Design and performance comparison of two patterns of wind-catcher for a semi-enclosed courtyard

The main focal point of this work is to provide an enhanced indoor air quality (IAQ) using natural ventilation system called wind-catcher and also to cut the energy consumed by mechanical HVAC systems. This paper looks into the operation of two patterns of wind-catcher in a semi-enclosed courtyard on the top level of the engineering school at Sultan Qaboos University, Oman. The wind speed, direction and roughness length in the region of SQU were used as the inlet and boundary conditions. Computational Fluid Dynamics (CFD) analysis was performed using ANSYS FLUENT with a standard k-epsilon model to generate a homogenous neutral ABL at the inlet. This study provides a comparison of airflow distribution inside the courtyard with two modified wind-catcher designs to provide better indoor air quality. The primary focus is on the air stream distribution. The best possible flow rate of 6056 L/s was achieved for reference velocity 4 m/s at reference height 50m. This rate is more eminent than the minimum requirement suggested by ASHRAE standard 62.1-2013. Also air change per hour (ACH) for the same condition was around 108.