eng
Menoufia University, Faculty of Engineering
ERJ. Engineering Research Journal
1110-1180
2020-10-01
43
4
261
271
10.21608/erjm.2020.112769
112769
Original Article
Investigation of Resonance and Ferroresonance Overvoltages due to Cable-Transformer Interactions
Alyaa Nassar
eng_alyaa2010@yahoo.com
1
Abdel-Maksoud Taalab
taalab3@yahoo.com
2
Mohamed Izzularab
mizzularab@sh-eng.menofia.edu.eg
3
Nagy Elkalashy
nagy.elkalashy@sh-eng.menofia.edu.eg
4
Electrical Engineering Menoufia University
Electrical Engineering Department, Menoufia University
Electrical Engineering Menoufia University
Electrical Engineering Department, Faculty of Engineering, Menoufia University
In this paper, the resonance and ferroresonance phenomena are deeply investigated considering two different cable-transformer power systems. The internal transformer resonance overvoltage case is initiated due to a single-phase earth fault, while the studied ferroresonance case is due to a single-phase switching in the source feeding an unloaded transformer via a power cable. The resulted secondary overvoltage and the core flux signatures are used as a classifier, where the transient features are extracted using three algorithms. Although the voltage frequency spectrum and phase-plane diagrams have been previously utilized for the ferroresonance mode evaluation, they are exploited in this paper for the comparison study and accordingly for the detection of resonance and ferroresonance phenomena. Salient features found in the transients extracted using the well-known DWT are used as inputs of the third algorithm. A new detection approach is attained based on the DWT-based transient feature extraction of resonance and ferroresonance overvoltages.
https://erjm.journals.ekb.eg/article_112769_088af03077c43913b63f58bf3109292e.pdf
Resonance and ferroresonance overvoltages
Cable-Transformer interaction
Phase-Plane diagram
DWT
eng
Menoufia University, Faculty of Engineering
ERJ. Engineering Research Journal
1110-1180
2020-10-01
43
4
273
284
10.21608/erjm.2020.112777
112777
Original Article
A Modified Single-Stage Three-Phase Boost Inverter for PV Applications
Dina Osheba
engdina20085@yahoo.com
1
Haitham azazi
haitham_azazi@yahoo.com
2
Osame Mohamed
engosama_87@yahoo.com
3
Azza Lashine
azzalashine@yahoo.com
4
electrical engineering,Faculty of engineering,menoufia university
Electrical Engineering, Faculty of Engineering, Menoufia University
Mechanical & Electrical Research Institute, National Water Research Center, Egypt
Electrical engineering department, faculty of engineering, Menoufia University, Egypt
This paper proposes a single-stage three-phase boost inverter for Photovoltaic (PV) applications. The proposed circuit topology is directly step-up the input low level DC voltage to a high-level output AC voltage in only one stage, using an inductor and six switches. A new control methodology is introduced to regulate the AC output voltage and current and is suitable for grid-connected and stand-alone applications. The proposed circuit uses only six switches of a simple type of switches that achieve the desired objectives easily without additional antiparallel diodes. The circuit topology is extensively analysed and the overall performance including total harmonic distortion (THD) is obtained by computer simulation and presented under different conditions. A DSP-based laboratory model is built to assess the proposed single-stage three-phase boost inverter when fed from a PV source. The experimental results confirm the simulation, illustrating the successful operation of the proposed circuit topology to produce three-phase AC output from the low DC voltage of the PV source.
https://erjm.journals.ekb.eg/article_112777_926e04ee043f2eebbc5fc526c77603fb.pdf
renewable energy
Single-Stage converters
Boost Inverters and three-phase boost inverter
eng
Menoufia University, Faculty of Engineering
ERJ. Engineering Research Journal
1110-1180
2020-10-01
43
4
285
292
10.21608/erjm.2020.112780
112780
Original Article
Mathematical Model of a Cracked Pipeline Subjected to Sinusoidal Force Excitation
Ibrahim El Fahham
ibrahim.elfahham@alexu.edu.eg
1
Abdallah Al Kaood
abdallaalkaood@yahoo.com
2
Hassan El Gamal
ha_elgamal@yahoo.com
3
Mechanical Eng. Department, Faculty of Engineering, Alexandria University Alexandria, Egypt
Mechanical Engineering Department, Faculty of Engineering, Alexandria University, Egypt
Mechanical Engineering, Mechanical Engineering Department, Faculty of Engineering, Alexandria University, Egypt
The present work introduces a mathematical model of a cracked pipeline conveying liquid. This model uses governing equation of Euler – Bernoulli beam theory for a pipe conveying liquid. The crack introduced in the model is represented by two identical torsional springs and a sinusoidal excitation force was applied to one of the pipe ends for the purpose of crack detection. The model is solved numerically using MATLAB code bvp4c to solve linear, ordinary fourth order differential equations (boundary value problem) for the detection of the crack position. To group the variables in the dimensionless form, Buckingham Pi-theorem was used. The effects of the dimensionless parameters on crack position were examined. The results show that the value of dimensionless parameters of stiffness at crack and support has considerable effect on crack position. It also shows that the force amplitude and fluid flow properties has no effect on crack position which demonstrates the capacity of using the present technique with small force magnitude to avoid stress-strain problems on the pipeline and any excitation frequency can be used.
