Abstract
Two-dimensional, laminar, transitional and turbulent simulations were obtained by solving the fully-elliptic governing equations of the motion established by natural convection in channels, with Trombe Wall configuration, for different geometrical parameters and symmetrical heating. In transitional and turbulent cases, the low-Re k−ω turbulence model has been employed. To validate the numerical results, some comparisons with experimental results taken from literature have been carried out. Numerical results for the average Nusselt number and the non-dimensional induced mass-flow rate have been obtained for a wide and not yet covered range of the Rayleigh number varying from 105 to 1012. Correlations for the thermal and the mass-flow optimum wall-to-wall spacing have been presented. Finally, additional configurations including discrete heat sources have been studied, in order to obtain thermal and dynamic improvements. These intermediate devices were tested as turbulence generators, in the transitional range of Rayleigh numbers.
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Abbreviations
- A1, A2:
-
Bottom and top opening heights, respectively (Fig. 1) (m)
- A :
-
A1 or A2
- b :
-
Wall-to-wall spacing of the vertical channel (m) (Fig. 1)
- c p :
-
Specific heat at constant pressure (J kg−1K−1)
- E :
-
Thickness of the Trombe Wall (Fig. 1) (m)
- \(f_{\beta^*},\;f_{\beta}\) :
-
Turbulent factors depending on ξ k and ξω, Eqs. 10 and 13, respectively
- g :
-
Gravitational acceleration (m−2)
- Gr H :
-
Grashof number for isothermal cases, gβ(T w−T ∞) H 3/ν2
- Gr H :
-
Grashof number for heat flux cases, gβq H 4/ν2κ
- h x :
-
Local heat transfer coefficient, −κ(∂T/∂n)w/(T w−T ∞) (W m−2 K−1)
- I :
-
Turbulence intensity, Eq. 14
- k :
-
Turbulent kinetic energy, Eq. 6 (m2 s−2)
- H :
-
Height of the wall 1 (Fig. 1) (m)
- L :
-
Length of the room (Fig. 1) (m)
- M :
-
Non-dimensional mass-flow rate (m/ρν)
- m :
-
Two-dimensional mass-flow rate (kg m−1s−1)
- n :
-
Coordinate perpendicular to wall (m)
- Nu H :
-
Average Nusselt number based on H, isothermal cases, Eq. 17
- Nu H :
-
Average Nusselt number based on H, heat flux cases, Eq. 18
- Nu x :
-
Local Nusselt number, h x H/κ
- P :
-
Average reduced pressure (N m−2)
- Pr :
-
Prandtl number, μc p/κ
- q :
-
Wall heat flux (W m−2)
- R β, R k , R ω :
-
Constants of the turbulence model
- Ra H :
-
Rayleigh number based on H, (Gr H ) (Pr)
- Re t :
-
Turbulent Reynolds number, k/νω
- S ij :
-
Mean-strain tensor (s−1)
- T, T′:
-
Average and turbulent temperatures, respectively (K)
- \(-\overline{T^{\prime}u_{j}}\) :
-
Average turbulent heat flux (K m s−1)
- U j , u j :
-
Average and turbulent components of velocity, respectively (m s−1)
- \(-\overline{u_{i}u_{j}}\) :
-
Turbulent stress (m2 s−2)
- u τ :
-
Friction velocity, u τ = (τw/ρ)1/2 (m s−1)
- x, y :
-
Cartesian coordinates in the vertical and horizontal directions (m)
- y + :
-
ρy 1 u τ/μ, with y 1 the distance between the wall and the first grid point
- α, β*:
- \(\alpha_0^\ast,\) \(\alpha_0^\ast, \alpha_{\infty}, \alpha_0\) :
-
Constants of the turbulence model
- β:
-
Coefficient of thermal expansion, 1/T ∞ (K−1)
- δ ij :
-
Krönecker delta
- κ:
-
Thermal conductivity (W m−1 K−1)
- Λ:
-
Comparison thermal parameter, Eq. 25
- μ:
-
Viscosity (kg m−1 s−1)
- ν:
-
Kinematic viscosity, μ/ρ (m2s−1)
- ξ k , ξω :
-
Parameters of the turbulence model, Eqs. 10 and 13, respectively
- ρ:
-
Density (kg m−3)
- σ k , σω :
-
Constants of the turbulence model
- τw :
-
Wall shear stress (N m−2)
- Ψ:
-
Comparison mass-flow rate parameter, Eq. 25
- Ω ij :
-
Mean-rotation tensor (s−1)
- ω:
-
Specific dissipation rate of k (or turbulent frequency) (s−1)
- 1:
-
Outer wall (corresponding to glazing)
- 2:
-
Inner wall (corresponding to masonry wall)
- max:
-
Maximum
- opt:
-
Optimum
- ref:
-
Reference mesh
- t :
-
Turbulent
- w:
-
Wall
- ∞:
-
Ambient or reference conditions
- –:
-
Averaged value
References
Robert JF, Peube JL, Trombe F (1978) Experimental study of passive air-cooled flat-plate solar collectors: characteristics and working balance in the Obeillo solar houses. Energy Convers Heat Cool Vent Build 2:761–782
Akbari H, Borgers TR (1984) Free convective turbulent flows within the Trombe Wall channel. Solar Energy 33:253–264
Gan G (1998) A parametric study of Trombe Walls for passive cooling of buildings. Energy Build 27:37–43
Jubran BA, Hamdan MA, Manfalouti W (1991) Modelling free convection in a Trombe Wall. Renew Energy 1:351–360
Warrington RO, Ameel TA (1995) Experimental studies of natural convection in partitioned enclosures with a Trombe Wall geometry. ASME J. Solar Energy Eng 117:16–21
Smolec W, Thomas A (1994) Problems encountered in heat transfer studies of a Trombe Wall. Energy Convers Mgmt 35:483–491
