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Energy harvesting from wind in urban areas is an important solution to meet energy needs and environmental care. This study describes the effect of blade angle on the aerodynamic performance of small-scale Archimedes spiral-wind-turbine blades by computational simulation, which is experimentally validated. Archimedes wind turbine is classified as one of the HAWTs. The computational approach was used to predict the aerodynamic performance of the scaled-down rotor blades. Blade angle is defined by the angle between the rotational axis and the tip of the blade, which varied from 50° to 65° with an interval of 5°. The computational study was carried out using the ANSYS CFX 19 software for a steady incompressible flow. The performance parameters of the wind turbine, which are power and torque coefficients were explored for different blade angles. This was carried out for wind speed from 5 to 12 m/s with an interval of 1 m/s. In order to validate the results of the computational simulation, an experimental study was carried out using a scaled-down 3D-printed models. The experimental study concentrated on the effect of blade angle on the rotating speed for the different turbine models. Obviously, the results highlight that the maximum power coefficient has an inverse relation to the blade angle.

In the present work, the computational fluid dynamics (CFD) technique was used to predict the fire dynamics in a big three-story building. Important aspects of fire dynamics were investigated such as smoke propagation and temperature distribution. The study aims to decrease the fire hazards by computationally predicting the expected smoke movement in reallife conditions. Consequently, early evacuation plans can be established to save human lives by proper estimation of the smoke direction and density. Also, temperature rise has a potential effect on the safety of both humans and structures. Different factors were considered such as fire location, doors, and emergency openings. Important findings and notable conclusions are recorded.

This paper presents a CFD and experimental study of the thermal behavior of the thermoelectric-compartment in a hybrid household-refrigerator that combines thermoelectric and vapor-compression technologies. The hybrid refrigerator has three compartments. One of them is driven by a thermoelectric cooling system, which was made of one Peltier module and two fan-cooled heat sinks mounted on the hot and cold sides. The simulation results were compared with experimental measurements and showed a good agreement. The performance of the thermoelectric refrigerator was tested with changing the pushing direction. Two pushing directions for the fan were examined. In the first one (direction-I), the fan was fixed such that it sucked the air beside the cold heat sink. While in the second direction (direction-II), the fan was assumed to be flipped to push the air over the cold-side heat sink. The results showed that the second fan direction (direction-II) is more effective for heat transfer mechanism between the cold-side heat sink and the inside air of the thermoelectric-compartment.