Iranian Society of Mechanical EngineeringIranian Journal of Mechanical Engineering Transactions of the ISME1605-972714120130301One Dimensional Internal Ballistics Simulation of Solid Rocket Motor51615330ENS. Gh. Moshir StekharehDepartment of Mechanical and Aerospace Engineering, Malek e
Ashtar University of Technology, Tehran, IRANA. R. MostofizadehDepartment of Mechanical and Aerospace Engineering, Malek e Ashtar
University of Technology, Tehran, IRANN. FouladiDepartment of Mechanical and Aerospace Engineering, Malek e Ashtar
University of Technology, Tehran, IRANA. SoleymanDepartment of Mechanical and Aerospace Engineering, Malek e Ashtar University of Technology, Tehran, IRANJournal Article20130201An internal ballistics model has been developed for performance prediction of a solid propellant rocket motor. In this model a 1-D unsteady Euler equation with source terms is considered. The flow is assumed as a non-reacting mixture of perfect gases with space and time varying thermo physical properties. The governing equations in the combustion chamber are solved numerically by using the Steger and Warming flux vector splitting scheme. After validation of results by experimental data, the effect of grain geometrical variables and solid propellant characteristics are studied on performance characteristics of a standard internal burning cylindrical grain. These parameters include of negative /positive erosive burning, propellant characteristics, port to throat area ratio and initial temperature of the propellant. The results of developed model show that, propellant characteristics are dominant factors which affect performance characteristics. When erosive burning rate are considered, the 1-D internal ballistic analysis have good agreement with experimental data.Iranian Society of Mechanical EngineeringIranian Journal of Mechanical Engineering Transactions of the ISME1605-972714120130301Multiple Moving Cracks in a Nonhomogeneous Orthotropic Strip173215331ENR. BagheriPh.D Student ,Faculty of Engineering, University of ZanjanM. AyatollahiMechanical Engineering, University of Zanjan,O. RahmaniMechanical Engineering, University of ZanjanJournal Article20131101The problem of several finite moving cracks in a functionally graded material is solved by dislocation technique under the condition of anti-plane deformation. By using the Fourier transform the stress fields are obtained for a functionally graded strip containing a screw dislocation. The stress components reveal the familiar Cauchy singularity at the location of dislocation. The solution is employed to derive integral equations for a strip weakened by several moving cracks. Numerical examples are provided to show the effects of material properties, the crack length and the speed of the crack propagating upon the stress intensity factor and strain energy density factor.Iranian Society of Mechanical EngineeringIranian Journal of Mechanical Engineering Transactions of the ISME1605-972714120130301Experimental Study of a High Speed Micro Waterwheel334715335ENY. YassiThe Mechanical Engineering Research Center of the Iranian Research
Organization for Science & Technology (IROST)Journal Article20131201Waterwheels are the oldest types of hydraulic machines. These turbines are of relatively simple design, large diameter, low rotational speed and high torques. But applying them as micro hydros of high speed and small diameter is yet to be explored. A micro hydro waterwheel of one meter diameter was designed and manufactured at the Iranian esearc†h Organization for Science and Technology (IROST) as a part of a joint research program between IROST and the Iranian Ministry of Power. The model turbine was then tested. Test results as standard turbine curves are also presented in this article. According to the results it was concluded that micro hydro waterwheels can operate efficiently at sites with high flow velocity.Iranian Society of Mechanical EngineeringIranian Journal of Mechanical Engineering Transactions of the ISME1605-972714120130301Model Predictive Control System Design using ARMAX Identification Method for Car-following Behavior487115336ENA. GhaffariMechanical Engineering Department, K. N. Toosi University of Technology, TehranA.R. KhodayariDepartment of Mechanical Engineering, Pardis Branch,
Islamic Azad UniversityS. SalehiniaMechanical Engineering Department, Shahid Rajaee Teacher Training University, TehranM. Nouri-KhajaviMechanical Engineering Department, Shahid Rajaee Teacher Training
University, TehranM.R. Arbab TaftiMechanical Engineering Department, Shahid Rajaee Teacher Training
University, TehranJournal Article20131101The control of car following is essential due to its safety and its operational efficiency. For this purpose, this paper builds a model of car following behavior based on ARMAX structure from a real traffic dataset and design a Model Predictive Control (MPC) system. Based on the relative distance and relative acceleration of each instant, the MPC predicts the future behavior of the leader vehicle and according to this behavior, the acceleration of the follower vehicle is controlled. Validation of the presented controller is done by comparing the behavior of the controller with the human drivers. Results show that the MPC controller has a behavior much safer than that of real drivers and it can provide a pleasant trip for passengers.Iranian Society of Mechanical EngineeringIranian Journal of Mechanical Engineering Transactions of the ISME1605-972714120130301Experimental Study on the Magnetomechanical Characteristics of Ni-Mn-Ga Ferromagnetic Shape Memory Alloy Single Crystals728415337ENR. AmrollahipourDepartment of Mechanical Engineering, Isfahan University of Technology, Isfahan, IRANM. KadkhodaeiDepartment of Mechanical Engineering, Isfahan University of Technology, Isfahan, IRANP. KameliDepartment of physics, Isfahan University of Technology, Isfahan, IRANJournal Article20131101Magnetic shape memory properties of Ni-Mn-Ga single crystals were characterized by measurement of stress-induced martensite reorientation under constant magnetic fields. Also magnetic field-induced strain as a function of the applied magnetic field under different constant compressive stress levels has been investigated. All the experiments were performed at room temperature in which the sample is in its martensite phase. Compressive stress and magnetic field were applied perpendicular to each other, and strain was measured along the compressive load axis. agnetoelasticity, martensite reorientation, shape memory effect, and pseudoelasticity were observed throughout the experiments. Moreover, twinning stress and blocking stress were obtained.