THERMAL SCIENCE

International Scientific Journal

TURBULENCE TRANSITION THRESHOLD OF A BUOYANCY-DRIVEN FLOW OVER AN ISOTHERMAL VERTICAL WALL

ABSTRACT
The integral formalism has been developped in an attempt to predict the mathematical transition threshold from laminar to turbulent regimes in a free convection boundary-layer flow adjacent to an isothermal vertical wall and also to gain a better understanding in the prediction of the turbulence mechanism. The transition threshold is approached herein as the intersection of the two fully developped laminar and turbulent flow regimes. The transition for the isothermal wall condition is Prandtl number dependent and occurs differently depending on whether the dynamical or thermal viewpoints are considered. A change in the transition threshold behaviour is observed at Pr=20.
KEYWORDS
PAPER SUBMITTED: 2014-03-25
PAPER REVISED: 2014-03-28
PAPER ACCEPTED: 2014-05-20
PUBLISHED ONLINE: 2014-06-15
DOI REFERENCE: https://doi.org/10.2298/TSCI140325064P
CITATION EXPORT: view in browser or download as text file
THERMAL SCIENCE YEAR 2014, VOLUME 18, ISSUE 4, PAGES [1063 - 1068]
REFERENCES
  1. Varga, C., Fohanno, S., Polidori, G., Turbulent boundary-layer buoyant flow modeling over a wide Prandtl number range. Acta Mechanica, 172, (2004), pp. 65 - 73
  2. Popa, C.V., Fohanno, S., Nguyen, C.T., Polidori, G., On heat transfer in external natural convection flows using two nanofluids, International Journal of Thermal Sciences, 49 (6), (2010), pp. 901-908
  3. Arpaci, V.S., Kao, S.-H., Foundations of buoyancy driven heat transfer correlations. Journal of Heat Transfer, 123, (2001), pp. 1181-1184
  4. Mladin, E.C., Polidori, G., de Lorenzo, T., Revisited laminar free convection theory by integral method. Proc. of the 9th Conferentina Nationala de Termotechnica, Craiova, Romania, 1999, Vol. II, pp. 227-238
  5. Kakaç, S., Yener, Y., Convective heat transfer, CRC Press, Boca Raton, 1995.
  6. Ruckenstein, E., On the laminar and turbulent free convection heat transfer from a vertical plate over the entire range of Prandtl numbers. International Communication of Heat and Mass Transfer, 25, (1998), pp. 1009-1018
  7. Polidori, G., Mladin, E.-C., de Lorenzo, T., Extension de la méthode de Karman-Pohlhausen aux régimes transitoires de convection libre pour Pr > 0.6. C.R. Acad. Sci. Paris, IIb 328, (2000), pp. 763-766
  8. Polidori, G., Popa, C., Mai, T.H., Transient flow rate behavior in an external natural convection boundary layer. Mechanical Research Communication, 30, (2003), pp. 615-621
  9. Eckert, E.R.G., Jackson, T.W., Analysis of turbulent free-convection boundary layer on flat plate. NACA Report, 1015, (1950), pp. 1-7
  10. Lock, G.S.H., Trotter, F.J. deB., Observations on the structure of a turbulent free convection boundary layer. International Journal of Heat and Mass Transfer, 11, (1968), pp. 1225-1232

© 2019 Society of Thermal Engineers of Serbia. Published by the Vinča Institute of Nuclear Sciences, Belgrade, Serbia. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution-NonCommercial-NoDerivs 4.0 International licence