simulation

Comfortable heating of rooms with large areas of external glazing is one of the most challenging issues in cold climate zones. The rule of thumb, in this case is locating the heating unit under the window. Modern architectural trends lead to an increase in the number of facilities with panoramic glazing. The common practice is to locate trench units in close proximity to glass for such facilities. This analysis shows that even fan-assisted trench heating cannot always cope with cold air screening of large windows.

Climate control of cabin aircraft is traditionally conditioned as a single unit by the environmental control system. Cabin temperature is controlled by the crew while passengers of the aircrafts have the control on the gaspers providing fresh air from the above head area. The small nozzles are difficult to reach and adjust to meet the passenger’s needs in terms of flow and direction. A more dedicated control over the near environment of each passenger can be beneficial in many situations.

Worldwide concern has been focused on the airborne disease of the COVID-19 pandemic. This study investigated the effect of the limited space air stability on the mechanism of SARS-CoV-2 spreading in the interpersonal breathing microenvironment using an unsteady computational fluid dynamics (CFD) method. A validated numerical model was employed to simulate the transient SARS-CoV-2 releasing process from normal breathing activity. The computational domain was divided into an interpersonal breathing microenvironment and the rest macroenvironment.

The ongoing covid-19 pandemic has drawn the attention on the importance of providing adequate fresh air to the occupants of the built environment, in particular in educational buildings. Higher ventilation rates and personal protection devices like facial masks are among the strategies and procedures to reduce the infection risk, allowing the fruition of school spaces despite the epidemic progression. Nevertheless, the problem of airborne transmission has been usually dealt with considering each environment alone and assuming steady state conditions.

In the UK, people spend over 90% of a day indoors. On weekdays, when outdoor air pollution concentrations peak in the morning and in the late afternoon, people are usually either in non-domestic premises or on their way to/from non-domestic premises. Therefore, establishing the distributions of indoor air pollutant concentrations in non-domestic environments is essential to model human exposure to hazardous air pollution, especially for vulnerable populations, such as schoolchildren or patients in hospitals.

The window/door opening behavior of occupants is a very important factor in determining the airflows and ventilation conditions in buildings, on which indoor pollutant concentration and transport are highly dependent. A two-room residence model was simulated in this study to analyze the airflow characteristics and pollutant transport under different window/door opening behaviors. Airflows were unidirectional and the residence could not be treated as a well-mixed zone when there were no temperature differences.

Purpose of the work

To analyze the impact of different leakages in buildings by way of simulations.

Method of approach

This paper presents a validation of airflow network (AFN) and computational fluid dynamics (CFD) simulations for a naturally ventilated office building using wind tunnel measurements as the reference for external pressure coefficients and effective airflow rate prediction. The CFD simulation model is also used to study the effect of partially open windows on the effective flow rate. This study also includes a design exercise for a naturally ventilated office building that analyses the differences in predicted average window open area for a typical weather year.

This special issue on Breakthrough of natural and hybrid ventilative cooling technologies: models and simulations, together with the connected issue Breakthrough of natural and hybrid ventilative cooling technologies: strategies, applications and case studies (vol. 16, issue 1), focuses on methods, tools and technologies for reaching the above-mentioned goal through the use of ventilative cooling, i.e. cooling by controlled natural ventilation (CNV). This strategy is one of the most cost-effective alternatives to air-conditioning systems.

People spend 70% -90% of their time indoors. Indoor air quality and human body’s health have a close relationship. With the advance of society, user comfort requirements for thermal environment are rising. Humidity is an important parameter for evaluating indoor air quality, which not only affects the thermal comfort of the human body but also seriously restricts the function of the building. In winter, the indoor humidity is dry. When using humidifier, the humidity around the humidifier is higher, but there is still a dry area in the room.