eng
Menoufia University, Faculty of Engineering
ERJ. Engineering Research Journal
1110-1180
2002-04-01
25
2
1
11
10.21608/erjm.2002.70637
70637
Original Article
MECHANICAL PROPERTIES OF SELF COMPACTING CONCRETE
A.G. Abdel-Rahman
1
Lecturer, Eng. Materials Dept., Faculty of Eng., Zagazig University, Zagazig, Ea"t.
Self-compacting concrete (SCC) is a new concept for fresh and hardened concrete and refers to the ability of fi-esh mixtures to deform and undergo change in shape and pass through obstacle under its own weight without exhibiting segregation and to ensure proper filling of the formwork. An experimental investigation was conducted to study the properties of hardened self-compacting concrete (SCC) and its bond strength. In this study, the hardened properties of (SCC) containing different sizes of coarse aggregate (20, 14 and 10 mm) were experimentally investigated and compared with those of conventional concrete. The effect of different dosage of viscosity 'enhanced admixture (VEA) (0,0.5, 1, 1.5 and 2% of cement weight) on the properties of hardened concrete are also discussed in this work. The mechanical properties of hardened self-compacting concrete (SCC) were investigated in terms of standard compressive strength and splitting tensile strength. Bond strengths were also determined for reinforcing bars embedded in concrete according to the Rilem test specification. Results from these tests show that higher size of coarse aggregate was found more suitable to ensure high compressive and tensile strength than corcrete made by smaller size of aggregate. A significant increase in bond strength was found when using higher size of coarse aggregate especially when comparing (SCC) to ordinary concrete. Also, higher values of compressive, tensile and bond strengths were obtained when using viscosity enhanced admixture (VEA) with a ratio of 1.5% of the cement weigh
https://erjm.journals.ekb.eg/article_70637_ab126ae89b62fcb428c8d99a6fb701ec.pdf
eng
Menoufia University, Faculty of Engineering
ERJ. Engineering Research Journal
1110-1180
2002-04-01
25
2
13
30
10.21608/erjm.2002.70640
70640
Original Article
NUMERICAL AND EXPERIMENTAL STUDY OF TURBULENT FLOW IN TWO DIMENSION INCLINED WALL JET
A. Abdel- Fattah
1
Lecturer in Mechanical Power Engineering Department, Faculty of Engineering, Menoufia University, Shebin El -Kom, Egypt. I ll
In the present study, a steady, two dimension turbulent isothermal and incompressible flow of inclined wall jet has been studied numerically and experimentally. The equations of momentum, continuity and the standard kr turbulent model are solved numerically using a finite-volume method to indicate the effects of wall inclination and Reynolds number on the flow characteristics of two-dimensional inclined wall jet. The Finite volume method is formulated to suite the general grid system. The numerical results indicate the effect of different values of wall angle (8 = 0°, 5O, go, 1 0°, 15O, 30' and 45') together with various Reynolds number (5x103, 10x103, 56x103, 86.24~10~ and 108.732~10~) onthevelocities (u, v), the pressure (p), the location of maximum velocity of flow (b,,/h) and the width of reciruclation zone (bmi,,/h). The present experimental work shows the wall static pressure at different values of wall angle (0°, 5', 8Oand 10') and different values of Re (56x lo3, 86.24~ lo3 and 108.732~ lo3). For the range of O0 5 8 5 45O, the results indicate that, when the wall angle increases, the maximum velocity decays faster and its location shifts towards free stream, while the jet spreads faster. The width of recirculation zone increases by increasing the wall angle and Reynolds number. The pressure increases by increasing the wall angle but this increment decays by increasing the Reynolds number. The numerical results give good agreement with the present experiment work and also with the experiment data of Ref. [I I].
https://erjm.journals.ekb.eg/article_70640_75b34cb3b16522bb2e5843f49ed39c47.pdf
General geometry
aerofoil designs
turbo-machinery
air condition
separation flow
eng
Menoufia University, Faculty of Engineering
ERJ. Engineering Research Journal
1110-1180
2002-04-01
25
2
31
42
10.21608/erjm.2002.70643
70643
Original Article
OPTIMAL REACTIVE POWER PLANNING USING GENETIC ALGORITHM
G. E. M. Aly
1
a. El-Desouki
2
Amany El-Zonkoly
3
Tmta University
Arab Academy for Science & Technology, Alex., Egypt
Arab Academy for Science & Technology, Alex., Egypt
This paper presents a new approach to solve the optimal reactive power planning (RPP) problem based on a genetic algorithm. The reactive power planning problem involves optimal placement and sizing of capacitors in a network such that the power loss cost and investment costs of new VAR sources are minimum. The genetic algorithm is a kind of search algorithm based on natural selection and genetics. This algorithm can search for global solution. The RPP problem is solved in two stages. The first stage determines the optimal placement of capacitors. The second stage determines the optimal sizing of such capacitors. The proposed approach incorporates detailed hourly loading conditions at each bus and achieves a fairly accurate estim k of the benefits from capacitor placement. The proposed method is applied to the IEEE 14-bus system and the IEEE 30-bus system and its results are compared with the results of a conventional method. Although this method is not as fast as sophisticated traditional methods, the applied concept is quite adequate for planning applications.
