Showing 4 results for Faezian
Hamid Yazdanpanah, Anoshirvan Farshidianfar, Ali Ahmadpour, Ali Faezian, Farid Mokhtari,
Volume 16, Issue 7 (9-2016)
Abstract
Reduction of unwanted noises is an important issue in the current societies regarding their potential negative impact on the mental and physical health of the peoples. Researchers are trying to find a new method to reduce the damage of this unwanted sound. Accordingly, the use of sound absorbing materials with appropriate acoustic properties has increased in the recent years. In this article, the production of polyurethane foam explained first and sound absorption coefficient of pure PUF has been measured. In order to improve the mechanical and acoustical properties of polyurethane foam, various quantities of Nano-Alumina powder is added to the structure of the foam. The effects of this additive material on the acoustic and mechanical properties of the foam are then measured. In this work, for the first time, the mechanical, physical and acoustical properties of the polyurethane foam improved by Nano-Alumina are studied. Finally, the change of the sound absorption coefficient of the produced composite material is analyzed based on the mechanical and physical experimental results. The sound absorption coefficient of this foam is then measured using two microphone method with Impedance tubes.
M. Hosseinzadeh, S.m. Mirzababaee , H. Zamani, A. Faezian, F. Zarrinkalam,
Volume 19, Issue 7 (July 2019)
Abstract
In this study, the performance of an evacuated tube solar cooker analytically investigated. For this purpose, the heat transfer mechanisms in different components of the solar cooker is evaluated. The main aim of this article is to investigate the important parameters of the evacuated tube solar cooker in different weather conditions using the validated analytical model. The studied parameters are: wind speed, ambient temperature, and input solar radiation. The experiments performed at the Research Institute of Food Science and Technology, Mashhad, Iran (Latitude: 36° and Longitude: 59°).
The results reveal that the presented analytical model is an accurate model that can be used in the paramedic analysis of the evacuated tube solar cooker. Moreover, in the
reference weather conditions, the lost heat contains
only 12.22 W of the absorbed solar radiation (137.51 W).
Therefore, about 8.89% of the absorbed solar radiation is lost. Based on the results, the temperature of outer surface of the cooker is only 3.64
°C higher than the ambient temperature due to the vacuum between the tubes. In addition,
the evacuated tube solar cooker has proper performance in various weather conditions. Increasing the ambient temperature from 5 °C to 35 °C enhances the solar cooker efficiency by 0.65%.
M. Hosseinzadeh, H. Zamani, S.m. Mirzababaee, A. Faezian, F. Zarrinkalam,
Volume 20, Issue 6 (June 2020)
Abstract
In this study, a portable parabolic solar cooker is designed and fabricated, and the daily performance of the solar cooker is investigated from the energy and exergy viewpoints. One of the important challenges of the parabolic solar cookers is the reduction of their performance in the windy conditions. In order to evaluate this issue, the effect of 0.2, 2, 4 and 6m/s wind speeds on the energy and exergy efficiencies of the solar cooker is studied. Based on the results, the energy efficiency of the parabolic solar cooker is 34.52-46.19% and the exergy efficiency is 2.11-5.60% during the experiment. The experimental results indicate that water can boil in the windy conditions using the fabricated solar cooker although the time required to boil water increases by rising the wind speed. According to the results, in the wind speed of 6m/s, the time taken to boil 2 liters of water is about 40min. Furthermore, the energy and exergy efficiencies of the parabolic solar cooker in the wind speed of 6m/s are 20.08% and 1.99%, respectively, lower than those in the wind speed of 0.2m/s.
Razieh Abedini, Faezeh Najafi, Mohammad Passandideh-Fard, Amir Abdolah, Ali Faezian,
Volume 23, Issue 8 (August 2023)
Abstract
In this article, the numerical and experimental investigation of the effect of ultrasonic waves on the heat transfer rate with an increase of the wave amplitude is discussed. Numerical modeling determines the possibility of the investigation of the ultrasonic wave’s effects on fluid flow distribution and heat transfer. For this purpose, a cylindrical tank is considered inside which a spiral heater is placed at a fixed height in the water. In addition, ultrasonic transducers are considered as circular plates under the bottom of the tank. In order to simulate, the ANSYS Fluent software is used and the modeling is accomplished in two stages before and after ultrasonic excitation. To validate the numerical results, they are compared with those of the experiments. For this purpose, an experimental setup is prepared witch consists two coaxial cylinders, a spiral heater kept at a certain height in the water, and five transducers attached to the bottom of the tank. Both experimental and numerical results show that the convection heat transfer coefficient increases with the use of ultrasonic waves with a discrepancy of nearly 4% between the results. By increasing the heat transfer coefficient, the heater surface temperature decreases. The discrepancy between the measured and calculated temperature is about 5%. The velocity and temperature distributions obtained from the numerical results show that using ultrasonic waves enhance the fluid flow mixing which in turn increases the convection heat transfer. The higher the amplitude of the ultrasonic wave, the higher the heat transfer coefficient will result.
