Outdoor Wind Environment Research Articles

Evaluation of the influence of traditional village square layout factors on wind comfort

The layout factors of traditional village squares play a significant role in determining the comfortable outdoor wind environment, making them the primary venue for outdoor communication activities among residents. This study focuses on the traditional village square spaces within the jurisdiction of Quanzhou City, Fujian Province, China. Through onsite measurements and CFD simulations, the effects of various layout factors on the wind environment are compared and analyzed. The results are as follows: (1) The plane permeability index of the enclosed square space layout impacts wind speed, comfort, and ventilation performance. Lowering the index will decrease wind speed, but it will improve comfort. (2) Increasing the height-to-cross-section ratio index of the enclosed layout of the square space will reduce wind speed, thereby improving wind comfort. (3) Increasing the enclosure rate index of the square space enclosure layout will decrease wind speed, resulting in better wind comfort. Overall, the research findings indicate that careful consideration should be given to the enclosed layout of traditional village square spaces to ensure optimal wind conditions.

A Numerical Simulation-Based Adaptation of the Pedestrian-Level Wind Environment in Village Streets: A Case Study on the Chuan Dao Area of the Hanjiang River in Southern Shaanxi

Village streets are indispensable spaces for people to perform outdoor activities, and they also directly affect the outdoor wind environment in villages. At present, people are paying more attention to the wind environment comfort of urban residential areas and urban commercial streets, but there is a lack of attention and research on the wind environment comfort of village and town streets. By summarizing the field research and meteorological data of Lefeng Village, we propose the outdoor wind environment evaluation requirements applicable to the Hanjiang River’s Chuan Dao area in the winter and summer seasons. We found that more than 80% of the outdoor wind environment in the summer is less than 1 m/s. Based on the numerical simulation method of computational fluid dynamics, and on the basis of the characteristics of the streets and lanes in the Hanjiang River’s Chuan Dao area, we found that the wind environment is poor in the winter and summer seasons; regarding streets and lanes, we propose three appropriate values, namely building density, building height, and street width. It is suggested that it is appropriate for the building density of the area to be less than 36%, the height of the building to be less than 15 m, and the width of the street to be 6–11 m when the street is open to traffic and 3–6 m when only pedestrians are passing through the area.

Optimization Study of Outdoor Activity Space Wind Environment in Residential Areas Based on Spatial Syntax and Computational Fluid Dynamics Simulation

In the context of increasing global energy shortages and climate change, the human living environment, as a crucial component of residents’ daily lives, has garnered growing attention from the academic community. Research on residential environments is vital for promoting the sustainable development of urban construction and constitutes an important aspect of sustainable development studies. This study focuses on the optimization strategy for the outdoor activity space wind environment in the Xihuayuan residential area in Lanzhou city, utilizing spatial syntax analysis and Computational Fluid Dynamics (CFD) simulation technology. Firstly, the outdoor activity space is analyzed for visibility and spatial accessibility using DepthmapX0.6 software. Then, the outdoor wind environment in the residential area is simulated using PHOENICS 2018 software, and the analysis is conducted on outdoor spaces with a poor wind environment in terms of high accessibility. The results indicate that residents’ outdoor comfort in these spaces is poor, highlighting the urgent need for improvement in the wind environment. This research attempts to optimize the wind environment in high-accessibility spaces within the residential area by improving building layout, orientation, and height. The simulation results after optimization demonstrate an increase in the overall average wind speed to 1.44 m/s, with the proportion of spaces with a good wind environment in high-accessibility areas during summer rising from 33.4% to 59.2%. The optimization strategy effectively improves the wind environment in high-accessibility areas of the residential area.

