Volume 2 Issue 3
Authors: Mohammadjavad Mahdavinejad; Maryam Fakhari; Fateme Alipoor
Abstract: The most energy consumption is in the building industry, about 40%, and the major part of which is spent for cooling, heating and ventilation. Therefore, using suitable measures to reduce energy consumption has a great influence on energy balance of building. One of the passive design methods is using a solar chimney as a mechanical eco concept which is a simple idea to increase natural ventilation in surrounding spaces. Solar chimney can be used vertically or in the angle of horizon. The inclination angle of solar chimney influences the ventilation rate efficiency. In the present study, the effect of solar chimney on ventilation rate has been examined in four cities of Iran with different climates. Due to lack of access to the implemented samples, the computerized simulation was used as alternative method for field studies, the results of which by energy plus software in four cities of different climates show that the optimum angle of inclination is 45° so that the maximum ventilation is obtained. The vertical position of chimney provides the minimum ventilation rate in all cities except in Tabriz (cold climate).
Keywords: Solar Chimney; Ventilation; Inclination Angle; Energy Simulation
Authors: Zhimin Li; Chun Li; Wei Gao; Yulong Wu
Abstract: The wind power develops rapidly in recent years. Designing and studying composite materials is one of the most important technologies of wind power. Based on the composite laminate theory and finite element analysis method, the composite wind turbine blades are analyzed. The shell element in ANSYS is used to simulate blade lay-up, and complete its strength analysis and modal analysis. Results of comparing the calculated and the experimental values of the blade mass, and center of gravity show that the blade lay-up design method is feasible. The structure analysis and comparison of different deformation on flap-wise and edgewise provided the basis for blade lay-up optimization.
Keywords: Blade; Composite; Lay-up; Structure Analysis
Authors: Kaveh Hariri Asli; Hossein Hariri Asli; Kasra Motlaghzadeh; Kian Hariri Asli
Abstract: The literature indicates that relatively little research is available to describe the relationship between factors which generate the water hammer phenomena. As a main purpose, present work is to define the computational modeling for drinking water transmission pipeline. Thus the dynamic model shows the validity of prediction achieved by nonlinear heterogeneous model in this work. The research question was formed by classification of the experimental results of laboratory model and the field test results. On the other hand, this work shows the relation between the parameters of water hammer phenomena, water column separation and entered air simulation. The method of research is regression statistical analysis method. In this work the regression method is based on the SPSS software with repeated measures for independent samples. As a dynamic modeling selection, the logarithmic function showed suitable correlation on scatter diagram. Consequently, the results of this work will help to reduce the risk of water transmission failure.
Keywords: Water Hammer; Nonlinear Heterogeneous Model; Infiltrated Air Simulation; Numerical Analysis; Characteristics Method