Yifan Fan

Yifan Fan
Zhejiang University | ZJU · Department of Architecture

PhD

About

33
Publications
7,287
Reads
How we measure 'reads'
A 'read' is counted each time someone views a publication summary (such as the title, abstract, and list of authors), clicks on a figure, or views or downloads the full-text. Learn more
578
Citations

Publications

Publications (33)
Preprint
Moisture in the building envelopes increase the energy consumption of buildings and induce mould growth, which may be amplified within the area of thermal bridges due to their different hygrothermal properties and complex structures. In this study, we aimed to (1) reveal the moisture distribution in the typical thermal bridge (i.e., wall-to-floor t...
Preprint
Moisture in the building envelopes increase the energy consumption of buildings and induce mould growth, which may be amplified within the area of thermal bridges due to their different hygrothermal properties and complex structures. In this study, we aimed to (1) reveal the moisture distribution in the typical thermal bridges (i.e., wall-to-floor...
Article
Full-text available
The moisture modifies the characteristics of heat transfer in building envelopes. Multiple factors, including the distinct hygric properties of various material, gravity, etc ., affect the moisture content, resulting in a non-uniform distribution of water vapour in different parts of the envelope (e.g. column, beam, the main part of exterior walls)...
Article
Full-text available
Natural convection arising over vertical and horizontal heated flat surfaces is one of the most ubiquitous flows at a range of spatiotemporal scales. Despite significant developments over more than a century contributing to our fundamental understanding of heat transfer in natural convection boundary layers, certain “hidden” characteristics of thes...
Article
Urban surface composition is key information for global carbon emission estimation, mesoscale numerical simulations, and outdoor environment studies at both city and neighborhood scales. High spatial-resolution satellite imagery can provide accurate urban surface data. Due to the large volume of data, it is time-consuming to extract manually inform...
Article
Effective infection prevention and control measures are required in the intensive care units of hospitals, as these areas have a high incidence of nosocomial infections. Adopting proper ventilation pattern that is efficient in pollutant removal is important for controlling the spread of infectious diseases. In this study, the computational fluid dy...
Article
Severe haze episodes and extreme heat events are both related to the strong inversion in the atmospheric boundary layer. Inversion breakup is the main mechanism to alleviate the accumulation of heat or pollutants, especially in urban areas. However, the physical process and turbulent flow structures of inversion breakup remain unclear. In this stud...
Article
Full-text available
The amount of heat loss through thermal bridges increases with the improvement of the thermal insulation performance of the building exterior wall, making thermal bridges vulnerable points of thermal insulation. The wall-to-floor thermal bridge (WFTB) takes the most considerable fraction on the building envelope and has the largest heat flux. In th...
Article
Natural convection flow above a heated horizontal area plays a major role in energy utilisation, indoor/outdoor thermal environment, city ventilation and pollutant dispersion. Such natural convection can present different flow patterns, and identifying the type of flow pattern is crucial for determining the bulk heat transfer coefficient. Water tan...
Article
The severity of urban air pollution problems in China increases with the city's size and population density. Outdoor air pollution not only affects indoor air quality but also increases building energy consumption. We analyzed the characteristics of urban air pollution in China based on long-period monitoring data with high temporal resolution (hou...
Article
When background wind is moderate, urban environment may face great challenges as removal ability of airborne pollutants, anthropogenic heat and moisture reduces. Under this condition, buoyancy-driven flow can break the dominant role of the background wind and affect the urban environment greatly. Knowledge of buoyant flow dynamics is essential for...
Article
The adverse environmental impacts of the urban heat island (UHI) phenomenon have been known amid rapid urbanization in many parts of the world. UHI-induced circulation (UHIC) can affect pollutant dispersion and heat exchange. An UHIC can transform into an urban plume (or perturbed UHIC) in the presence of regional wind. To understand the urban plum...
Article
Natural convection over an isolated horizontal plate in a stably stratified background condition is fundamental and challenging in industrial, atmospheric, geographical, and oceanic environmental studies, which, however, is still lack of investigation. In this study, the water tank modelling experiment with two main techniques, Thermal Image Veloci...
Article
Air pollution and extreme heat waves are among the major environmental challenges faced by modern cities. Stable stratification and temperature inversion help to trap urban airborne pollutants and produce a strong urban heat island intensity. Such adverse effects can disappear when the buoyancy flows introduced by the city heat is sufficiently stro...
Article
