High-performance building: Sensitivity analysis for simulating different combinations of components of a two-sided windcatcher

Abstract

Traditional windcatchers with massive structures were used to capture the local wind stream to improve occupant thermal comfort. To obtain smaller configurations with enhanced/similar performance metrics, the individual components of a conventional windcatcher, i.e. inlet opening, divider, outlet, and height are widely studied in the literature. This work aims to (1) use an in-house developed and verified numerical model to explore the impact of combinations of components of a windcatcher on its performance and (2) introduce the implementation of nozzles with different configurations in obtaining a flexible design for an extended range of applications. A 3-dimensional steady-state computational fluid dynamics simulation with a shear-stress-transport k-ω turbulence model is used to explore the flow characteristics. The airflow distribution throughout the system and mass flow rate at the outlet of a reference case, a well-studied two-sided windcatcher design, are validated with published wind tunnel experimental data. The verified model is then used for the following analyses. The results highlight the role of different windcatcher individual components and their combinations on the developed pressure gradients inside the windcatcher. A desired combination of components to improve the aerodynamic performance of the reference case is introduced: the integration of a convergent-divergent nozzle with finned-curved inlet openings along with the longest dividers increase the induced air mass flow rate up to 13%. The maximum flow velocity is increased by 45% at the nozzle throat area for the identified windcatcher configuration. The outcomes of this research can be used by engineers and researchers to enhance building-integrated windcatcher designs.