Machine Learning for Real-Time Building Outdoor Wind Environment Prediction Framework in Preliminary Design: Taking Xinjiekou Area of Nanjing, China as the Case

The incorporation of physical environmental performance as a primary consideration in building design can facilitate the harmonization of the built environment with the surrounding site and climate, enhance the building’s environmental adaptability and environmental friendliness, and contribute to the achievement of energy-saving and emission-reduction objectives through the integration of natural lighting and ventilation. General computational fluid dynamics (CFD) can help architects make accurate predictions and effectively control the building’s wind environment. However, CFD integration into the design workflow in the preliminary stages is frequently challenging due to program uncertainty, intricate parameter settings, and substantial computational expenses. This study offers a methodology and framework based on machine learning to overcome the complexity and computational cost barriers in simulating outdoor wind environments of buildings. In this framework, the machine learning model is trained using an automated CFD simulation system based on Butterfly and implemented within the Rhino and Grasshopper environment. This framework provides real-time simulation feedback within the design software and exhibits promising accuracy, with a Structural Similarity Index Measure (SSIM) ranging from 90–97% on a training dataset of 1200 unique urban geometries in Xinjiekou Area of Nanjing, China. Furthermore, we programmatically integrate various parts of the simulation and computation process to automate multiscenario CFD simulations and computations. This automation saves a significant amount of time in producing machine-learning training sets. Finally, we demonstrate the effectiveness and accuracy of the proposed working framework in the design process through a case study. Although our approach cannot replace CFD simulation computation in the later design stages, it can support architects in making design decisions in the preliminary stages with minimal effort and immediate performance feedback.

Natural ventilation potential of teaching building complexes with different block shapes and layout patterns

Natural ventilation significantly enhances building energy efficiency and indoor air quality, thereby reducing virus transmission risks, especially crucial in teaching buildings on university campuses frequently occupied by large numbers of students. This study investigates the design impacts of teaching building complexes on indoor and outdoor wind environments, aiming to propose practical design recommendations. Firstly, a typological analysis of teaching building complexes from ten universities in Guangzhou University Town (GUT) was conducted, screening out several archetypes representing diverse design features. Computational fluid dynamics (CFD) simulations were then performed on 16 hypothetical teaching building complexes derived from these archetypes. The wind velocity distributions and area-weighted wind velocities across various hypothetical scenarios were compared and analyzed, allowing for a thorough assessment of the natural ventilation performance associated with different block shapes and layout patterns. The findings reveal that canyons between buildings have a marginal impact on natural ventilation within scenarios characterized by aligned layouts. In contrast, staggered layouts notably enhance natural ventilation, particularly with orthogonal prevailing winds. Furthermore, semi-enclosed courtyard blocks outperform fully enclosed courtyard blocks in natural ventilation, especially when their openings align with prevailing wind directions. Finally, several practical recommendations were summarized for achieving sustainable teaching building design in similar climate regions. Key contributions include demonstrating the significant influence of block shape and layout on ventilation performance and offering novel insights into optimizing building designs for improved natural ventilation.

Study on the Impact of Design Factors of Piloti Forms on the Thermal Environment in Residential Quarters

Study on the Impact of Design Factors of Piloti Forms on the Thermal Environment in Residential Quarters

Evaluation and optimization of outdoor wind environment in block based on space syntax and CFD simulation.

The wind environment quality at the height of pedestrians can significantly affect the thermal comfort and physical and mental health of pedestrians, promote the diffusion of air pollutants and inhibit the formation of urban heat island effect, and has been paid more and more attention in the field of urban and rural planning. This paper takes Jianlan Road commercial pedestrian Street as an example to maximize the thermal comfort of pedestrians. Based on CFD numerical simulation technology and space syntax theory, the pedestrian wind environment of the accessible space of the block is selected for quantitative research. Through numerical simulation, the influence of block spatial form on the wind environment at pedestrian height under the initial condition of uniform air flow is analyzed, and some suggestions are put forward for the optimization of block spatial form. Finally, the block optimization scheme is verified and simulated. The visualization results show that the wind environment quality of the optimized high-accessibility space is significantly improved, the proportion of comfort zone is increased from 58.2% to 86%, and the static wind rate is reduced from 41.8% to 14%. The wind environment optimization effect is obvious.

