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Numerical Simulation of Mixed Convection Airflow Under
a Dome-Shaped Roof
By: Masih KhoshabSupervisor: Dr. A.A. Dehghan
Domed Roofs
One of the typical underground cold water storage with domed roof equipped with wind catchers (Baadgir)
Domed Roofs & underground cold water storage
One of the typical underground cold water storage with domed roof equipped with wind catchers (Baadgir)
Domed Roofs & underground cold water storage
• Finite-Volume Method
• Staggered Grid
• SIMPLER Algorithm
• Scheme ADI (Implicit Line-by-Line)
• Turbulence Modeling (LRN K-ω model of Wilcox)
Solution Procedure
Validation and Verification
Concentric Isothermal SpheresNatural convection in tall cavityMixed convection in square cavity
Buoyancy-Induced FlowBetween Two Concentric Isothermal
Spheres
Problem Definition
Physical Model and Coordinates System
5107.392Ra 2.17R*
510261.2Ra *R =1.78Oi
rr
Numerical & Experimental Results
*R 2, Pr=0.72 6Ra 1 10 5 10
Effects of Rayleigh Number
Effects of Rayleigh Number
*R 1.5, Pr=0.73 6Ra 1 10 1 10
*R 1.2, Pr=0.73 6Ra 1 10 1 10
Effects of Rayleigh Number
Variation of Nusselt Number with Rayleigh Number
Natural convection in tall cavityMixed convection in square cavity
Natural convection in tall cavity
From Peng and Davidson, J. Heat Fluid Flow 20, 172–184 (1999)
Streamlines and Isothermal Contours
Streamline (right) and Isothermal Contours (left)
Peng and Davidson, J. Heat Fluid Flow 20, 172–184 (1999).Cheesewright et al., HTD 60, ASME, pp. 75–81, (1986).
Profiles at Midsection and Nu Number
Mixed convection in square cavity
Mixed convection in square cavity
From Peng and Davidson, J. Heat Fluid Flow 20, 172–184 (1999)Blay et al., HTD 213, ASME (1992)
Velocity Profile at Midsection
Temperature Profile at Midsection
Turbulence Kinetic Energy Profile at Midsection
Dome-Shaped Roof
Spherical Coordinates
Effects of Grashof Number
6 10Gr=1 10 1 10 4Re=1 10
Streamline (right) and Isothermal Contours (left)
Effects of Reynolds Number
3 4Re=5 10 5 10 6Gr=1 10Streamline (right) and Isothermal Contours (left)
Modifications and Accomplishments
• I extended the solver for Micropolar fluid and Nanofluid flows.
• Yuri Feldman and Tim Colonius,International Journal of Heat and Mass Transfer 64, 514–525, (2013).
• Two MSc. Student.
