Natural convection in a cavity at high Rayleigh numbers

Thesis/Dissertation · Wed Jan 01 04:00:00 EST 1986

OSTI ID:7245539

Wan Hassan, M N

Numerical solution of a buoyancy-driving flow induced in a square enclosure by isothermally hot and cold vertical walls is presented. The calculations are performed for Prandtl number of 0.71 (air) and at Rayleigh number up to 10/sup 12/, using both laminar and turbulent theories. For the laminar flow, the equations derived using Boussinesq's approximation are solved by Newton's method and a sparse-matrix technique. At Rayleigh number of greater than 10/sup 9/, the computation utilizes the algebraic stress model. The calculation procedure for this turbulent flow employs Newton's method for the mean flow parameters as in the laminar case, an alternating direction implicit (ADI) method for the transport equations, and the Gauss-Seidel iterative technique for the algebraic stress relationships. The combination of these techniques seemed to converge reasonably well. The calculations are extended for the enclosure with diverse boundary conditions due to a local hot spot on the walls and/or floor of the enclosure. The computation is performed to obtain the velocity and temperature distributions and the heat transfer at the walls which are important in predicting thermal comfort and energy savings.

• Research Organization: Washington Univ., Seattle (USA)
• OSTI ID: 7245539
• Country of Publication: United States
• Language: English

Related Subjects

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATION
320100 -- Energy Conservation
Consumption
& Utilization-- Buildings
42 ENGINEERING
420400* -- Engineering-- Heat Transfer & Fluid Flow
BOUNDARY CONDITIONS
CAVITIES
CONVECTION
ENERGY CONSERVATION
ENERGY TRANSFER
FLUID FLOW
HEAT TRANSFER
ITERATIVE METHODS
LAMINAR FLOW
MASS TRANSFER
NATURAL CONVECTION
NEWTON METHOD
NUMERICAL SOLUTION
THERMAL COMFORT
TURBULENT FLOW
WALLS