A Wind Protection Design Strategy for Airport Terminal Door Bucket Space Based on Wind Environment Simulations

Airport terminal buildings are large public transportation buildings with complex functions and dense crowds, and the wind environment has significant effects on passenger comfort and the energy consumption of air conditioning systems. In this study, we investigated Xianyang T3 Terminal as an example and used the Phoenics software to conduct comprehensive simulations based on different door bucket forms and parameters, as well as comprehensively considering the impacts of different outdoor wind environments. A terminal door bucket windproof design strategy was proposed based on our results. The results showed that door buckets could effectively reduce the entry of outdoor wind, and built-in door buckets performed the best. The width of the door bucket should be set to 9.3–11.3 m and the depth of the door bucket to 6.7–7.7 m. The height of the door bucket had little impact. A side door should be added to the door bucket, so it can be opened when the outdoor wind speed is high, and a mechanical ventilation system should be introduced to improve the indoor ventilation.

Research on the wind environment in an enclosed courtyard: Effect of the opening position, size and wind angle

With the urbanization process in China, outdoor thermal environments are drawing increasing attention, of which comfortable pedestrian height wind environments are crucial for urban outdoor spaces. Few studies have been conducted on the comfort wind zone ratio (CWZR)11Abbreviations: CFD, computational fluid dynamics; CWZR, comfort wind zone ratio; MWSR, mean wind speed ratio; SWZR, static wind zone ratio. models for openings in enclosed courtyards. We quantitatively analyzed the effects of different opening positions, sizes, and wind angles on the wind environment of campus enclosed courtyards via computational fluid dynamics (CFD) simulations, and CWZR models were established for different opening sizes and wind angles. The results are as follows: (1) The opening position, opening size and wind angle significantly affected the outdoor wind environment. (2) Under the dominant wind direction in summer, the cross-opening position better improved the courtyard wind environment than the symmetrical opening. The courtyard CWZR significantly increased with increasing inlet opening size and increased with decreasing outlet opening size. (3) A wind angle from 2° to 47° is the recommended angle for typical courtyard opening types, and the maximum courtyard CWZR occurred at a wind angle of 10°. The study results could guide courtyard building design and courtyard wind environment optimization and enrich the theoretical study of outdoor wind environments.

WIND ENVIRONMENT ANALYSIS OF GREEN BUILDING BASED ON BUILDING INFORMATION MODELING (BIM)

ABSTRACT This papers offers a more simple and effective method to simulate indoor and outdoor wind field at the same time, while also exploring the influence of indoor wind field on air conditioning energy consumption. This paper presents an application framework for simulating indoor and outdoor wind field and an air conditioning system based on BIM. Through the BIM software with built-in CFD calculation, the indoor and outdoor wind environment is simulated, and it is found that the outdoor vertical wind field has a certain influence on indoor ventilation. Meanwhile, the air conditioning energy consumption of the building is calculated, and the influence of indoor natural ventilation on air conditioning energy consumption is quantified. This paper provides important guidance for building researchers and practitioners to better align BIM development with green building development in the future.

Simulation Study on Outdoor Wind Environment of Residential Complexes in Hot-Summer and Cold-Winter Climate Zones Based on Entropy-Based TOPSIS Method

Driven by a large digital simulation environment, CFD calculation software is used to simulate test results so that they can be effectively applied to engineering practice. This paper explores the suitable outdoor wind environment for residential areas in the hot summer and the cold winter. Taking Xishan Huijing in Changsha as an example, the most unfavorable wind field environment is used as the boundary condition, and the optimal design mode for this residential area is explored based on the Butterfly platform. The research in this paper is mainly divided into five steps: (1) using Rhino 7.0 to establish a 3D model; (2) using the Butterfly 0.0.05 platform to simulate the wind field and export the data at the same time, and to realize the preview through the visualization method; (3) processing the exported simulation data and the calculation of related indices; (4) applying the entropy-based TOPSIS method on the MATLAB 2020 platform to rank the preferred scheme and obtain the corresponding index weights; and (5) using a K-means cluster analysis on SPSS 26 software to optimize the scheme. The results show that (1) the wind environment quality will be overestimated in the summer if the influence of neighboring buildings on the site is not considered, while the opposite is true in the winter, with the error of both reaching two times. (2) The weights of the indicators determined by the TOPSIS entropy weighting method indicate that wind protection in the winter should be prioritized over natural ventilation in the summer in this area. The maximum wind speed in the winter has the most significant weight, reaching 0.287, and the uniformity of the wind field in the summer is the most important, reaching 0.1102. (3) In the layout design of the residential district, the staggered layout of the 60 m high slab houses in the northern, northeastern, and northwestern directions of the site creates a better wind field environment, which attains the highest score by the TOPSIS entropy weighting method, reaching 0.1539, with the second highest score, reaching 0.1511, for the layout method. The research results will provide a scientific basis for the design of residential buildings in the hot-summer and cold-winter regions in China, and also help designers to better grasp the outdoor wind environment of residential buildings in the pre-design stage.