Awbi HB (1994) Design considerations for naturally ventilated buildings. Renew Energy 5:1081–1090
Gan G, Riffat SB (1998) A numerical study of solar chimney for natural ventilation of buildings with heat recovery. Appl Therm Eng 18:1171–1187
Ong KS, Chow CC (2003) Performance of a solar chimney. Solar Energy 74:1–17
Chen ZD, Bandopadhayay P, Halldorsson J, Byrjalsen C, Heiselberg P, Li Y (2003) An experimental investigation of a solar chimney model with uniform wall heat flux. Build Environ 38:893–906
Onbasioglu H, Egrican AN (2002) Experimental approach to the thermal response of passive systems. Energy Convers Mngmt 43:2053–2065
Burek SAM, Habeb A (2007) Air flow and thermal efficiency characteristics in solar chimmneys and Trombe Walls. Energy Build 39:128–135
Lloyd JR, Sparrow EM (1970) On the instability of natural convection flow on inclined plates. J Fluid Mech 42:465–470
Miyamoto M, Katoh Y, Kurima J (1983) Turbulent free convection heat transfer from vertical parallel plates in air (heat transfer characteristics). NACSIS Electronic Library Service 1:1–7
Versteegh TA, Nieuwstadt FT (1999) A direct numerical simulation of natural convection between two infinite vertical differentially heated walls scaling laws and wall functions. Int J Heat Mass Transf 42:3673–3693
Henkes RAWM, Hoogendorn CJ (1995) Comparison exercise for computations of turbulent natural convection in enclosures. Numerical Heat Transf 28:59–78
Peng S, Davison L (1999) Computation of turbulent buoyant flows in enclosures with low–Reynolds number k−omega models. Int J Heat Fluid Flow 20:172–184
Fedorov AG, Viskanta R (1997) Turbulent natural convection heat transfer in an asymmetrically heated, vertical parallel-plate channel. Int J Heat Mass Transf 40:3849–3860
Ayinde TF, Said SAM, Habib MA (2006) Experimental investigation of turbulent natural convection flow in a channel. Heat Mass Transf 42:169–177
Badr HM, Habib MA, Anwar S, Ben-Mansour R, Said SAM (2006) Turbulent natural convection in vertical parallel-plate channels. Heat Mass Transf 43:73–84
da Silva AK, Gosselin L (2005) Optimal geometry of L and C-shaped channels for maximum heat transfer rate in natural convection. Int J Heat Mass Transf 48:609–620
Kaiser AS, Zamora B, Viedma A (2004) Correlation for Nusselt number in natural convection in vertical convergent channels at uniform wall temperature by a numerical investigation. Int J Heat Fluid Flow 25:671–682
Kolmogorov AN (1942) Equations of turbulent motion of an incompresible fluid. Izvestia Academy of Sciences, USSR, Physics 6:56–58
Wilcox DC (2003) Turbulence Modeling for CFD, 2nd edn. DCW Industries, USA
Patankar SV, Spalding DB (1972) A calculation procedure for heat, mass and momentum transfer in three-dimensional parabolic flows. Int J Heat Mass Transf 15:1787–1806
Van Leer B (1979) Towards the ultimate conservative difference scheme V. A second order sequel to Gadunov’s method. J Comput Phys 32:101–136
Kaiser AS (2005) Estudio de la transferencia de calor y de los flujos convectivos inducidos en una cubierta hídrico-solar, Ph.D. thesis, Universidad Politécnica de Cartagena, Spain
Kaiser AS, Zamora B, Viedma A (2009) Numerical correlation for natural convective flows in isothermal heated, inclined and convergent channels, for high Rayleigh numbers. Computers and Fluids (in press)
Guo ZY, Wu XB (1993) Thermal drag and critical heat flux for natural convection of air in vertical parallel plates. ASME J Heat Transf 115:124–129
Hajji A, Worek WM (1988) Analysis of combined fully developed natural convection heat and mass transfer between two inclined parallel plates. Int J Heat Mass Transf 31:1933–1940
Hernández J, Zamora B (2005) Effects of variable properties and non-uniform heating on natural convection flows in vertical channels. Int J Heat Mass Transf 48:793–807
la Pica A, Rodonò G, Volpes R (1993) An experimental investigation on natural convection of air in a vertical channel. Int J Heat Mass Transf 36:611–616
Ben Maad R, Belghith A (1992) The use of grid-generated turbulence to improve heat transfer in passive solar systems. Renew Energy 2:333–336
Acknowledgments
This research was supported by the ‘Dirección General de Investigación’ of ’Ministerio de Educación y Ciencia’ of Spanish Government, through DPI 2003-02719 Project. The computations were carried out on a HP-Compaq HPC160 platform, in the ’Servicio de Apoyo a la Investigación Tecnológica’, SAIT, of the Polythecnic University of Cartagena.
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Zamora, B., Kaiser, A.S. Thermal and dynamic optimization of the convective flow in Trombe Wall shaped channels by numerical investigation. Heat Mass Transfer 45, 1393–1407 (2009). https://doi.org/10.1007/s00231-009-0509-6
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DOI: https://doi.org/10.1007/s00231-009-0509-6