Three-Dimensional Simulation of Wind-Driven Ventilation Through a Windcatcher With Different Inlet Designs

Abstract

Windcatcher is an effective natural ventilation system, and its performance depends on several factors including wind speed and wind direction. It provides a comfortable and healthy indoor environment since the introduced fresh air decreases the moisture content and reduces the pollutant concentration. Since the wind speed and its direction are generally unpredictable, it is important to use special inlet forms and exits to increase the efficiency of a windcatcher. In this study, computational fluid dynamics (CFD) modeling is implemented using ansys fluent to investigate the airflow entering a three-dimensional room through a windcatcher with different inlet designs. Three designs are studied which are a uniform inlet, a divergent inlet, and a bulging-convergent inlet. The airflow pattern with all inlets provided adequate ventilation through the room. With all the applied wind velocities (1, 2, 3, and 6 m/s) at the domain's inlet, the divergent inlet shape has captured the highest airflow through the room and provided higher average velocity at 1.2 m high enhancing the thermal comfort where most of the human occupancy occurs. With 6 m/s wind velocity, the divergent inlet has captured 2.55% more flow rate compared to the uniform inlet and 4.70% compared to the bulging-convergent inlet, and it has also provided an average velocity at 1.2 m high in the room of 7.16% higher than the uniform inlet and 8.44% higher than the bulging-convergent inlet.

Parametric Enhancement of a Window-Windcatcher for Enhanced Thermal Comfort and Natural Ventilation

“…Recently, researchers have begun to explore the impact of external parameters on windcatchers, including building roof shapes, the effect of other structures, and upstream objects such as other windcatchers [17][18][19]. Efforts have also been made to enhance windcatcher ventilation efficiency by modifying its geometry [20], such as optimizing the windcatchers cross-section [21], their height [22], internal partitions and openings [23,24]. Moreover, studies have been conducted to integrate windcatchers with other natural ventilation systems, such as courtyards, wing walls, and solar chimneys [25][26][27].…”