Abstract
Natural convection experiments were carried out on inclined plates. A copper sulfate electroplating system was adopted to simulate heat transfer based on analogy. The lengths of the copper plates were 0.1 and 0.35 m, corresponding to Grashof numbers of 8.06 × 107 and 3.45 × 109. The inclination of the plates varied from upward-facing (UF) horizontal to downward-facing (DF) horizontal. Test results for the DF plate agreed well with Rich’s theory, that the Nusselt number can be calculated by replacing g with g cosθ in the heat transfer correlation for a vertical plate and those for the UF plate reveal that the development of the boundary layer and the flow separation occurs repeatedly for the whole plate length. The copper-plating patterns for the UF plates visualized the location of flow separation. The empirical correlation predicting the critical distance and the heat transfer correlations was proposed.
Similar content being viewed by others
Abbreviations
- C b :
-
Concentration in the bulk (mol/m3)
- D m :
-
Diffusivity (m2/s)
- F :
-
Faraday constant, 96,485 (C/mol)
- Gr L :
-
Grashof number (gβΔTL 3/ν 2)
- Gr C :
-
Critical Grashof number (gβΔTL 3 c /ν 2)
- Gr * :
-
Modified Grashof number (gβq w L 4/kν 2)
- g :
-
Gravitational acceleration (m/s2)
- h h :
-
Heat transfer coefficient (W/m2 K)
- h m :
-
Mass transfer coefficient (m/s)
- I :
-
Electric current (A)
- I lim :
-
Limiting current density (A/m2)
- k :
-
Thermal conductivity (W/m K)
- L :
-
Length of cathode (m)
- L C :
-
Critical length (m)
- L R :
-
Remaining length (m)
- N :
-
Number of separation (m)
- Nu L :
-
Nusselt number (h h L/k)
- n :
-
Number of electrons in charge transfer reaction
- Pr :
-
Prandtl number (ν/α)
- Ra L :
-
Rayleigh number (gβΔTL 3/αν)
- Ra * :
-
Modified Rayleigh number (gβq w L 4/kαν)
- Sc :
-
Schmidt number (ν/D m )
- Sh L :
-
Sherwood number (h m L/D m )
- t n :
-
Transference number
- U x :
-
Uncertainty of x
- α :
-
Thermal diffusivity (m2/s)
- β :
-
Volume expansion coefficient (1/K)
- γ :
-
Dispersion coefficient
- θ :
-
Inclined angle measured from the vertical (°)
- μ :
-
Viscosity (kg/m s)
- ν :
-
Kinematic viscosity (m2/s)
- ρ :
-
Density (kg/m3)
References
Rich BR (1953) An investigation of heat transfer from an inclined flat plate in free convection. Trans ASME 75:489–499
Fussey DE, Warneford IP (1978) Free convection from a downward facing inclined flat plate. Int J Heat Mass Transf 21:119–126
Vliet GC, Ross DC (1975) Turbulent natural convection on upward and downward facing inclined constant heat flux surfaces. J Heat Transf 97:549–554
Komori K, Kito S, Nakamura T, Inaguma Y, Inagaki T (2001) Fluid flow and heat transfer in the transition process of natural convection over an inclined plate. Heat Transf Asian Res 30:648–659
Kimura F, Kitamura K, Yamaguchi M, Asami T (2003) Fluid flow and heat transfer of natural convection adjacent to upward-facing inclined heated plate. Heat Transf Asian Res 32:278–291
Lloyd JR, Sparrow EM (1970) On the instability of natural convection flow on inclined plates. J Fluid Mech 42:465–470
Fujii T, Imura H (1972) Natural convection heat transfer from a plate with arbitrary inclination. Int J Heat Mass Transf 15:755–767
Chun YH, Choi CK (1992) Experimental study of natural convection over inclined plates by electrochemical technique. Hwahak Konghak 30:26–33
Le Fevre EJ, Ede AJ (1956) Laminar free convection from the outer surface of a vertical circular cylinder. In: Proceedings of the 9th international congress applied mechanics, Brussels, pp 175–183
Fouad MG, Ibl N (1960) Natural convection mass transfer at vertical electrodes under turbulent flow conditions. Electrochim Acta 3:233–243
McAdams WH (1954) Heat transmission, 3rd edn. McGraw-Hill, New York, pp 175–177
Vliet GC (1969) Natural convection local heat transfer on constant heat flux inclined surfaces. J Heat Mass Transf 91:511–516
Al-Arabi M, Sakr B (1988) Natural convection heat transfer from inclined isothermal plates. Int J Heat Mass Transf 31:559–566
Frank PI, David PD, Theodore LB, Adrienne SL (2007) Fundamentals of heat and mass transfer. John Wiley & Sons (Asia) Pte Ltd, pp 574–577
Bejan A, Kraus AD (1995) Heat transfer handbook. Wiley, New York, pp 268–287
Levich VG (1962) Physicochemical hydrodynamics. Prentice Hall, Englewood Cliffs, NJ
Agar JN (1947) Diffusion and convection at electrodes. Discuss Faraday Soc 26:27–37
Selman JR, Tobias CW (1978) Advances in chemical engineering, vol 10. Academic Press, New York, pp 212–279
Fenech EJ, Tobias CW (1960) Mass transfer by free convection at horizontal electrodes. Electrochim Acta 2:311–325
Chung BJ, Heo JH, Kim MH, Kang GU (2011) The effect of top and bottom lids on natural convection inside a vertical cylinder. Int J Heat Mass Transf 54:135–141
Kang GU, Chung BJ (2010) The experimental study on transition criteria of natural convection inside a vertical pipe. Int Commun Heat Mass Transf 37:1057–1063
Kang KU, Chung BJ (2010) The effects of the anode size and position on the limiting currents of natural convection mass transfer experiments in a vertical pipe. Trans KSME B 34:1–8
Ko BJ, Chung BJ (2010) Study on the laminar mixed convection of developing flow in a vertical pipe. Trans KSME B 34:481–489
Ko BJ, Lee WJ, Chung BJ (2010) Turbulent mixed convection heat transfer experiments in a vertical cylinder using analogy concept. Nucl Eng Des 240:3967–3973
Ko SH, Moon DW, Chung BJ (2006) Applications of electroplating method for heat transfer studies using analogy concept. Nucl Eng Technol 38:251–258
Heo JH, Chung BJ (2012) Natural convection heat transfer on the outer surface of inclined cylinders. Chem Eng Sci 73:366–372
Ko BJ, Kim MH, Chung BJ (2012) An experimental study on the transition criteria of natural convective flows. J Mech Sci Technol 26:1227–1234
Coleman HW, Steele WG (1999) Experimental and uncertainty analysis for engineers, 2nd edn. Wiley, New York
Acknowledgments
This study was sponsored by the Ministry of Science, ICT & Future Planning (MSIP) and was supported by Nuclear Research & Development program grant funded by the National Research Foundation (NRF) (Grant Code: 2013M2A8A2025997).
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Lim, CK., Chung, BJ. Natural convection experiments on the upward and downward faces of inclined plates using an electroplating system. Heat Mass Transfer 51, 713–722 (2015). https://doi.org/10.1007/s00231-014-1450-x
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s00231-014-1450-x