Extreme heatwaves and air pollution in urban areas often occur in calm and stable background conditions. In such situations, urban heat dome flows are induced by the urban heat island (UHI) effect, which has a strong influence on the urban thermal and wind environment. Cities have various shapes, but most studies of urban heat island circulation ha...
Article
This paper presents a numerical study of two interacting urban heat island circulations (UHICs) in the presence of weak background wind. The Weather Research and Forecasting (WRF) model was used with ideal settings without the Earth's rotation effect. UHICs were simulated over circular cities of the same size arranged in tandem or side by side with...
Article
The paper performs an investigation on multi-scale coherent structures that exist in different flow patterns of triple interacting plumes. Time-averaged and turbulent flow characteristics are first obtained by the two-dimensional (2-D) particle image velocimetry (PIV) technique. Proper orthogonal decomposition (POD) method is then applied to extrac...
Article
Full-text available
The mean and random components of the velocity field at very low wind speeds in a convective boundary layer (CBL) over a wide urban area are dominated by large eddy structures—either turbulent plumes or puffs. In the mixed layer at either side of the edges of urban areas, local mean recirculating flows are generated by sharp horizontal temperature...
Article
This paper presents a systematic experimental study on stream-wise flow development and spatial structure of triple buoyant plumes. Two-dimensional Particle Image Velocimetry (2-D PIV) is employed to resolve velocity fields. Stream-wise axial velocity profiles, flow structure, flow region parameters, and self-similarity properties are analyzed at d...
Article
The Weather Research and Forecasting (WRF) Model is used to study the interaction between urban heat island circulation (UHIC) and its background wind. Two distinct wind regimes are found depending on the ratio of the horizontal convective scale velocity to the background velocity, which is referred to as the buoyancy velocity ratio. When the buoya...
Article
Full-text available
High-rise deep street canyons usually experience poor ventilation and large vehicular pollutant exposure to residents in near-road buildings. Investigations are still required to clarify the flow and dispersion mechanisms in deep street canyons and explore techniques to reduce such large pollutant exposure. By conducting computational fluid dynamic...
Article
Full-text available
Sustainable urban design is an effective way to improve urban ventilation and reduce vehicular pollutant exposure to urban residents. This paper investigated the impacts of urban open space and ‘lift-up’ building design on vehicular CO (carbon monoxide) exposure in typical three-dimensional (3D) urban canopy layer (UCL) models under neutral atmosph...
Article
Urban heat island-induced circulation, or urban heat dome flow, significantly influences urban thermal environments and air quality in calm wind conditions with stable stratification. An urban heat dome is characterized by convergent inflow at the ground level, divergent outflow at the upper level and upward flow over the city center in calm condit...
Article
Urban heat island circulation (UHIC), commonly established under calm background conditions, is important for understanding the accumulation of pollutants and heat in a city. In a city cluster in which multiple cities exist in proximity, the resulting multiple UHICs can interact. As many city clusters continue to grow in size and in number, particu...
Article
Full-text available
Urban heat dome flow, which is also referred to as urban heat island circulation, is important for urban ventilation and pollutant transport between adjacent cities when the background wind is weak or absent. A “dome-shaped” profile can form at the upper boundary of the urban heat island circulation. The horizontal extent of the heat dome is an imp...
Article
The natural convective wall flows along an exterior wall of a 16-story high-rise building were measured in Guangzhou city, China. The Rayleigh number reached as high as 10¹⁴. The correlation between the vertical velocity along the wall and the temperature difference between the wall surface and ambient air was analyzed. The diurnal variation of the...
Article
Full-text available
In the buoyancy and turbulence-driven atmospheric circulations (BTDAC) that occur over urban areas where the approach means wind speeds are very low (less than turbulent fluctuations and typically <. 3. m/sec), the surface temperatures are significantly higher than those in the external rural areas, and the atmosphere above the mixing layer is stab...
Article
Full-text available
Urban heat island circulation establishes an urban dome under stable stratification and no background wind conditions. Small-scale water models have been a very useful tool in the exploration of the mechanisms by which urban domes and their associated wind flows are formed. Data are available from a number of water-tank heat island models. Data fro...
Article
The flow caused by natural convection adjacent to a heated vertical wall (wall flow) is an important mechanism in the creation of wind flows in a city when the background wind is weak. The wall flows along a 16-storey building were measured in Guangzhou, China. Fourteen three-dimensional ultrasonic anemometers were installed on three floors to stud...

Network

Cited By

Projects

Project (1)