International Journal of

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This paper is an attempt to Numerical Modeling and Experimental Study of Air Flow in the Yazdi Wind-Towers. Wind Towers has been known as one of the most effective climatic elements in Iranian traditional architecture. This paper is an attempt to evaluating Yazdi wind-tower to discussion the two main questions: 1. What is the role of Orientation of wind-towers span, regarding to climate and height of it, in Yazdi wind-tower? 2. How isthe performance of Yazdi wind tower in natural ventilation and air flow in the different seasons of the year? Computer Modeling and Simulation methods and Logical reasoning have been applied in this article, and study of Library Resources was another part of research.Thus, first, the wind-tower has been modeled in computer environment, then after Appling the climatic characterize, final simulation figures and diagrams have been extracted. Results indicate that increasing of the cooling power and optimized efficiency are one of the most important principles of wind-tower design process, and Yazdi wind-towers has mentioned this fact through 4 seasons of the year. By validate computer modeling and simulation, this paper clarify that Iranian traditional ventilation systems has many undiscovered secrets and facts, which need further investigations. This article indicates that natural tactics, which have been applied in the traditional architecture of Iran, can be mentioned as methods to using this valuable heritage in contemporary architecture.

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Wind as an atmospheric element has some annoying aspects, therefore, controlling it and reducing its speed is one of the most important matters, which should be examined in landscape engineering. Natural windbreaks such as rows of trees with different gap distances between them are used to decrease wind velocity. The current study numerically investigates the effect of trees with irregular canopy form on wind speed reduction in urban open spaces and green belts. The computational fluid dynamics (CFD) is used to simulate airflow through the trees as 3D forms. Quercus sp. is chosen as a typical tree with irregular crown shape. The influence of some criteria such as; 1. Number of tree rows, 2. Gaps between trees, 3. Trees arrangement patterns, and 4. Height levels on wind speed reduction are examined at this study.  According to the results, the best reduction is observed for the heights above 5 meters with 0.50 m gap distance between trees. The results also reveal that rectangular two-row arrangement of trees with irregular forms is more effective than the other arrangements in reducing wind velocity.