https://erjm.journals.ekb.eg/article_112780_0aca5d5cc13047549efab888d170444f.pdf
Mathematical Models
Lateral vibration
Pipeline
Crack position
Dimensional analysis
eng
Menoufia University, Faculty of Engineering
ERJ. Engineering Research Journal
1110-1180
2020-10-01
43
4
293
304
10.21608/erjm.2020.112782
112782
Original Article
An Investigation of Using Microchannel Condenser to Improve the Performance of Air Conditioning Unit
Mostafa Abdel-Baky
mostahmed2004@yahoo.com
1
Mousa Mousa
mousamohamed@yahoo.com
2
Abdel-Fattah Koraim
abdelfattah-aly@elarabygroup.com
3
Mechanical Power Engineering, Faculty of Engineering, Menoufia University
Mechanical Power Engineering Department, Faculty of Engineering, Menoufia University, Shebin El-Kom, Egypt.
Mechanical power engineering, Faculty of Engineering, Menoufia University
In the recent years, many researches have been focused towards the new technology in heat exchangers. Besides, the economy of manufacturing takes up a great attention of scientific works. Through this work the use of microchannel condenser achieves increase in energy. The study was conducted on two air conditioning units utilize R-22 as a refrigerant and having different cooling capacities 3516 W and 5274 W. The results showed that the use of microchannel condenser achieves increase in Energy Efficiency Ratio (EER) which reflected on the total efficiency of the device and reduce energy cost. The obtained results indicated that, the use of microchannel condenser led to increase in EER by (4.3:11.3%) for the first unit and and (9.5:29%) for the second one compared with that unit use FTC. Also, the use of MChC led to decrease the pressure drop by (20%:30%) while the convective heat transfer coefficient is improved by (61.6:84.1%).
https://erjm.journals.ekb.eg/article_112782_bdc7cc17a3e8ab5e4d454c0f673a428e.pdf
Michrochannel condenser
Michrochannel heat exchanger
Window air conditioner
refrigeration
Energy efficiency ratio.
eng
Menoufia University, Faculty of Engineering
ERJ. Engineering Research Journal
1110-1180
2020-10-01
43
4
305
312
10.21608/erjm.2020.112797
112797
Original Article
Low Friction Clutch Using Planetary Gears and Cams Mechanisms (Part I: Idea and Preliminary Design)
Khaled khader
khkhm62@hotmail.com
1
Production Engineering and Mechanical Design, Faculty of Engineering, Menofia University, Egypt
Research progress in the automotive industry sector is highly motivated by scarcity and rapid depletion of the fossil fuels. Hence, designing automotive components that could support decreasing power losses is critical to efficient use of fuel. Clutches are basic elements in automotive industries for controlling motion transmission. Furthermore, loss of power related to the "spin loss" phenomenon in clutches significantly affects the motion transmission efficiency. Therefore, automotive industry developers are looking forward to develop advanced clutches that yield to low losses associated with quick response. The friction in clutches' disks is a main source of power losses. Also, the friction affects the clutches life time which causes sudden troubles. This paper presents a conceptual design of low friction clutch using permanent magnet cylinders, planetary gears and cams mechanisms for reducing loss of power in order to improve system efficiency. This clutch uses the magnetic forces effect of magnetic cylinders instead of the direct contact effect of the regular clutch's friction disks. Also, this clutch is provided with cams mechanism for assuring that motion is completely stopped. Moreover, planetary gears of this clutch decrease rotation speed and increase torque as an initial reduction gear box. Finally, a prototype of this clutch is presented for testing the conceptual design validity.
