Iranian Society of Mechanical EngineeringIranian Journal of Mechanical Engineering Transactions of the ISME1605-972721220200901Prediction of the Remaining useful Life of the Rolling Element Bearings using Recurrent Neural Network4644010.30506/jmee.2020.46440ENM.A Bayati NezhadM.Sc., Mechanical Engineering Department, Shahid Rajaei University, Tehran, IranA MohammadiCorresponding Author, Assistant Professor, Faculty of Mechanical Engineering Department, Shahid Rajaei
University, Tehran, IranA Davood AbadiPhD Student, Mechanical Engineering Department, Sharif University of Technology, Tehran, IranJournal Article20201027In this paper, the temperature feature was employed to track<br />down the degradation trend of rolling element bearings. The<br />remaining useful life(RUL) of the rolling element bearing<br />was predicted by assuming root mean square growth (RMS)<br />of the acceleration signal to exponential function form and<br />extraction of two other features. Then, the performance of<br />these features was investigated in the prediction using a<br />recurrent neural network(RNN). The experimental data of<br />the accelerated life test on the rolling element bearing have<br />been extracted from the prognostic. Contrary to the<br />previous works, this paper considers the temperature<br />feature instead of the time feature and also assuming the<br />RMS of the acceleration signal to the exponential function<br />form and using a RNN which causes a new model more<br />applicable than previous models.Iranian Society of Mechanical EngineeringIranian Journal of Mechanical Engineering Transactions of the ISME1605-972721220200901Uncertainty Analysis of Spray Injection Process in a Model Scale Liquid Fuel Micro-Motor4644210.30506/jmee.2020.46442ENM NadjafiCorresponding Author, Assistance Prof. of Aerospace Engineering, Aerospace Research Institute (Ministry of
Science, Research and Technology), Tehran, IranM.A FarsiAssociate Professor of Aerospace Engineering, Aerospace Research Institute (Ministry of Science, Research
and Technology), Tehran, IranF OmmiProfessor of Mechanical Engineering, Tarbiat Modares University (TMU), Tehran, IranJournal Article20201027Injection process and its parameters are the most important<br />factors in the combustion process that depends on some<br />factors in operation. In this paper, initially, injection<br />parameters from viewpoint of macroscopic and microscopic<br />in a manufactured model scale liquid fuel micro-motor that<br />are measured experimentally in Cold-Test and Phase<br />Doppler Analyzer (PDA) laboratories, are evaluated. And<br />then, Uncertainty Analysis (UA) methodologies for<br />experimental uncertainty assessment are implemented to<br />drive the respective block diagram. The sources of<br />uncertainty associated with the techniques are presented,<br />and where such data were available, quantitative estimates<br />of their magnitude are given. Uncertainty analysis results<br />that are taken to spraying parameters show the high<br />accuracy of experimental test results. This framework is a<br />comprehensive and complete technique that could be<br />implemented and executed over any set to analyze<br />uncertainty value, with difference that each set or case study<br />has its respective parameters.Iranian Society of Mechanical EngineeringIranian Journal of Mechanical Engineering Transactions of the ISME1605-972721220200901An analytical study for nonlinear vibration analysis of two-directional functionally graded rectangular plate4500010.30506/jmee.2020.112273.1193ENSoheil HashemiFaculty of Mechanical Engineering, K.N. Toosi University of Technology, Tehran, IranAli Asghar JafariK.N Toosi UniversityJournal Article20190731In this study, an analytical solution is presented for investigating the nonlinear vibration analysis of two-directional functionally graded rectangular plate for the first time. On the basis of first order shear deformation theory (FSDT) and Galerkin procedure, the equations of motion are developed. The nonlinear equation of motion is then solved analytically by modified Lindstedt-Poincare method. The volume fraction distribution is assumed to be symmetrical for characterizing the in-plane material inhomogeneity. Finally, the effects of some system parameters such as non-dimensional vibration amplitude, volume fraction indexes and aspect ratio on the nonlinear to linear frequency ratio are discussed in detail. To validate the analysis, the results of this paper are compared with the published data and good agreements are found.Iranian Society of Mechanical EngineeringIranian Journal of Mechanical Engineering Transactions of the ISME1605-972721220200901Wind farm layout optimization using a Reynolds‐averaged Navier–Stokes model and a genetic algorithm4500110.30506/jmee.2020.112337.1194ENAbolfazl PourrajabianDepartment of Energy, Materials and Energy Research Center (MERC), 14155-4777, Tehran, IranReza EbrahimiK.N Toosi UniversityMorteza RahmanpourFaculty of Mechanical Engineering, Azarbaijan Shahid Madani University, Tabriz, IranSaeed RahgozarDepartment of Energy, Materials and Energy Research Center (MERC), 14155-4777, Tehran, IranMaziar DehghanDepartment of Energy, Materials and Energy Research Center (MERC), 14155-4777, Tehran, IranJournal Article20190801The placement of wind turbines in a wind farm can considerably affect the total