The Impact of External Shading Design on the Building Energy Consumption
In this paper, the effect of an exterior shading element (Iwan) on energy consumption in four different climatic regions, and for different geographical directions, has been investigated numerically and experimentally. By applying different materials and techniques and creating various elements and spaces, architects make hard climatic conditions more tolerable for residents. Iwan is one of the cooling elements which is used in different forms and dimensions in the Islamic architecture. In the present research, Iwan has been introduced as a climatic element in traditional and contemporary architectures and its role in reducing the energy consumption in buildings has ben studied. In this respect, first, the thermal loads of a building without Iwan are computed by means of EnergyPlus software. Then, four different forms of Iwan are added to the abovementioned structure along the four principal geographical directions, and the effect of Iwan on the reduction of thermal loads is analyzed for four different climates. Finally, the design parameters of Iwan, in terms of depth and form, that can help reduce the thermal loads in different climatic conditions are presented. The results show that the best position for using an Iwan is the south direction and the use of Iwan in temperate & humid, hot & humid, cold & mountainous and hot & dry climates could reduce the energy consumption in buildings by 32%, 26%, 14%, and 29%, respectively.
An experimental and numerical investigation of Shovadan heating and cooling operation
Abstract Shovadan is the underground room which, for a long time, has been used in several areas of Iran for heating and cooling purposes. In the present work, Shovadan heating and cooling performance is experimentally investigated during a year. In the sample studied, when the ambient temperature is 7 °C in January and 47 °C in July, Shovadan average temperature is 17 °C and 23 °C, respectively. The suitable Shovadan temperature range proves the ability of this space in architecture optimization for saving energy. Next, in order to save time and cost to study more Shovadans in other locations, a three-dimensional model is simulated in real size. Then, Navier–Stokes and energy equations have been numerically solved and the temperature distribution within a Shovadan has been calculated. Numerical results are in good agreement with the experimental data. Finally, ventilation effectiveness was evaluated in the coldest and warmest months.
Mechanics of deformable directed surfaces
Abstract The paper develops a simple, yet complete and consistent non-linear dynamic thermo-elastic shell theory based on the concepts of a two-dimensional directed continuum. The constitutive equations are postulated in a general form. Stress-strain relations are derived using the equation of energy balance and the two entropy production inequalities, which are rewritten in a special form. The linear theory is discussed in detail. The structure of the stress-strain relations is presented in the most general form and then specialized to concrete examples, in particular, to the classical shell theory, using their invariance properties with respective to certain symmetry groups. The elastic moduli are determined by demanding the coincidence of the frequency dispersion surfaces obtained using the two-dimensional theory with the lowest foils of the corresponding surfaces resulting from the three-dimensional theory of elasticity.