Computational fluid dynamics for cross‐ventilated airflow in an urban building

Abstract

In this study, the velocity field in a naturally ventilated building within an urban‐like array was explored using large‐eddy simulations. Reduced‐scale building models were used to examine the impacts of the geometric conditions in the surrounding buildings and cross‐ventilating windows on the flow statistics and instantaneous velocity fields in the sheltered building. The instantaneous velocity components averaged in the opening area were calculated for each condition of the building arrays and openings. The results indicate that the surrounding urban geometry significantly affects the turbulent opening velocities. Additionally, the three‐dimensional instantaneous velocity distributions within the target building clearly demonstrate considerable differences under the different building and opening conditions. Such differences also affect the mean, maximum, and minimum wind speeds within the indoor regions. Moreover, the distributions of the two‐point correlation coefficient (defined by the velocities normal to the windows at the center of the windward opening and inside the building) were compared for each condition. The strong correlations near the two openings indicate that the instantaneous velocity generated by the surrounding buildings is an important factor in determining the statistical and instantaneous features of indoor ventilating airflows.

A Review of Large-Eddy Simulation Cell Size Requirements for Indoor Flows

“…That is why in these studies the building is placed in a wind tunnel (see Figure 2a). The scale of the open area could vary from a small enclosure [26] through a repetitive pattern [7,48,49] to a section of a city [50,51].…”

“…With a few exceptions, the mentioned paper only investigated ventilation effectiveness. Hirose et al [7,10] conducted a thermal analysis of naturally ventilated rooms. It can also be seen that, when an additional thermal model is used, this helps only a little to gain better accuracy when compared to a similar study by Adachi et al [52].…”

“…Analysis of indoor air quality is a well-studied and frequently researched topic; many review articles also highlight that it has many relevant sub-levels, both in measurement [1][2][3] and in computational fluid modelling [1,[3][4][5][6][7].…”

Examining Wind Flow's Impact on Multi-Storey Buildings: A Quest for Quality Improvement

“…The application of computer modeling presents itself as a more cost-effective approach for investigating aerodynamic phenomena pertaining to airflow around buildings. This mode of simulating building aerodynamics, inclusive of the evaluation of natural and hybrid ventilation, stands as a pivotal component in the examination of wind pressure effects (Tominaga et al, 2016;Zhai et al, 2011;Chu, 2023;Van Hooff et al, 2017;Zhang et al, 2023;Perén et al, 2015;Shirzadi et al, 2018;Myroniuk et al, 2023;Hirose et al, 2022;Voznyak et al, 2022).…”

“…In the realm of computer modeling, the interplay between buildings assumes a significant role, given that their arrangement and configuration can alter the aerodynamic circumstances in densely populated urban areas. Additionally, evaluating the impact of external elements such as terrain and natural features holds import, as they can markedly influence and configure the wind patterns around the building (Chen et al, 2023;Blocken, 2018;Zhang et al, 2023;Hirose et al, 2022). This methodology, focusing on the evaluation of external factors' influence on aerodynamic phenomena, enables the modeling of urban microclimates at a pedestrian scale.…”