https://erjm.journals.ekb.eg/article_112797_ab4eca5a764f0d5379f3f8eb004e343a.pdf
Mechanism
Cams
Clutch Design
planetary gears
eng
Menoufia University, Faculty of Engineering
ERJ. Engineering Research Journal
1110-1180
2020-10-01
43
4
313
325
10.21608/erjm.2020.112798
112798
Original Article
Improving the Performance of Vertical Wind Turbine Using Gears and Timing Belt Mechanism to Reorient the Turbine's Blades
Khaled khader
khkhm62@hotmail.com
1
Production Engineering and Mechanical Design, Faculty of Engineering, Menofia University, Egypt
Vertical Axis Wind Turbines (VAWTs) are steadily continued to gain more attention from both academia and governments as they can provide promising solutions for harnessing wind energy in locations with modest wind speeds as well as varying wind directions. In spite of all of the flexibility in working conditions as well as low installation costs and ease of maintenance associated with the VAWTs, their lower efficiency levels significantly obstruct their competiveness in the wind energy field. Therefore, enhancing the performance of such turbines is very critical in exploiting their full potential. Accordingly, this paper proposed a mechanical mechanism which is mainly consists of gears and timing belt that are specially designed to effectively enable the turbine blades to instantaneously reorient themselves to face the wind direction. Also, the proposed turbine is enclosed in a specially designed cage with a rear blade attached to it. This rear blade, as affected by the wind, is responsible for making the cage redirect itself such that its inlet is facing the wind direction. To test the validity of the introduced concept, a VAWT prototype with the proposed mechanism has been manufactured and tested using wind tunnel. The test results demonstrated the self-oriented capability of new design that guaranteed maintaining a continuous perpendicular position between the affecting wind direction and the blade surface. The experimental results also confirmed the expected efficiency improvements and the assessed natural theoretically frequencies ensured that the developed turbine can safely rotate with considerably high angular speeds with no resonance risks.
https://erjm.journals.ekb.eg/article_112798_63447cf85cd47ed071d3f857c022cbe2.pdf
Gears and Timing Belt Mechanism
Self-Oriented Blade
Vertical Axis Wind Turbine (VAWT)
Finite Element
eng
Menoufia University, Faculty of Engineering
ERJ. Engineering Research Journal
1110-1180
2020-10-01
43
4
327
336
10.21608/erjm.2020.112799
112799
Original Article
Flexural and Shear Strengthening of RC Beams with Large Openings by Steel or CFRP Plates
mohamed kandil
eng.mohamed3000@yahoo.com
1
gaylan el gadaa
eng.gaylan_mohran@hotmail.com
2
Nageh Meleka
nagehmeleka@hotmail.com
3
Civil Engineering Department, Faculty of Engineering of Shebin El kom, Menoufia University
B.Sc. Civil Engineering Department 6 October University, 2012, cairo
Professor, Civil Eng. Dept., Faculty of Engineering, Menoufia University
Existence of transverse openings in the web of reinforced concrete beams is usually used to provide paths for required ducts and pipes which are necessary to accommodate essential services like water supply, sewage, air-conditioning, telephone and electricity. However providing an opening in the beam reduces its stiffness, which decreases the overall strength. The provision of openings through the beam depth, changes its simple mode of behavior to a more complex one depending on the size, shape and location of openings. Repair and strengthening of an existing structure may be essential in many cases such as increasing the stiffness of the beams due to making transverse openings in the web of beams after construction. An experimental test program of fourteen RC beams with large openings were strengthened by using additional layers of externally bonded steel plates or CFRP Plates with different techniques then tested by four-point bending test. The behaviors of the tested specimens were investigated with and without strengthening and compared to identify the effectiveness of each method and material of strengthening to increase the flexural and shear strength of beam with different opening location. The research shows that strengthening using CFRP Plates were more effective than using steel plates.
https://erjm.journals.ekb.eg/article_112799_393c55c3f849ea3bdc961b8394ee11d8.pdf
RC beams
Large Openings
strengthening
Steel plates
CFRP Plates
eng
Menoufia University, Faculty of Engineering
ERJ. Engineering Research Journal
1110-1180
2020-10-01
43
4
337
343
10.21608/erjm.2020.112800
112800
Original Article
Feasibility of Using Recycled Asphalt Pavement Aggregates in Concrete Pavement
mohamed abouelenain
eng_tahael3513@yahoo.com
1
Metwally Abd Elaty
drmet2828@yahoo.com
2
Mariam Ghazy
dr.mariamghazi@yahoo.com
3
kafr elseikh university
Faculty of Engineering, Tanta University, Tanta, Egypt
Prof. of Properties and Strength of Materials, Dept. of Civil Engineering, Faculty of Engineering, Tanta University
The feasibility of using concrete containing recycled asphalt pavement (RAP) in concrete pavement applications was evaluated. Recycled asphalt pavement (RAP) is the removed pavement material containing asphalt and aggregate. However, limited researches have been done to examine the potential of incorporating RAP into concrete. Since RAP contains asphalt, it is very likely that the toughness of concrete made with RAP could be improved. An alternative use of RAP is to use it as an aggregate in Portland cement concrete (PCC). Concrete containing 0%, 15% and 30% of RAP replacement by weight of natural coarse aggregates with different cement content with (250, 300 and 350 kg/m3) were produced in the laboratory and evaluated for their properties that are relevant to performance of concrete pavements. Mechanical properties of the concrete mainly compressive strength, modulus of elasticity and Poisson’s ratio after 28 days were recorded. The test results indicated that, the modulus of elasticity was found to decrease as the RAP content of the concrete increased, due to a decrease in the compressive strength of the concrete. However, these results as RAP were incorporated in the concrete, the resulting of compressive strength to modulus of elasticity and Poisson’s ratio for the concrete was reduced as compared with mixes that of a reference concrete without RAP. This indicates that, using a concrete containing RAP could possibly result in improvement in the performance of concrete pavements. Moreover, RAP could be used into Portland cement concrete without any modification to the conventional equipment or procedures.
