9310(94)00269-2
Schutte D J, Rahman M M and Faghri A 1992 Transient conjugate heat transfer in a thick walled pipe with developing laminar flow. Numer. Heat Transf. Part A Appl. 21: 163–186 https://doi.org/10.1080/10407789108944871
Vick B, Ozisik M N and Ullrich D F 1983 Effects of axial conduction in laminar tube flow with convective boundaries. J. Frankl. Inst. 316: 159–173 https://doi.org/10.1016/0016-0032(83)90083-2
Lee S L and Hwang G J 1981 Finite element solution of low Peclet number fluid flow in round pipe with the Cauchy boundary condition. Can. J. Chem. Eng. 59: 760–765 https://doi.org/10.1002/cjce.5450590617
Ates A 1998 Transient conjugated heat transfer in thick walled pipes with convective boundary conditions. Ph.D. Thesis. Selcuk University, Konya, Turkey
Darici S 2004 Transient conjugated heat transfer in simultaneously developing laminar flow in thick walled pipes. Ph.D. Thesis. Selcuk University, Konya, Turkey
Hsu C-J 1965 Heat transfer in a round tube with sinusoidal wall heat flux distribution. AIChE J. 11: 690–695. https://doi.org/10.1002/aic.690110423
Patankar S V, Liu C H and Sparrow E M 1978 The periodic thermally developed regime in ducts with streamwise periodic wall temperature or heat flux. Int. J. Heat Mass Transf. 21: 557–565. https://doi.org/10.1016/0017-9310(78)90052-2
Li W and Kakac S 1991 Unsteady thermal entrance heat transfer in laminar flow with a periodic variation of inlet temperature. Int. J. Heat Mass Transf. 34(10): 2581–2592. https://doi.org/10.1016/0017-9310(91)90098-Y
Quaresma J N N and Cotta R M 1994 Exact solutions for thermally developing tube flow with variable wall heat flux. Int. Commun. Heat Mass Transf. 21(5): 729–742. https://doi.org/10.1016/0735-1933(94)90074-4
Yan W-M 1993 Transient conjugated heat transfer in channel flows with convection from the ambient. Int. J. Heat Mass Transf. 36: 1295–1301. https://doi.org/10.1016/S0017-9310(05)80098-5
Myong H K, Kasagi N and Hirata M 1990 Numerical prediction of turbulent pipe flow heat transfer for various Prandtl number fluids with the improved k-ε turbulence model. JSME Znt. JI. 32: 613–622. https://doi.org/10.1299/jsmeb1988.32.4_613
Barletta A and Zanchini E 1995 Laminar forced convection with sinusoidal wall heat flux distribution: axially periodic regime. Heat Mass Transf. 31: 41–48. https://doi.org/10.1007/BF02537420
Barletta A and Rossi di Schio E 1999 Effects of viscous dissipation on laminar forced convection with axially periodic wall heat flux. Heat Mass Transf. 35: 9–16. https://doi.org/10.1007/s002310050292
Barletta A and Rossi di Schio E 2000 Periodic forced convection with axial heat conduction in a circular duct. Int. J. Heat Mass Transf. 43: 2949–2960. https://doi.org/10.1016/S0017-9310(99)00360-9
Barletta A, Rossi di Schio E, Comini G and D’Agaro P 2009 Wall coupling effect in channel forced convection with streamwise periodic boundary heat flux variation. Int. J. Therm. Sci. 48: 699–707. https://doi.org/10.1016/j.ijthermalsci.2008.06.003
Zniber K, Oubarra A and Lahjomri J 2005 Analytical solution to the problem of heat transfer in an MHD flow inside a channel with prescribed sinusoidal wall heat flux. Energy Convers. Manag. 46: 1147–1163. https://doi.org/10.1016/j.enconman.2004.06.023
Barletta A and Magyari E 2007 Forced convection with viscous dissipation in the thermal entrance region of a circular duct with prescribed wall heat flux. Int. J. Heat Mass Transf. 50: 26–35. https://doi.org/10.1016/j.ijheatmasstransfer.2006.06.036
