3D Buoyancy Induced Heat Transfer in Triangular Solar Collector Having a Corrugated Bottom Wall

W. Aich

Abstract


A numerical study of the natural convection heat transfer and fluid flow in 3D triangular solar collector having a corrugated bottom wall has been carried out using finite volume method. The aim of the study is to investigate how buoyancy forces influence airflow and temperature patterns inside the collector heated from below and cooled on its inclined walls while vertical ones are assumed to be perfect thermal insulators. Rayleigh number is the main parameter which changes from 103 to 105 and Prandtl number is fixed at Pr=0.71. Results are reported in terms of particles trajectories, iso-surfaces of temperature, velocity magnitude and mean Nusselt number. It has been found that the flow structure is sensitive to the value of Rayleigh number and that heat transfer is enhanced with increasing of this parameter.


Keywords


natural convection; heat transfer; solar collector; Rayleigh number; Nusselt number

Full Text:

PDF

References


G. De Vahl Davis, “Natural convection in a square cavity: a benchmark numerical solution”, International Journal for Numerical Methods in Fluids, Vol. 3, No. 3, pp. 249–264, 1983

T. Fusegi, J. M. Hyun, K. Kuwahara, B. Farouk, “A numerical study of three dimensional natural convection in a differentially heated cubical enclosure”, International Journal of Heat and Mass Transfer, Vol. 34, No. 6, pp. 1543–1557, 1991

S. C. Tzeng, J. H. Liou, R. Y. Jou, “Numerical simulation-aided parametric analysis of natural convection in a roof of triangular enclosures”, Heat Transfer Engineering, Vol. 26, No. 8, pp. 69-79, 2005

A. Omri, J. Orfi, S. Ben Nasrallah, “Natural convection effects in solar stills”, Desalination, Vol. 183, No. 1-3, pp. 173–178, 2005

R. D. Flack, “The experimental measurement of natural convection heat transfer in triangular enclosures heated or cooled from bellow”, Journal of Heat Transfer, Vol. 102, No. 4, pp. 770–772, 1980

D. Poulikakos, A. Bejan, “Natural convection experiments in a triangular enclosure”, Journal of Heat Transfer, Vol. 105, No. 3, pp. 652–655, 1983

D. Poulikakos, A. Bejan, “The fluid dynamics of an attic space”, Journal of Fluid Mechanics, Vol. 131, pp. 251–269, 1983

H. Asan, L. Namli, “Numerical simulation of buoyant flow in a roof of triangular cross-section under winter day boundary conditions”, Energy and Buildings, Vol. 33, No. 7, pp. 753–757, 2001

H. Asan, L. Namli, “Laminar natural convection in a pitched roof of triangular cross-section: summer day boundary conditions”, Energy and Buildings, Vol. 33, No. 1, pp. 69–73, 2000

H. Salmun, “Convection patterns in a triangular domain”, International Journal of Heat and Mass Transfer, Vol. 38, No. 2, pp. 351–362, 1995

Y. Varol, A. Koca, H. F. Oztop, “Natural convection in a triangle enclosure with flush mounted heater on the wall”, International Communications in Heat and Mass Transfer, Vol. 33, No. 8, pp. 951–958, 2006

I. Hajri, A. Omri, S. Ben Nasrallah, “A numerical model for the simulation of double-diffusive natural convection in a triangular cavity using equal order and control volume based on the finite element method”, Desalination, Vol. 206, No. 1-3, pp. 579–588, 2007

E. Fuad Kent, E. Asmaz, S. Ozerbay, “Laminar natural convection in right triangular enclosures”, Heat and Mass Transfer, Vol. 44, pp. 187–200, 2007

M. M. Rahman, H. F. Oztop, A. Ahsan, M. A. Kalam, Y. Varol, “Double-diffusive natural convection in a triangular solar collector”, International Communications in Heat and Mass Transfer, Vol. 39, No. 2, pp. 264–269, 2012

E. Fuad Kent, “Laminar natural convection in isosceles triangular roofs in wintertime conditions”, Heat Transfer Engineering, Vol. 31, No. 13, pp. 1068–1081, 2010

E. Fuad Kent, “Numerical analysis of laminar natural convection in isosceles triangular enclosures”, Proceedings of the Institution of Mechanical Engineers, Part C: Journal of Mechanical Engineering Science, Vol. 223, No. 2, pp. 1157–1169, 2009

E. H. Ridouane, A. Campo, “Formation of a pitchfork bifurcation in thermal convection flow inside an isosceles triangular cavity”, Physics of Fluids, Vol. 18, No. 7, p. 074102, 2006

E. H. Ridouane, A. Campo, M. Hasnaoui, “Benefits derivable from connecting the bottom and top walls of attic enclosures with insulated vertical side walls”, Numerical Heat Transfer, Part A, Vol. 49, No. 2, pp. 175–193, 2006

E. Fuad Kent, “Numerical analysis of laminar natural convection in isosceles triangular enclosures for cold base and hot inclined walls”, Mechanics Research Communications, Vol. 36, No. 4, pp. 497–508, 2009

Y. Varol, H. F. Oztop, I. Pop, “Influence of inclination angle on buoyancy-driven convection in triangular enclosure filled with a fluid-saturated porous medium”, Heat and Mass Transfer, Vol. 44, pp. 617–624, 2008

E. H. Ridouane, A. Campo, M. Mc Garry, “Numerical computation of buoyant airflows confined to attic spaces under opposing hot and cold wall conditions”, International Journal of Thermal Sciences, Vol. 44, No. 10, pp. 944–952, 2005

E. H. Ridouane, A. Campo, “Heightened thermal convection as a result of splitting a square cavity diagonally in half”, Journal of Electronic Packaging, Vol. 128, No. 3, pp. 251–258, 2006

T. Basak, S. Roy, C. Thirumalesha, “Finite element analysis of natural convection in a triangular enclosure: effects of various thermal boundary conditions”, Chemical Engineering Science, Vol. 62, No. 9, pp. 2623–2640, 2007

S. Roy, T. Basak, C. Thirumalesha, C. Murali Krishna, “Finite element simulation on natural convection flow in a triangular enclosure due to uniform and non-uniform bottom heating”, Journal of Heat Transfer, Vol. 130, No. 3, p. 032501, 2008

E. H. Ridouane, A. Campo, J. Y. Chang, “Natural convection patterns in right-angled triangular cavities with heated vertical sides and cooled hypotenuses”, Journal of Heat Transfer , Vol. 127, No. 10, pp. 1181–1186, 2005

L. Kolsi, A. Abidi, M. N. Borjini, N. Daous, H. Ben Aissia, “Effect of an external magnetic field on the 3-D un steady natural convection in a cubical enclosure”, Numerical Heat Transfer, Part A, Vol. 51, No. 10, pp. 1003–1021, 2007

S. V. Patankar, Numerical Heat Transfer and Fluid Flow, CRC Press, 1981




eISSN: 1792-8036     pISSN: 2241-4487