4 research outputs found
Computational Analysis of Natural Ventilation Flows in Geodesic Dome Building in Hot Climates
For centuries, dome roofs were used in traditional houses in hot regions such as the Middle
East and Mediterranean basin due to its thermal advantages, structural benefits and availability
of construction materials. This article presents the computational modelling of the wind- and
buoyancy-induced ventilation in a geodesic dome building in a hot climate. The airflow and
temperature distributions and ventilation flow rates were predicted using Computational Fluid
Dynamics (CFD). The three-dimensional Reynolds-Averaged Navier-Stokes (RANS) equations were
solved using the CFD tool ANSYS FLUENT15. The standard k-epsilon was used as turbulence model.
The modelling was verified using grid sensitivity and flux balance analysis. In order to validate the
modelling method used in the current study, additional simulation of a similar domed-roof building
was conducted for comparison. For wind-induced ventilation, the dome building was modelled with
upper roof vents. For buoyancy-induced ventilation, the geometry was modelled with roof vents
and also with two windows open in the lower level. The results showed that using the upper roof
openings as a natural ventilation strategy during winter periods is advantageous and could reduce
the indoor temperature and also introduce fresh air. The results also revealed that natural ventilation
using roof vents cannot satisfy thermal requirements during hot summer periods and complementary
cooling solutions should be considered. The analysis showed that buoyancy-induced ventilation
model can still generate air movement inside the building during periods with no or very low wind
On the use of the homotopy analysis method for solving the problem of the flow and heat transfer in a liquid film over an unsteady stretching sheet
In this paper, the effects of viscous dissipation, nonuniform heat source/sink, magnetic field, and thermal radiation on the heat transfer characteristics of a thin liquid film flow over an unsteady stretching sheet are analyzed by the homotopy analysis method. The effects of various physical parameters on the heat transfer characteristics are found. The study shows that the thermal radiation parameter has a significant effect on the surface temperature. It is also found that nonuniform heat sinks are better suited for cooling purposes. Furthermore, the limiting cases are obtained and are found to be in good agreement with numerical results previously published by other authors.</p