Barletta A, Rossi di Schio E, Comini G and D’Agaro P 2008 Conjugate forced convection heat transfer in a plane channel: Longitudinally periodic regime. Int. J. Therm. Sci. 47: 43–51. https://doi.org/10.1016/j.ijthermalsci.2007.01.013
Conti A, Lorenzini G and Jaluria Y 2012 Transient conjugate heat transfer in straight microchannels. Int. J. Heat Mass Transf. 55: 7532–7543. https://doi.org/10.1016/j.ijheatmasstransfer.2012.07.046
Altun A H, Bilir S and Ates A 2016 Transient conjugated heat transfer in thermally developing laminar flow in thick walled pipes and minipipes with time periodically varying wall temperature boundary condition. Int. J. Heat Mass Transf. 92: 643–657. https://doi.org/10.1016/j.ijheatmasstransfer.2015.09.011
Aydin O, Avci M, Bali T and Arıcı M E 2014 Conjugate heat transfer in a duct with an axially varying heat flux. Int. J. Heat Mass Transf. 76: 385–392. https://doi.org/10.1016/j.ijheatmasstransfer.2014.04.062
Aydın O and Avcı M 2015 Laminar forced convective slip flow in a microduct with a sinusoidally varying heat flux in axial direction. Int. J. Heat Mass Transf. 89: 606–612. https://doi.org/10.1016/j.ijheatmasstransfer.2015.05.056
Zhu X W, Fu Y H and Zhao J Q 2016 A novel wavy-tape insert configuration for pipe heat transfer augmentation. Energy Convers. Manag. 127: 140–148. https://doi.org/10.1016/j.enconman.2016.09.006
Bilir S 1992 Numerical solution of Graetz problem with axial conduction. Numer. Heat Transf. Part A Appl. 21: 493–500. https://doi.org/10.1080/10407789208944889
Patankar S V 1980 Chapter 4 Numerical heat transfer and fluid flow. In: W J Minkowycz and A M Sparrow (eds), Newyork: Hemisphere Publishing Corporation, McGraw-Hill Book Company, pp. 44–47
Bilir S 2002 Transient conjugated heat transfer in pipes involving two-dimensional wall and axial fluid conduction. Int. J. Heat Mass Transf. 45: 1781–1788. https://doi.org/10.1016/S0017-9310(01)00270-8
Bilir S and Ates A 2003 Transient conjugated heat transfer in thick walled pipes with convective boundary conditions. Int. J. Heat Mass Transf. 46(14): 2701–2709. https://doi.org/10.1016/S0017-9310(03)00032-2
Ates A, Darici S and Bilir S 2010 Unsteady conjugated heat transfer in thick walled pipes involving two-dimensional wall and axial fluid conduction with uniform heat flux boundary condition. Int. J. Heat Mass Transf. 53(23–24): 5058–5064. https://doi.org/10.1016/j.ijheatmasstransfer.2010.07.059
Darici S, Bilir S and Ates A 2015 Transient conjugated heat transfer for simultaneously developing laminar flow in thick walled pipes and minipipes. Int. J. Heat Mass Transf. 84: 1040–1048. http://dx.doi.org/10.1016/j.ijheatmasstransfer.2014.12.049
Atmaca U, Bilir S and Ates A 2017 Effects of wall conjugation and fluid axial conduction in circumferentially partly heated pipes and minipipes. Heat Transf. Res. 48(16): 1433–1458. https://doi.org/10.1615/heattransres.2017017830
Roache P J 1994 Perspective: A method for uniform reporting of grid refinement studies. J. Fluids Eng. 116(3): 405–413. https://doi.org/10.1115/1.2910291
Faghri M and Sparrow E M 1980 Forced convection in a horizontal pipe subjected to nonlinear external natural convection and to external radiation. Int. J. Heat Mass Transf. 23(6): 861–872. https://doi.org/10.1016/0017-9310(80)90041-1
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Ateş, A. Transient conjugated heat transfer in thick walled pipes with axially periodic surface temperature in downstream region. Sādhanā 44, 82 (2019). https://doi.org/10.1007/s12046-019-1079-z
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DOI: https://doi.org/10.1007/s12046-019-1079-z