نوع مقاله : مقاله پژوهشی

نویسندگان

1 کارشناسی ارشد طراحی شهری، دانشگاه آزاد اسلامی واحد نایین، اصفهان، ایران.

2 دکتری شهرسازی-پژوهشگر حوزه ریخت شناسی و طراحی پایدار شهری

چکیده

توسعه انرژی باد در محیط­های ساخته شده موضوعی قدیمی برای ساکنان پایدار شهر است که با افزایش فناوری­های جدید توجه بسیاری از محققان را به خود جلب کرده است. در این مقاله سعی شده، پتانسیل انرژی بادی شهری با استفاده از تحقیقات بر روی مورفولوژی شهری مورد تجزیه و تحلیل قرار گیرد. در این مطالعه اطلاعات باد از ایستگاه هواشناسی اصفهان در میانگین گرمترین روز (30تیرماه) و سردترین روز (30دی ماه) در سال 1396 برای انجام مطالعات شبیه­سازی عددی در سه پیکره­بندی شهری (سنتی، شطرنجی و بلندمرتبه گسسته) در مقیاس محلی که معرف شاکله کلی از ریخت گونه شهر اصفهان هستند، با استفاده از نرم‌افزارهایEnvi-met and Design Builder برای تجسم نتیجه انرژی باد شبیه­سازی می­شوند. در نهایت سه بافت مختلف شهری با چندین پارامتر مربوط به مورفولوژی شهری و محیط باد مقایسه و تحلیل شد. نتایج نشان می­داد که 1)بافت­های سنتی براساس شبیه­سازی عددی سرعت و جهت باد و همچنین تحلیل­های کلی بر روی هندسه بافت از نظر شاخص­های مورفولوژیک تأثیرگذار نشان از طراحی کاملاً منطبق براساس اصول پایداری است و این که ﭼﮕﻮﻧﻪ شهرسازان و ﻣﻌﻤﺎران ﺑﺎ به ‌کارگیری اﺻﻮل ﺻﺤﻴﺢ مورفولوژی شهری می‌توانند در بهینه‌سازی ﻣﺼﺮف اﻧﺮژی و بهره­وری درست از جریانات باد شهری مؤثر واﻗﻊ ﮔﺮدﻧﺪ، 2)نتایج شبیه­سازی عددی سرعت و جهت باد در بافت شطرنجی و بلندمرتبه گسسته نشان داد که شهرسازی مدرن کمتر هماهنگ و همساز با اوضاع محیط طبیعی ازجمله شرایط اقلیمی و فرهنگ بومی رشد و توسعه پیدا کرده است، 3)شاخص­های مورفولوژیکی شهری با شاخص بالقوه جریانات باد همبستگی معنی­داری دارند و به کمک این شاخص­های مورفولوژیکی می­توانیم به طور دقیق، خروجی جریانات انرژی باد بر روی بافت­های مختلف شهری باتوجه به رویکرد انرژی کارا را مقایسه کنیم و 4)در نهایت نتایج این مطالعه به عنوان یک راهنمای عملی برای ارزیابی تأثیرات جریانات باد شهری و اثرات متقابل آن بر روی مورفولوژی شهری و روش‌های پیشنهادی در این پژوهش به عنوان تحلیل‌های حداکثری برای اقدامات کاربردی به‌منظور کاهش اثرات منفی جریان باد برای مدیریت شهری در شهر اصفهان را به ارمغان می­آورد.

کلیدواژه‌ها

موضوعات

عنوان مقاله [English]

The Effect of Traditional and Modern Urban Morphology Patterns on Wind Flow and its Interactions with the Energy Efficiency Approach (Case Study: Esfahan)

نویسندگان [English]

  • Zahra Babaei frooshani 1
  • Yones Changalvaiee 2

1 Master of Urban Design, Islamic Azad University, Nayin Branch, Isfahan, Iran.

2 PhD in Urban Planning - researcher in the field of morphology and sustainable urban design

چکیده [English]

Highlights
Evaluation and comparison of key indicators of wind energy flows and their evaluation in the sustainability of urban morphology.
Investigation of wind flow in three real urban patterns that represent the three general morphologies of the city of Isfahan.
Numerical simulations were performed to visualize the steady state of three real urban patterns.
Several urban morphological indices were found with high correlation with wind energy indices.
Intervention and development strategies to reduce the negative effects of wind flow for urban management of Isfahan.
 
Introduction
The development of wind energy in built environments is an old topic concerning sustainable urban residents, which has appealed to many researchers with the enhancement of new technologies and CFD techniques. This work seeks to study wind energy flows from the perspective of urban morphology.
Methodology
In this research, the average numerical wind data have been collected from Isfahan meteorological station on the hottest day (21 July 2017) and the coldest day (20 January 2018) in the corresponding Iranian year for CFD studies on wind distribution in three urban configurations (traditional, gridded, and high-rise buildings) in local scale, which represents the overall structure of the morphological types in the city of Isfahan, Iran. The CFD have been numerically simulated and illustrated in the ENVI-met and DesignBuilder software to visualize the wind energy results obtained from each urban fabric.
Results and Discussion
The simulation results demonstrate the following. 1) The results for the traditional fabric based on the maximum value of wind speed and direction obtained from the software include 2.26 m/s on the hottest day and 2.68 on the coldest, lying in the category of gentle breeze based on the Beaufort scale. In terms of the comfort zone for activities such as sitting, standing, and walking, this does not cause problems for citizens, and the texture lies in the comfort zone. 2) The results involving the maximum value of wind speed and direction in the gridded fabric include 2.73 m/s on the hottest day and 2.80 on the coldest. For high-rise buildings, maximum wind speed is 4.26 m/s on the hottest day and 4.08 on the coldest. On the basis of the Beaufort scale, therefore, gridded and high-rise buildings lie in the medium breeze category. Moreover, the comfort zone for the sitting and standing activities in the gridded fabric is not a problem for citizens, but makes them feel a little uncomfortable with the walking activity. For high-rise buildings, however, there are many problems, and citizens feel plenty of discomfort based on the comfort range for the sitting, standing, and walking activities. 3) The results obtained from the study of the two pieces of software demonstrate that the power and accuracy of the numerical simulation made by ENVI-met is greater than that of DesignBuilder due to the focus and design of the former software in the field of urban planning, providing researchers with more accurate documentation.
Conclusion
The results of the analysis are as follows. 1) The traditional fabric has been designed entirely based on the principles of sustainability. The urban morphological parameters indicate the important role that urban architects and designers can play in optimal energy consumption with respect to wind flow by determining the morphological parametric criteria. 2) The overall analyses of the geometry of the two new fabrics (gridded and high-rise buildings) demonstrate that modern urban planning is in less accordance with the natural environment, including climatic conditions and indigenous culture. 3) The large differences between the three fabrics in terms of the different characteristics of urban morphology and the different effects of wind energy flow indicate the significant effect of urban morphology on potential wind flows, showing that the urban morphological indicators are significantly correlated with wind flow. 4) The results can be used as a practical guide for evaluation of the effects of urban wind flows and their interaction with urban morphology. The methods proposed in this study can be used as maximal analyses made for practical measures taken to reduce the negative effects of wind flow for urban management in Isfahan. Future extensions of this study, which is currently under investigation, will be aimed at a comprehensive examination of all climatic factors affecting urban morphology and, finally, achievement of an optimal, sustainable model for Isfahan and all climates in Iran along with the factors examined in this research.

کلیدواژه‌ها [English]

  • Traditional and Modern Urban Morphology
  • Wind Flow
  • Energy efficiency
  • numerical simulation
  • CFD
  • Isfahan
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