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Open Access Article
1 - Low cycle fatigue prediction for cylinder head considering notch stress-strain correction proposed by Neuber
Hojjat AshouriDue to the complex geometry and loading conditions, engines cylinder heads are the most challenging components among all parts internal combustion engines. They must withstand severe cyclic thermo-mechanical loading throughout their lifetime. Low cycle fatigue (LCF) pre MoreDue to the complex geometry and loading conditions, engines cylinder heads are the most challenging components among all parts internal combustion engines. They must withstand severe cyclic thermo-mechanical loading throughout their lifetime. Low cycle fatigue (LCF) prediction for cylinder head considering notch stress-strain correction proposed by Neuber was investigated. For this purpose, first Solidworks software was used to model the cylinder head. Then Ansys Workbench software was used to determine temperature and stress distribution of the cylinder head. Finally, in order to study the fatigue life based on LCF approach, the results were fed into the nCode Design Life software. The thermo-mechanical analysis showed that the maximum temperature and stress happen in the valves bridge between the two exhaust valves. The results of the FEA correspond with experimental tests performed by researchers, and demonstrated the cylinder heads cracked in this region. The numerical results showed that the area where the maximum temperature and stress is occurred is where the least LCF is predicted. Manuscript profile -
Open Access Article
2 - Table of Contents
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Open Access Article
3 - A quick method for electrical energy system load shedding based on equivalent areas
Shahrokh Shojaeian Hamed SoltaniThe main purpose of the paper is to present a fast load shedding scheme, based on the concept of equivalent areas in large power systems. Performing load shedding on such systems with several generators in each area by using the conventional method is consuming a large MoreThe main purpose of the paper is to present a fast load shedding scheme, based on the concept of equivalent areas in large power systems. Performing load shedding on such systems with several generators in each area by using the conventional method is consuming a large amount of time. The proposed method can significantly reduce energy not supplied and is absolutely affordable for not only energy producers, but also energy consumers. At first, the coherent generators in the network will be detected based on a generation acceleration technique. The coherent generators will be identified without performing transient stability studies or the comparison of rotor swing angles, and only will be detected by using Jacobian matrix elements of the linearized power system model. Each group of the coherent generators will be replaced by an equivalent generator to introduce a new reduced model. All analytical calculation and decision variable factors will be achieved centrally with mentioned model and the only signal sends to the network, is a load shedding command. UVLS technique will be applied to the load shedding scheme. In this method, the priority is to shed the busloads with the most amplitude of the voltage drop after disturbance, so the network voltage and frequency stability will be maintained. The scale of load shedding level is proportional to online mismatch power between generation and demand. Finally, a simulation of the standard 39-buses IEEE network will be carried out to prove the strategy’s effectiveness. Manuscript profile -
Open Access Article
4 - Investigating the performance of hydroponic green fodder and simplified heat transfer model of nanofarm for agricultural engineering application
Amirreza Esmaeili Hamidreza Bahrami Rozita Hajian Mohsen Karimian Ehsan ShokraniIn this study, root length and number of roots in forage production were investigated by hydroponic nanofarm chamber. For this purpose, specific amount of corn was planted in a special metal nanofarm culture room in two floors equipped with automatic control system. Aft MoreIn this study, root length and number of roots in forage production were investigated by hydroponic nanofarm chamber. For this purpose, specific amount of corn was planted in a special metal nanofarm culture room in two floors equipped with automatic control system. After 6 and 7 days of growth of corn from treated and non-treated sample were randomly selected. The amount of performance of the nanofarm was considered as humidity, temperature, and light parameters. In this research, an experimental observation on nanofarm device was done to check the grow and cultivate corn fodder with and without 202020 fertilizers. Also, the evaluated NFT system was used for prediction and simulation of hydroponic nanofarm. According to our study, there are more than 900 different agricultural products used to make animal feed in which green fodder has the most important response in the agriculture field. The efficiency of seed to fodder in this system is about 1 Kg to 7 Kg of seed (barley), an average of 7 Kg of barley fresh fodder hydroponic can be obtained. This system can have less waste product and higher efficiency. One of the main goals of the control system in Nanofarms is to control the temperature of the internal environment of Nanofarm. In the discussion of nanoform heat transfer, various methods of heat transfer, including conduction, displacement, and radiation are of interest. Manuscript profile -
Open Access Article
5 - Road detection by image processing, using neural network
Ahmad Keshavarzi Mehdi Keshavarz Alireza MoradiOne of the methods in road detection is image processing, which is detected according to the contents of the image captured by the car camera. Much research has been done in this area by researchers, who have used a variety of methods to better process the road and dete MoreOne of the methods in road detection is image processing, which is detected according to the contents of the image captured by the car camera. Much research has been done in this area by researchers, who have used a variety of methods to better process the road and detect the direction of vehicle movement. Using the photos taken by the camera installed on the car and their preprocessing, such as removing inefficient corners and turning it into a gray photo during various stages and applying a goblin filter on the photos and extracting the tallest diagram in order to detect the direction of the road. In this research, standard data processing such as line slope for neural network input and LVQ neural network are used to process road images and detect road direction based on three directions: straight, left and right. IAfter several experiments, it was found that the slope of the line in the full photo could not represent the route of the road, therefore, the photos were divided into two, three and four parts and another effective parameter in the system. the seven layers were used to start the neural network training and each time the number of layers increased and the processing results were compared. The best answers were obtained for the number of layers above 70, which is a small difference between the photos divided into three and Four were observed and with a difference of 2%, the four-part photos gave us the best answer. Manuscript profile -
Open Access Article
6 - Secondary frequency control for improved dynamic performance in interconnected power system
Farhad Mesrinejad Somaye Yaghoubi Bahador FaniLoad changes affect the frequency of electrical networks. Frequency stabilization is very important due to the increasing penetration of renewable energy sources in power systems. The main task of load frequency control is to keep the system frequency according to the s MoreLoad changes affect the frequency of electrical networks. Frequency stabilization is very important due to the increasing penetration of renewable energy sources in power systems. The main task of load frequency control is to keep the system frequency according to the specified nominal value and to maintain the correct amount of exchange power between the control areas. Load frequency control in two-area power system is studied and simulated in this paper. Each area has a steam generating unit with a reheat steam turbine. The system equations are expressed in the state space and the system model is determined based on the transfer function. The simulation results have been obtained using Matlab software. The simulation results show the effect of reheater on the transient dynamic behavior of the two-area power system. Manuscript profile -
Open Access Article
7 - Static analysis of guyed tower regarding cable sagging by using finite difference model
Kaveh Kumarci Alireza BaharizadehThe static analysis of guyed towers is very complex because of high degree of non-linearity they exhibit due to their slender and flexibility. In the static analysis of cable systems, due to the effects of nonlinearity of loading and large functions, the interference of MoreThe static analysis of guyed towers is very complex because of high degree of non-linearity they exhibit due to their slender and flexibility. In the static analysis of cable systems, due to the effects of nonlinearity of loading and large functions, the interference of loads and displacement have no much value. Because of having no analytical solution for these systems, numerical methods have been applied. Finite difference method (FDM) is one of the known methods which are directly related to nonlinear relative equations and, the cable system is defined using calculating of them and deformation equations . In this research, the non-linear analysis of cables under three dimension static loads is analyses using FDM. This model can be analyzed three dimension response of cable using sequential method. In this model, long and inclined pre-tensioned cables have been studied in which only axial stiffness of cable is considered while bending and torsion stiffness are assumed to be negligible. Manuscript profile
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