Climate comparative building energy optimization: a retrofit approach including solar photovoltaic panels and natural ventilation

Given the importance of optimal consumption of energy in buildings, as one of the major energy consumption parts, a real residential villa was simulated in the hot and dry and also hot and humid climates in this study. The solar irradiation of photovoltaic panels was used for partial supply of energy needs of the building. The proposed strategies to improve the building and reduce its energy consumption included thermal insulators embedded in the walls and the ceiling, and replacement of simple old windows with double glazed windows equipped with temperature sensors and smart interior shadings. In hot and dry climate of Isfahan, implementing solar panels, wall and ceiling insulation, double glazed smart windows, internal smart shading and natural ventilation lead to optimal energy consumption with 38.43 and 50.94% reduction in the cooling and heating loads, respectively. In hot and humid climate of Bandar Abbas, all of mentioned scenarios except natural ventilation were used and showed 46% thermal loads reduction. Solar power could support 67.3% of electricity in Isfahan and 42.3% of it in Bandar Abba

The Effect of Drag Force on The Body Frequencies and The Power Spectrum of a Bladeless Wind Turbine

The new types of bladeless wind turbines and generating electricity using them is one of the most interesting topics for engineering nowadays. Electricity generation using the structural vibration due the resonance phenomenon is the concept behind a vortex bladeless turbine. The present study numerically investigates the effects of the drag force on the body frequency of an oscillating bladeless wind turbine. A 2-D numerical simulation was performed for a cylinder with a semi-circular cross-section in cross-flow in two different cases. The research was conducted for both uncontrolled and controlled oscillating cylinders. The controlling process was performed using a pair of ring magnets as a spring with a variable coefficient. The flow field, vibration, vortex shedding and structural frequencies, and the resonance phenomenon are studied in this research. Finally, the controlled and uncontrolled frequencies of the cylinder are explored, and the power spectrum for various velocities is analyzed in two different states, namely with and without a tuning system. From the results, it can be concluded that the usage of the controlling system in these turbines can greatly regulate the oscillations and increase the frequency value by limiting the vibration amplitude. According to this principle, it can be inferred that increasing the frequency of fluctuations greatly increases the production capacity of these turbines.The accepted manuscript in pdf format is listed with the files at the bottom of this page. The presentation of the authors' names and (or) special characters in the title of the manuscript may differ slightly between what is listed on this page and what is listed in the pdf file of the accepted manuscript; that in the pdf file of the accepted manuscript is what was submitted by the author