نشریه مهندسی مکانیک و ارتعاشات
سال پنجم شماره 3 (پیاپی 16، پاییز 1393)

The purpose of this article is to determine energy absorbing of empty conical tubes. In these innovated models, there are a handful of rectangular grooves around the inner and outer surface of the tube. In this study, effects of number of grooves and their semi apical angel on Energy Absorption, Specific Energy Absorption (SEA), maximum crush load and Crush Force Efficiency (CFE) are considered. The energy absorbing system can be used in the aerospace industry, shipbuilding, automotive, railway industry and elevators used to absorb impact energy. Finally, appropriate geometric parameters and the best examples of criteria considered with respect to the objectives, are introduced.

Since more than one‐third of the world's energy consumption is in building part, green buildings and sustainable architecture are new ways to cope with the environment and reduce energy consumption in their buildings. The use of Trombe wall in residential, commercial and official buildings has been reduced energy consumption and solar energy storage with phase change materials will double this effect. This has caused a paradigm shift towards green building design, and ultimately the environment will be less polluting. Therefore, in this study, the effect of natural Convection on performance has been investigated on Trombe wall with phase‐change material by change of size and location of incoming and outgoing air intake dampers. This research has been conducted experimentally and numerically. After construction of Trombe wall with phase‐change material and empirical data collection, physical conditions are simulated in FLUENT software and experimental results have been compared with numerical solutions. The results show resized Trombe wall dampers; have been increased outlet air temperature by 16 percent. The location change of dampers at the horizontal line does not increase the effect of output air temperature. 2 percent difference between the numerical results with experimental data represents the careful work and analysis.

The purpose of this article is to develop a thermodynamic model appropriate to be piston Stirling engine beta-type deformation is to increase efficiency and output power l. For this purpose, thermodynamic modeling is done in two parts, the first part was isothermal modeling and then using the results of numerical modeling to model the geometry of adiabatic method is performed. In fact, the results of the first part (modeling isothermal), as initial values of the second part (modeling adiabatic), is used. Modeling was performed using MATLAB software and by changing the diameter of the piston, the heat input, heat output and engine efficiency. The results obtained were compared with published values, compared.