Effect of Gable Roof Angle on Streamlines and Pressure Coefficient for an Isolated Building

The airflow characteristics around and within an isolated gable roof building was investigated using CFD simulation based on steady RANS computation. Model validation and grid sensitivity analysis were conducted to ensure the reliability of the results. Three different roof pitches of gable roof namely 15º, 25º and 35º were considered in this study. The model validation results show well agreement with those of Tominaga et al. (2015). In general, the streamline and pressure coefficient were found to be significantly depending on the roof pitch. The streamline shows the velocity at the inlet opening and outlet opening increased as the roof pitch increase except the roof opening outlet increased between 15º and 25º then decreased between 25º and 35º. The spatial distribution of pressure coefficient at the windward side and the interior of the building decreased as the roof pitch increased. The difference in the flow fields of 25º and 35º roof pitch is large with the presence of window and roof opening relative to the difference between 15º and 25º roof pitch. In terms of spatial distribution of pressure coefficient and streamline, steeper roof pitch is more preferable.