Buoyancy-driven Thermal and Flow Characteristics in Gaps between Two Glasses of Multi-framed Window

Abstract: In building industry, both the beauty of the building facades and cost-effectiveness of the building are critical to occupants. The occupants long for the building that is more beautiful as well as comfort with low cost. For the beautiful facade, the more glasses are used and sometimes, the building covered with glasses. However, no glasses can prevent the heat energy flows out completely. Under the circumstance, to prevent the energy leakage through the window glass, multiple-framed windows are employed in architectural engineering in Korea. The gap between glasses is inevitable and the buoyancy-driven air flow in the gap between window glasses is one critical key for the heat transfer through the window. A numerical program for the air flow in the gap is developed considering gravity (buoyancy-driven momentum). Both the energy based on the temperature and the incompressible Navier-Stokes equations by using Boussinesq assumption are employed. A finite volume method based on the second-order accuracy is used to discretize, and a SIMPLE algorithm is employed to solve the pressure field instead of a decoupled continuity equation. The numerical validations are performed, and the reliability of the method is assessed. The characteristics of heat transfer and flow in three gaps are closely investigated with the developed code.