02Mar 2018

NUMERICAL MODELING OF FLOW NATURAL CONVECTION IN A THERMOSIPHON: THERMAL PANACHE.

  • Physics Solid and Materials Sciences Laboratory, Dept. of Physics, Cheikh Anta Diop University, Dakar, Senegal.
  • Fluid Mechanics and Applications Laboratory, Dept. of Physics, Cheikh Anta Diop University, Dakar, Senegal.
  • Hydraulics and Fluid Mechanics Laboratory, Dept. of Physics, Cheikh Anta Diop University, Dakar, Senegal.
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This present work follows a series of experimental studies on thermosiphon flows. In order to numerically highlight these experimental studies, we realized a geometric model from a vertical cylinder open at both ends, including a heated heat source with imposed heat flow. This source is placed at the entrance of the cylinder. The vertical walls of the cylinder are maintained adiabatic. The confinement of the fluid inside the cylinder causes a suction of the fresh air from below and thus transfers a thermal power absorbed by the system. There is a thermosiphon flow around the thermal plume. The profiles of the dynamic and thermal fields have shown that the structure of a plume generated by a heated source is closely influenced, mainly by the properties of the flow around this source. During the vertical evolution of the thermal plume, we have identified three different zones: An area, used to supply the plume with fresh air, is distinguished by temperature and velocity profiles, a zone of development of the flow of the buoyancy effect characterized by temperature profiles having a maximum on the plume axis and an area where the profiles flatten out, thus reflecting the establishment of the flow. The results showed an improvement in the energy absorbed by the fluid and an increase in the volume flow rate of the flow inside the cylinder characterized by the recirculation of the fluid.

  1. Agator ?M., Doan K.S. (1982) Turbulent structure of axi?symmetric thermal plume, Mech. Res. Commun. 9 159-164.
2.?????? Agator J.-M. et al. (1998) Characteristics of thermal turbulence in an axially symmetric plume, J. M?e. Theor. Appl. 3 577-599.3.?????? Agator J.M., (1983) Contribution to the study of the turbulent structure of a thermal plume with axial symmetry. Interaction of the plume with its limited environment, thesis, University of Poitiers,4.?????? Agator, J. M., Doan,K. S.? (1983) Spectral analysis of the thermal field of a turbulent plume with axial symmetry, C.R. Acad. Sc. Paris.5.?????? Ben Maad, R. (1995) Study of a natural convection flow in a heated vertical channel, thesis, University of Tunis.6.?????? Brahimi,M. (1987) Turbulent structure of thermal plumes-interaction, thesis, University of Poitiers. 7.?????? Brahimi,M. et al (1989) Turbulence structure of the interaction flow of two thermal plumes, int. J. Heat Mass Tran 32 1551-1559.8.?????? Brahimi,M. et al (1998) ?Medium and fluctuating fields of isolated or interacting thermal plumes, Rev. Brig. Therm. 315-316 236-243.
  1. Brahimi,, Doan, K.S. (1 986) Experimental and numerical predictions of the mean flow of a turbulent pure plume, Arch. Mech. Warszawa 38 51 9-528.
10.??? Dalbert ,A. M.et al. (1981) Laminar natural convection in a vertically heated constant flow channel, lnt. J. Heat Mass Tran. 24 1463-1473.11.??? Dehmani, L. et al. (l 996) Influence of strong density stratification on the entrainment of a turbulent axisymmetric plume, Exp. Fluids 21
  1. Dring,P., Gebhart, B. (1966) Transient natural convection from thin vertical cylinder, J. Heat Trans.-T. ASME ?246-248.
13.??? Guillou, B. (1984) Numerical and experimental study of the turbulent structure of a pure plume with axial symmetry, Thesis PhD, University of Poitiers.
  1. Kettleborough, C. (1972) Transient laminar free convection between heated vertical plates including entrance effects, International Journal of Heat and Mass Transfer 15883?896
  2. Mahmoud, A. O. M. et al. (2006) Improvement of the Vertical Dispersion of Pollutants Resulting From Chimneys by Thermosiphon Effect. American Journal of Environmental Sciences 2 66-73.
  3. Ramanathan, S. , Kumar, R. (1991) Correlations for natural convection between heated vertical plates, Journal of Heat Transfer (Transcations of the ASME (American Society of Mechanical Engineers), SeriesC) ,United States 113
  4. Wirtz, R., Stutzman,R. (1982) Experiments on free convection between vertical plates with symmetric heating, Journal of Heat Transfer 104.
18.??? Yahya, Z., Mbow, C. (2015) ?Study of the effect of thermosiphon on the vertical dispersion of pollutants, 22nd French Congress of Mechanics Lyon.

[Ousman Rilengar Godfroyd, Cheikh Mbow, Ngargoto Ngarmoundou, Vieux Boukhaly Traore, Mahamat Bichara Abderaman and Aboubaker Chedikh Beye. (2018); NUMERICAL MODELING OF FLOW NATURAL CONVECTION IN A THERMOSIPHON: THERMAL PANACHE. Int. J. of Adv. Res. 6 (Mar). 103-109] (ISSN 2320-5407). www.journalijar.com

Ousman Rilengar Godfroyd
Physics Solid and Materials Sciences Laboratory, Dept. of Physics, Cheikh Anta Diop University, Dakar, Senegal

DOI:

Article DOI: 10.21474/IJAR01/6655      
DOI URL: https://dx.doi.org/10.21474/IJAR01/6655

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