Research on the Influence Mechanism of Outdoor Wind Environment on Indoor Smoke Exhaust Efficiency in the Super-High-Rise Tower Crown Based on Airpak Simulation

The high wind pressure and velocity of the outdoor environment make super-high-rise tower crown space distinct from general tall through space. This segregation causes the crown space to be particularly prone to smoke short-circuiting influenced by the outside wind environment if a fire occurs indoors, and causes deficient smoke exhaust efficiency in a fire. The goal of this study was to investigate the general principle regarding the effect of the outdoor wind environment on smoke exhaust efficiency of such spaces under the crown space. We measured external wind direction and wind pressure in the smoke exhaust in the tower crown and developed setting plans for the exhaust outlets and make-up air inlet. Airpak was used to create the external wind environment and compare simulations to see if smoke short-circuiting occurred. We analyzed the causes, summarized solutions that did not result in short-circuiting of smoke flow, and made adjustments. We provide an ideal plan for the setting direction and vent velocity of the make-up air inlet and exhaust outlet in the crown spaces of super-tall towers to improve the design of smoke exhaust systems in such spaces.

Influence of outdoor meteorological parameters on the indoor environment of blast furnace yard.

The blast furnace tapping yard is a typical heavy-pollution industrial plant. Aiming at the problem of high temperature and high dust, the CFD model is established to simulate the coupling of indoor and outdoor wind environment, field measurement data are used to verify the simulation model, and then, the influence of outdoor meteorological parameters on the flow field and smoke emission of blast furnace discharge field is studied. The research results show that the impact of the outdoor wind environment on the air temperature, velocity, and PM2.5 concentration field in the workshop cannot be ignored, and the influence on dust removal in the blast furnace is significant. When the outdoor velocity increases or the temperature decreases, the ventilation volume in the workshop increases exponentially, the capture efficiency of PM2.5 by the dust cover gradually decreases, and the PM2.5 concentration in the working area gradually increases. The outdoor wind direction has the most significant influence on the ventilation volume of industrial plants and the capture rate of PM2.5 by a dust cover. For factories facing north from south, the southeast wind is an unfavorable wind direction with a small ventilation volume, and the concentration of PM2.5 in the area where workers are active exceeds 2.5mg/m3. The concentration of the working area is affected by the dust removal hood and the outdoor wind environment. Therefore, outdoor meteorological conditions under the dominant wind direction in different seasons should be considered when designing the dust removal hood.

Study on Skywell Shape in Huizhou Traditional Architecture Based on Outdoor Wind Environment Simulation

This study was conducted in the context of the latest Chinese policy on “double carbon”. First, we obtained building skywell and meteorological data parameters through a site survey and measurements. We applied the PHOENICS software to simulate and analyze the wind environment of a traditional building skywell. Secondly, the outdoor wind environment of typical building skywells could be simulated and evaluated one by one. Finally, using the method of controlling the variables and by combining typical buildings and skywell-scale layouts, the study summarized and compared the wind environment of the skywell under different scale combinations from three aspects: building skywell shape, skywell scale ratio, and skywell door opening. The following conclusions were drawn: (1) Among the four skywell shapes, the wind environment inside of the skywell was best in the HUI shape. (2) The wind environment inside of the skywell was best in the simulated skywell width-to-height ratio D/H values of 0.2–0.6; the AO shape D/H value was equal to 0.3; and the best wind environment in the skywell occurred when the D/H value of the HUI shape was equal to 0.4. (3) The wind environment in the skywell was best in the range of 1–1.5 for the aspect ratio W/L in the HUI-shaped building skywell (when the width-to-height D/H ratio was 0.4). (4) The opening of the door of the residential building had a great impact on the wind environment of the skywell.

