نوع مقاله : مقالۀ پژوهشی
دکتری معماری، استادیار دانشکده معماری، دانشگاه تربیت دبیر شهید رجایی تهران.
عنوان مقاله [English]
Industrial activities in traditional markets, particularly in hot and humid environments, are conducive to production of aerosols. In addition, thermal stresses resulting from industrial activities can cause disruption of comfort conditions. Dezful has somehow hot and semi-humid climate, hard summers and religious locals. Designers and architects of Dezful try to use natural ventilation in the architecture of buildings. The local religious people, who needed privacy, used different symbols that represent their cultural identity and authenticity in their architecture. Therefore, the Old Bazaar of Dezful was selected for study. The question is how natural ventilation can provide comfort in the semi covered Bazaar of Dezful (industrial passage) under the influence of cultural-religious beliefs of the locals. This study examines the process of natural ventilation in the traditional architecture of the old Bazaar of Dezful, according to the requirements of the local people concerned with identity and religious beliefs. It attempts to provide principles for restoration of the traditional industrial chambers. Regarding the interdisciplinary nature of the study, the research method is an integrated approach: first, using an experimental strategy, the influential independent variables were identified and dependent variables were measured by digital precision devices. Then, case studies were analyzed using the simulation approach. The CFD simulations in this research were performed by Gambit and Fluent software. The program was validated with experimental evidence and simulations. The Fluent software was used to analyze the collected data.A review of the research literature indicates that in the late 1930s and early 1940s there was great interest in the field of Air Engineering. Several standards were imposed around the world in this field. Knowledge of indoor airflow in internal spaces is significant for three reasons: thermal comfort, indoor air quality and energy consumption of the building. In the last two decades, the “Indoor Air Flow” developed in the form of a new field of knowledge. The Old bazaar of Dezful has a linear growth through the urban spaces. The Blacksmith Alley was built next to the main gate of the old city and was later expanded. The most annoying climatic factors are sunlight and moisture. Therefore, the Bazaar’s ceilings must be light and shadow maker. Hot and polluted air must also be expelled from the inner spaces for proper airflow. For this reason, Dezful’s Bazaar has no permanent roof cover. Dezful’s blacksmiths chose some passages with rectangular rooms alongside the road as stores. Four cases were considered for observations and experimental tests and the study focused on two of them. First, a comparison was made between the cases and the symbols of Islamic architecture were studied. A review of the literature reflects the need for proper use of natural ventilation in the industrial stores of the Bazaars called “Hujra”. A questionnaire was developed to study the rate of satisfaction (ventilation, working conditions and status of the architectural workshop) among traditional owners of industrial units. The purpose was finding the main architectural parameters that influence the natural ventilation processes.For a valid study, identification of effective variables is necessary. The validity of the questionnaire was established using SPSS program and by obtaining Cronbach’s alpha. The amount is 0.929 that is higher than the program’s standard (0.873), while the standard alpha should be above 70%. Lutron Machine Model AM-4204 speedometer was used to measure the wind speed. With its hot wire sensor, this device is able to connect to a computer and record the fluctuations of the wind speed in chart track. Meanwhile, the temperature was recorded by the machine’s sensor. Because of the technical specifications of the device, velocities less than 0.2 m/s are not measurable. Therefore, computer simulation for elaboration of the observations and reducing errors was indispensable. In this study, the pre-processor “Gambit” was used to make the geometric modeling and the meshes. Then, the Fluent software was used to analyze the geometric models and meshes. With the help of experimental methods, the validity of the program was established. In order to find the dominant wind direction, the smoke test was performed during observations in the Bazaar. Experimental observations showed that the dominant wind direction is from southwest to northeast throughout the year (from the quibla). So the orientation of the buildings in the city guides the airflow in the passages and the bazaar, and facilitates natural ventilation in Dezful’s alleys. The final results showed that the indoor air flow (dependent variable) can be influenced by building orientation, Islamic architecture’s symbols, composition and location of outlets and openings (independent variables). The simulations also showed that there is always a constant airflow in the bazaar regardless of the condition. Thus, the cultural identity of the indigenous people in the Old Bazaar does its best to collaborate with the engineering and the technology of the era to establish comfort conditions and improve natural ventilation in the form of a unique architecture style.