output power. Using computational fluid dynamics and genetic algorithm, the optimal arrangement of turbines in a given wind farm was determined. A three-dimensional Reynolds-averaged Navier-Stokes simulation was conducted on a 660 kW three-bladed horizontal axis turbine. The airflow was assumed to be steady state and a pressure-based approach was adopted to solve the governing equations. Subsequently, an engineering expression for the wake evolution was developed and validated. By employing the characteristics of the wake propagation, the appropriate distances between the adjacent turbines were calculated. To find the optimal placement of the turbines, a purpose-built genetic algorithm was employed to minimize the objective function defined by the ratio of the wind farm cost to the output power. The results show that the final configuration is in line with the outcomes of the previous study. The sensitivity analysis of the genetic algorithm with respect to its parameters including the population size and the mutation rate was also performed to guarantee that the final layout is an optimal one.Iranian Society of Mechanical EngineeringIranian Journal of Mechanical Engineering Transactions of the ISME1605-972721220200901The Effect of Repeated Impact Loading on Reservoir Rock Properties4500310.30506/jmee.2020.115766.1204ENMarzieh Naderan TahanMechanical Engineering Department, Shahid Chamran University of Ahvaz, IranKhosro Naderan TahanMechanical Engineering Department, Shahid Chamran University of Ahvaz, IranSeyed Saied BahrainianMechanical Engineering Department, Shahid Chamran University of Ahvaz, IranJournal Article20191028The objective of this paper is to present the results of a research program launched to investigate the mechanism and amount of changes of reservoir rock properties due to pulse stress waves. These waves are induced in cylindrical samples by applying repeated impact loading along the sample axes in a falling weight testing apparatus. The samples are dry and free from any fluid and no confining pressure. After each step of loading, permeability, effective porosity, wave velocities are measured by standard methods and CT images are prepared. Results show that if the amplitude of dynamic stress exceeds the dynamic fracture strength and spall strength of the samples, micro fracture will emerge and permeability will increase significantly while the effective porosity decreases at first steps of loading but, recovers during the subsequent steps. Emerging and growth of new fractures are visible in CT images, too. Initial structure of samples, total energy consumption prior to complete breakage, and the strain rate of incident wave, affect the results.Iranian Society of Mechanical EngineeringIranian Journal of Mechanical Engineering Transactions of the ISME1605-972721220200901Free and forced vibration behavior of cylinders made of two dimensional functionally graded materials using meshless method4500410.30506/jmee.2020.117657.1210ENHabib MirzaieDepartment of Mechanical Engineering, Ahvaz Branch, Islamic Azad University, Ahvaz, IranSeyed AliReza Seyed RoknizadehDepartment of Mechanical Engineering, Ahvaz Branch, Islamic Azad University, Ahvaz, Iran0000-0002-0133-7292Journal Article20191128In this article, a meshless method is developed to analyze free and forced vibration behavior of axisymmetric cylinders made of two dimensional functionally graded materials (2D-FGMs). The meshless method is based on weak form of equations of motions using the Moving Least Square (MLS) approximations shape functions. The 2D-FGM cylinders are made of a mixture of a ceramic and a metal. The volume fraction of each component is assumed to be functionally varied along both radial and axial directions of cylinders. The effects of profile of material distributions, cylinder dimensions, boundary conditions and loading on the vibrational characteristics of the proposed 2D-FGM cylinders are investigated. The results of investigating the vibrations of the cylinders made of 2D-FGM confirmed that in the engineering design applications, the radial vibrations can be attenuated by adjusting the power coefficients along the radius and length of the cylinder.Iranian Society of Mechanical EngineeringIranian Journal of Mechanical Engineering Transactions of the ISME1605-972721220200901Robust sliding mode control of uncertain nonlinear ship autopilot system 4500510.30506/jmee.2020.118967.1220ENFarzan RashidiUniversity of HormozganAbbas HarifiUniversity of HormozganJournal Article20191222Designing of ship autopilot has been a challenging problem because of high nonlinearity of ship dynamics and various acting disturbances. Hence, In the last few years, many classical and intelligent algorithms are presented in the literature, for better control of ship autopilot. The main goal of the work is to design a proper and efficient controller for ship autopilot based on sliding mode control method. The major contribution of the paper is employing a nonlinear model as well as considering dynamic bounds of uncertainties for controller design. In order to reduce the chattering phenomenon, control scheme has been modified using integral switching variable. Simulation results in the rough wave condition show the success of method to overcome nonlinearity and disturbances, and high performance of the proposed controller comparing to similar research.