The Coupling Relationship between Building Morphology and Outdoor Wind Environment in the High-Rise Dormitory Area in China

A good outdoor wind environment can guarantee the safety and comfort of student activities. It is also conducive to building energy-saving and low-carbon goals. In this study, the high-rise dormitory area of a university was selected as a research object in the cold region. The study used a combination of numerical simulation and orthogonal tests to analyze the weighting of the influencing factors of the wind environment and to recommend the optimal design scheme. The results indicated that the building layout, building length, width, and height all had different degrees of influence on the outdoor wind environment of the dormitory area. For the slab-type high-rise dormitory, the influence weight of the layout was the strongest, followed by the building height, the width, and, finally, the length. The optimal scheme is a staggered layout with a building length of 50 m, width of 18 m, and height of 85.2 m. The wind environment in this situation performed well in winter and summer. For the tower-type high-rise dormitory, the influence weight of the building height was the greatest, followed by the width, the length, and then the layout. The optimal scheme is a staggered layout with a building length of 26 m, width of 24 m, and height of 85.2 m. The wind environment in this situation performed well. Overall, the study scrutinized the coupling relationship between building morphology and wind environment from the meso-level perspective. At the micro level, we constructed the design method for the dormitory building morphology by considering the wind environment performance as the target. It can assist designers in making decisions during the planning and design phases of project construction to facilitate the positive design of buildings.

Influence of Piloti Forms on Wind Comfort of Different Building Group Layouts by Large Eddy Simulation

This paper studies the influence of different piloti rates (0%, 20%, 40%, 60%, 80%, 100%) on outdoor wind comfort for three building groups, i.e., determinant type, point type, and enclosure type. LES (Large Eddy Simulation) is used to simulate the wind environment of three clusters at six different piloti rates. This paper mainly studies the effect of piloti rate on wind speed at pedestrian level (1.5 m). The outdoor wind environment was analyzed using the average wind speed ratio, and outdoor wind comfort was evaluated using the comfortable wind ratio. The following results were obtained: (1) The piloti setting has little influence on the overall wind speed in the target area, and even an inappropriate piloti rate setting may reduce the overall average wind speed in the target area. (2) A comprehensive comparison of the three building layouts shows that the comfortable wind ratio of the determinant layout is the highest when the piloti ratio is 80%. The results of this study can provide architects and urban planners with reference for piloti and urban layout settings.

A Simulation Study of the Outdoor Wind Environment of Low Carbon Buildings in Cold Regions Based on PHOENICS Software

Based on PHOENICS software, the suitability of the outdoor wind environment at pedestrian heights of a low-carbon building under different operating conditions was quantitatively analysed using a κ-ε numerical model of low-speed turbulence. Three simulated conditions for the outdoor wind environment of low carbon buildings were determined by typical annual meteorological parameters for Shijiazhuang in cold regions. Combining the information on the full domain flow field obtained from the numerical simulations, the appropriate wind environment parameters were determined. The analysis of the wind environment indicators revealed that the low carbon buildings studied had clear year-round wind flow lines, with no dead zones and no obvious vortex areas. The wind speed at the pedestrian height of the low carbon building under different working conditions was less than 5 m/s (Wind speed in winter, summer and transitional season were 2.95 m/s, 2.54 m/s, and 3.3 m/s respectively), which meets the requirements of human comfort and standard regulations. The surface pressure difference between the different operating conditions (winter, summer and transitional seasons) of the low carbon building is not higher than 5 Pa, which meets the requirements for wind protection in winter in the area and contributes to the comfort level required for ventilation in summer. The study of the building wind environment can effectively identify the gap between the design and the actual use process, providing effective reference and guidance for the actual construction.

