Passive cooling with cross-ventilation in a courtyard building improves indoor comfort and air quality. In this architectural concept, windows and doors are strategically placed on opposite or adjacent walls of a room that faces the central courtyard. The courtyard modifies the microclimate by creating pressure differences that allow air to move into the room and out through opposite openings. Air circulation and temperature regulation are improved by admitting cooler air from the shaded patio. The building orientation, courtyard size and layout, opening positions and proportions, and wind patterns all affect cross-ventilation. The study published in 2016 entitled “ Cross-ventilation of a Room in a Courtyard Building” is the basis of our simulation. (Reference Paper)

Figure 1: Configuration of courtyard building

Simulation Process

The courtyard building geometries are shown in Fig. 1. The building consists of a 9m × 9m × Hm 114 block with a central courtyard measuring 3m × 3m in plan. A room is located on the ground floor, having 115 windows measuring 1m×1m leading to the leeward side of the building and the courtyard, respectively. It then meticulously meshed using ICEM software, resulting in a structured grid established by 6000362 cells. The boundaries are all set based on the reference paper. Notably, the inlet velocity profile follows the equation:

where u∗ is the atmospheric boundary layer friction velocity, κ is the von Karman constant (taken as 0.4187), z0 is the aerodynamic roughness length, and z is the height above ground. This profile is applied via a user-defined function (UDF).

Post-processing

The CFD simulation of courtyard building ventilation shows complex airflow patterns needed to understand and optimize natural ventilation systems. The contour map shows air velocity distributions, with maximum speeds above the structure and intricate courtyard circulation. The simulation shows courtyard vortices, recirculation zones, and appropriate apertures between building components for cross-ventilation. This analysis shows how the courtyard design creates a microclimate that affects airflow and indoor comfort. The different airflow velocities and circulation patterns show how architectural design affects airflow. These natural airflow dynamics may help courtyard buildings decrease mechanical cooling systems, boosting energy efficiency and sustainability. This simulation helps architects and engineers create buildings that use natural airflow to improve interior air quality and reduce energy use.