https://erjm.journals.ekb.eg/article_112800_9f87029db07cc455b88f54a8f936a4cf.pdf
Portland cement concrete
Recycled asphalt pavement (RAP)
Mechanical Properties
Modulus of elasticity
Stress-strain relationships
eng
Menoufia University, Faculty of Engineering
ERJ. Engineering Research Journal
1110-1180
2020-10-01
43
4
345
354
10.21608/erjm.2020.112802
112802
Original Article
Evaluating the Effect of Different Passive Cooling Techniques of Roofs on Energy Consumption in the Buildings in Upper Egypt Using BIM
Nawal Ali
nawal_omar@techedu.sohag.edu.eg
1
Fatma Mohamed
fatma.ossman@gmail.com
2
Mohamed El-Hefnawy
mhelmy1974@yahoo.com.au
3
Construction dep, Technology & Education faculty, Sohag University, Sohag, Egypt
Architecture dep, Faculty of Engineering, Sohag University, Egypt
Architecture, Fine Arts Faculty, Assuit University, Egypt
The annual energy consumption rate in Egypt rises by 3.8% every year; traditional resources represent 92% of the generated energy. Taking into consideration the near depletion of their reserve and the included environmental issues with their use, it can be imagined that the energy situation in Egypt is disastrous. Therefore, improving the energy situation in Egypt became an urgent need. Reducing energy consumption in buildings, in particular, will help in reducing the overall consumed energy, since they consume 85% of the total energy production in Egypt. The design of roof slabs for thermal insulation purposes is required to reduce the energy consumed in buildings since they are accountable for 50% of the heat gain in a one-story building. By implementing passive cooling techniques, there are the chance to overcome the increased heat gain through roofs to reach the desired savings in energy. This search aims to evaluate the effect of different passive cooling techniques, applied to a student housing building's roof in Sohag University in new Sohag city in Upper Egypt, using building information modeling (BIM) platform. A review of the related scientific papers was carried out. Through this review, a matrix of 31 variables was conducted and applied to the building's roof. Energy consumption for every variable was calculated and compared to other variables. The findings proved that choosing the right passive techniques for roofs can help in reducing energy consumption by 46%. Also, some of these techniques may have a small effect on energy consumption.
https://erjm.journals.ekb.eg/article_112802_79ebc99c356c3c3b0badde3c80677fb1.pdf
Passive Cooling
BIM
Roofs
Upper Egypt
eng
Menoufia University, Faculty of Engineering
ERJ. Engineering Research Journal
1110-1180
2020-10-01
43
4
355
367
10.21608/erjm.2020.112803
112803
Original Article
Analysis of Different Stenotic Geometries on Two-Phase Blood Flow
Ramzy Abumandour
ramzy_0000@yahoo.com
1
Samy EL-Behery
s_elbehery@yahoo.com
2
Mohamed Kamel
m_kamel21@yahoo.com
3
Ahmed Dawood
ah_saed_dawood@yahoo.com
4
Islam Eldesoky
eldesokyi@yahoo.com
5
Basic Engineering Sciences Department, Engineering Faculty, Menoufia University
shebein elkom- menofia
Engineering Mathematics and Physics Department, Faculty of Engineering, Cairo University, Giza, Egypt
Department of Basic Engineering Science, Faculty of Engineering, Menoufia University, Shebin El-Kom, Egypt
Basic Engineering Sciences Dep., Faculty of Engineering, Shibin Elkom , Elmenoufia , Egypt
There are many different mathematical models and solution techniques dealing with the blood flows. A two-phase (liquid-solid) model solved by a perturbation method will be introduced. Effects of hematocrit, Reynolds number, area reduction, and different geometries of the stenotic channel are studied on the velocity, pressure gradient, and streamlines. The flow characteristics (velocity and pressure) give a great increase as the stenosis classified as a sever stenosis. It is found that, the stenosis geometry has a great effect on the pressure gradient in the axial direction, and also there is a change in velocity profile in each cross section of the geometry. The hematocrit has a noticed effect on the flow velocity and pressure gradient, in which as the hematocrit increases the maximum velocity decreases before the throat while it increased after that section.
https://erjm.journals.ekb.eg/article_112803_1a2edd38f216621f336cd9385a39aa83.pdf
Stenotic geometry
Two-Phase-Flow
incompressible flow
No-slip conditions