Coupled simulation of CFD and human thermoregulation model in outdoor wind environment

Understanding of dynamic and transient wind environment is crucial to evaluating the outdoor thermal comfort of pedestrians. The thermophysiological responses of the human body depend on both the interaction with the climate and internal thermoregulation. The coupled simulation of CFD and thermoregulation model provides a pathway to predict human responses under non-uniform conditions where local effects may dominate thermal comfort. In this work, we explore the potential of coupled simulation under outdoor environmental conditions. The thermoregulation model JOS-3, which consists of 85 nodes and 17 body segments, is used to simulate the physiological responses and the obtained mean skin temperature is fed into CFD as the boundary condition of the thermal manikin. The thermal interactions between the human and surrounding environment in the wind tunnel, represented by convective and radiant heat transfer coefficient, are calculated by CFD and serve as inputs for the JOS-3 thermoregulation model. The results exhibit that under the wind velocity of 1 m/s and turbulent intensity of 11.6%, the coupling can converge within two iterations. This is because the convective heat transfer coefficient is not significantly affected by the body skin temperature under the assigned outdoor airflow velocity, which is higher than the value in an indoor environment. The study demonstrates the workflow of coupled simulation in an outdoor wind environment and could be a useful tool for evaluating outdoor thermal comfort under different conditions in the future.

Accessibility Study of a Compact Wind Tunnel with an Unequal Spacing Grid for the Outdoor Wind Environment

One of the key issues in architectural design and regional planning is to create a safe and comfortable outdoor building environment, which calls for more studies. Wind tunnel experiments and computational fluid dynamic (CFD) simulations are the primary methods for the current studies. The airflow and boundary conditions are controllable for the wind tunnel experiment, and the data is reliable. In most wind tunnel platforms, spires and roughness elements are applied to create the gradient wind of the atmospheric boundary layer, leading to the oversized, high construction cost, and complex operation. In this paper, in order to explore a simple method for measuring and studying the outdoor building wind environment using wind tunnels, a compact wind tunnel platform adopting grids with unequal spacing was designed and tested, based on the theoretical model of the atmospheric boundary layer. A comparison between the test results and the theoretical values indicated that this new wind tunnel platform could achieve a gradient wind field and is accessible in applying low-speed wind tunnels to the measurement and research of the building wind environment. The application case in a high-rise building of the central business district (CBD) region in Beijing, was presented in this paper. Compared with another analytical method, the CFD simulation, the compact wind tunnel revealed its applicability that could be used for predicting and evaluating the outdoor wind environment around the building. This compact wind tunnel is more flexible and convenient than the traditional ones, with a smaller size, easier construction and operation, and lower costs. Therefore, we suggest more applications of this compact wind tunnel platform in future experimental studies of outdoor wind environments.

An Experimental and Numerical Study of the Winter Outdoor Wind Environment in High-Rise Residential Complexes in a Coastal City in Northern China

In recent years, residents in high-rise residential complexes (HRCs) in China have been placing an increasing demand on the living quality in HRCs. Particularly, the outdoor wind conditions are garnering more attention; however, few studies on the wind conditions within HRCs with densely arranged buildings and high plot ratios have been reported. Therefore, this study investigated the relation between the buildings’ layouts in HRCs and their wind conditions and it proposes optimization strategies to enhance body comfort in their outdoor environments. The research methods in this work involved field surveys, computational fluid dynamics (CFD) simulations, and field monitoring. The field surveys were used to determine the types of activities undertaken by the residents in the selected HRCs and their perceptions of the wind conditions within the HRCs. Field monitoring was primarily conducted to measure the present wind conditions in the HRCs. The CFD simulations were performed to analyze the interactions between individual buildings and the wind as well as the performance of the wind conditions in the HRCs before and after a building layout optimization. The simulation results and monitoring data showed that the present wind conditions in the HRCs were uncomfortable due to high wind speeds (exceeding 5 m/s) and large windless areas. To achieve a comfortable outdoor wind environment, future HRCs should adopt a point-to-point building layout and the buildings should be oriented south. Moreover, the ratios of the height to width (Hb/Wb) for individual buildings should be kept at approximately 1.33. For existing HRCs, landscape walls, trees, and moveable windbreak panels can be used to reduce the wind speeds, especially in open exit/entrance areas and windward areas.