Analysis and evaluation of the wind effect on user comfort in mass housing open areasanalysis and evaluation of the wind effect on user comfort in mass housing open areas

Today, irregular site planning affects the comfort of pedestrians in public areas. Climatic data in the area are not taken into account during the design process of the buildings. The lack of analysis of climatic data, especially in high building designs, reveals several problems after the construction phase is finished. High-intensity buildings in certain regions create negative wind movements, which affect the comfort of pedestrians in public spaces around the building. For this reason, wind in high building designs is one of the most important factors in terms of pedestrian comfort. Wind tunnel tests carried out in experimental environments to detect the movements of the wind element around the building can not be used continuously in the architectural design process in terms of the cost of the test environment and the length of the test period. With the development of computer technology, the simulation models using the computational fluid dynamics (CFD) method of the wind analyzes have been developed rapidly, the tests which were previously made with high cost experimental environments have been transferred to the computer environments and the experiment process has gained speed. These simulation models have also been used frequently in the architectural design process. But the fact that these analyzes are carried out by the engineers at the end of the project, limits the size of the interventions that can be done to improve the negative areas of wind movements. The interventions are carried out by adding and subtracting the project since the project is completed in mass, and this is not enough to control the wind movements in open areas. In addition, it is observed that these simulation models are not used effectively in practice. Construction activities have accelerated in Istanbul especially after 2000s, and the number of high and intensive mass housing projects has increased. Irregular wind movements that occur in common open spaces in these mass housing projects using different mass forms and layout plans adversely affect pedestrian comfort. In spite of many researches and practices conducted abroad in this field, in Turkey, there are a number of studies on this subject. The aim of this study is to determine the effect of wind movements on the mass settlement alternatives in the first phase of the architectural design process and to determine the methods of the development of settlement plans in line with these data. In computer simulation model environment, wind movements can be generated visually through mass housing settlements and opinions can be created regarding user comfort in open areas. Before the use of such models, the problems experienced due to the lack of time and cost of wind analysis in the first phase of architectural design are now eliminated and the use of these programs in the first phase of architectural design comfortable areas can be created in terms of wind. With simulation models using the Computational Fluid Dynamics method, architects can visually monitor the wind effect in the first phase of design without losing much time, evaluate the settlement options and optimize their designs according to the results. In the first chapter of the thesis, the purpose, scope and method of thesis are explained. The second chapter provides information about the importance of wind effect in design, the effects of wind on buildings and wind protection methods. In the third chapter, the methods used in the evaluation of the wind effect, applications and usage areas of computational fluid dynamics are mentioned. In the fourth chapter, wind analysis and analysis results are given on 6 mass housing projects selected in İstanbul. In the study, models used for wind analysis were researched before the analysis started. These programs are often used for wind analysis; Simscale, OpenFOAM, ANSYS, Comsol and Autodesk CFD etc. In the beginning phase of this study, various programs were tried and it was decided to work with Autodesk CFD program. The reason for choosing this program is that in today's applications Autodesk software is widely used in offices, the program is easily accessible, and it is easy to understand. The study identified mass housing projects in Istanbul with different settlement plans and characteristics. The settlement plans of these mass housing projects were generated with the help of maps and modeled in the 3Ds Max program. When modeling masses, the window, door gap and mass movements less than 3 meters were not added to the model, instead a simple mass model was generated. Since CFD-based analysis programs require high computer capacity. In the similar studies, analyses were made on massive models without adding window and door gaps. The topography is not taken into consideration when modeling. Story height is considered 3.5 meters. Other data required for analysis is wind direction and wind speed. The direction of the wind was accepted as Northeast with the information obtained from the website of the General Directorate of Meteorology. The wind speed is taken from the average wind speed data determined for Istanbul in the weather online website and transferred to the program. Another data that needs to be determined during the analysis phase is turbulence model. The turbulence models provided by CFD programs are generally k-ε models, k-ω models, Reynolds stress model (RSM), Large Eddy simulation (LES) model, Spalart-Allmaras models. Among these models, standard turbulence models provide reasonable solutions to most engineering problems in application. In this study, k-ε turbulence model, which is one of the standard turbulence models from nine turbulence models included in Autodesk CFD program, was used. It was observed that most of the studies investigated in the thesis process use the k-e turbulence model. After all the data were entered into the program, wind analysis was performed vertically and horizontally. In the light of these analyses, the wind movements around the pool, recreational facility and green areas in the settlement were evaluated by considering the user comfort, and comfortable and uncomfortable areas were determined. The height at which wind movements will be studied in the analysis was determined as 1.5 m. The reason for this is that the physical environment of about 1.5 m above the ground has a high impact on human comfort. The effect of other structures around the mass housing area on the wind movement has not been taken into consideration. Since the number of masses in the model increases as the number of analyzes increases. There are not many studies in Turkey in this context. In an existing study, the effect of the building form on wind motion in the plan plane is explained by diagrams; it is not an analysis of climate data and based on general assumptions. However, the simulation models in this study give the results visually and also reflect the wind movements at different levels. In this way, the architect will be able to objectively evaluate the impact of the wind in open areas in terms of user comfort in the early stages of mass housing design and to make decisions about the positions of the masses relative to each other. It is thought that the study will take a pioneering role in considering the wind factor in the housing designs to be carried out in the future.