Characteristics of Heat Transfer of Buoyancy-driven Rectangular Cavity with Various Aspect Ratios

AUTHOR(S):

Juhee Lee

KEYWORDS

Natural convection, Aspect ratio, Computational methods, Heat transfer, Cavity

ABSTRACT

Energy saving is one of the global issues in these days. To improve insulation performance for energy saving, multiple layers of the window glasses and walls are employed in architectural engineering. In designing energy-saving buildings, the heat transfer through a large windows or wall becomes critical. The buoyancy-driven air flow between window glasses or wall layers is a key of the heat transfer in the building. A numerical code for the heat transfer problem is developed considering gravity and buoyancy-driven momentum at Ra=1e5. A temperature-based energy equation is combined with the incompressible Navier-Stokes equation by using Boussinesq approximation. A finite volume method based on a fully-implicit second-order is used to discretize and solve the momentum equation on unstructured grids composed of arbitrary-shaped cells. The integrations of the governing equation are discretized in the finite volume manner using a collocated arrangement of variables. A SIMPLE algorithm is employed to solve the pressure and momentum equations for the incompressible flow instead of a decoupled continuity equation. The numerical methods are verified and the reliability of the method is assessed. The characteristics of heat transfer and flow in cavity with various aspect ratios are closely investigated with the newly developed code.

Cite this paper

Juhee Lee. (2017) Characteristics of Heat Transfer of Buoyancy-driven Rectangular Cavity with Various Aspect Ratios. International Journal of Mechanical Engineering, 2, 5-10