https://erjm.journals.ekb.eg/article_70643_2c93032aafbad86cfd18e769e9f75ace.pdf
Reactive power planing
Genetic Algorithm
Optimal power flow
eng
Menoufia University, Faculty of Engineering
ERJ. Engineering Research Journal
1110-1180
2002-04-01
25
2
43
58
10.21608/erjm.2002.70645
70645
Original Article
Numerical Simulation of Detonation Wave Damping Using a Layer of Granular Material
Ahmed A. Sileem
1
Dept. of Mech. Power Eng. Faculty of Eng., MinuJiya University, Shebin El-Kom, Egypt.
Damping or quenching of detonation wave is of great importance for safety of people, buildings, factories of chemical industries and equipment. In the present paper a layer of granular material is used to achieve this purpose. The main function of this layer is to absorb substantial part of both momentum and energy of the wave. Eventually, the detonation wave is extinguished and the pressure intensity is diminished. A model is given for drag force and heat transfer exchange between gas and solid particles. The detonation wave is initiated in a stoichiometric methane-air mixture at one end of a detonation tube. A layer of granular material is attached to the other closed end. The particles and the reactive mixture in the layer form a two-phase mixture that is initially at rest and in thermodynamic equilibrium. The dynamics in the entire domain following the collision of the propagating detonation front with the gasllayer interface is investigated. The void fraction of the granular layer is assumed constant (i.e. the particles velocity is zero). The chemical reaction is assumed to be one-step reaction of Arrhenius type. The unsteady governing equations in one-dimensional domair, are solved numerically. The effects of solid particle diameters, specific heat and the void fraction variations on detonation damping are found. The results show that considerable decay of detonation occurs immediately at the gadlayer interface. The decay continues along the layer until the wave is completely died out. The distance after which the wave dies out was found to decrease with the decrease of solid particles diameter and the void fraction and the increase of solid particles specific heat. The reflected shock wave (retonation) from the gasllayer interface propagates unsteadily backward and it is reflected from the closed end of the tube to strike the gadlayer interface again. The transmitted part of the latter wave dies out quickly inside the granular layer.
https://erjm.journals.ekb.eg/article_70645_7f7a122cb0faf4caf20a9a94289fc39f.pdf
Detonation waves damping
granular layer
two-phase flow of gas and solid particles
numerical solution
eng
Menoufia University, Faculty of Engineering
ERJ. Engineering Research Journal
1110-1180
2002-04-01
25
2
59
72
10.21608/erjm.2002.70648
70648
Original Article
Impact of Electrical Harmonics on The Efficiency of Energy Consumption of Air Conditioning Systems
Omar Basoudan
1
Yasser Hegazy
2
Riyadh College of Technology
Riyadh College of Technology
Harmonics injected to the power system by various equipments represent a burden on the system. The increase in the r.m.s current and therefore, the power consumption due to harmonics is one of its negative consequences. The identification of harmonic sources, the representation of the harmonics and the analysis of the behavior of the equipments with the existence of the harmonics show that a significant increase in these equipment consumption is due to the harmonics. The load distribution in Saudi Arabia has indicated that air conditioning consumes about 70% of the load in residential, commercial and governmental sectors. Therefore, the analysis of the impact of the harmonics on the energy consumption of air conditions can verify the benefit gained by increasing the efficiency of these systems with harmonic damping. This paper presents the results of the harmonic measurements conducted for different type of air conditions in nurnber of loads. It indicates an increase in the consumption of these system due to harmonics. The results show the degree of the harmonic level and therefore, the effect on the equipment efficiency.
https://erjm.journals.ekb.eg/article_70648_691d63bf7aa65931198f84beedc02eb8.pdf
eng
Menoufia University, Faculty of Engineering
ERJ. Engineering Research Journal
1110-1180
2002-04-01
25
2
73
91
10.21608/erjm.2002.70655
70655
Original Article
دراسة تحليلية لتأثير الاضاءة على التصميم المعماري للمتاحف
علاء الدين عبد الحيم قنديل
1
عاصم محمد الشاذلى
2
مدرس مساعد بکلية الهندسة جامعة المنوفية
أستاذ مساعد بکلية الهندسة جامعة المنوفية
https://erjm.journals.ekb.eg/article_70655_2b6889eba518e1de0afd43ac0e8e548e.pdf
eng
Menoufia University, Faculty of Engineering
ERJ. Engineering Research Journal
1110-1180
2002-04-01
25
2
93
101
10.21608/erjm.2002.70658
70658
Original Article
THE MOISTURE EFFECT ON THE INTERNAL STRAIN OF COMPOSITE INSULATION UNDER HIGH SLECTRIC FIELDS
Mohammad H. Abderrazzaq
1
Electrical Power Engineering Department, Hijjawi ]Faculty for Engineering Technology, Yarmouk University, Irbid-Jordan
This paper describes an investigation of the internal mechanical strain in composite samples with barriers cast midway between point-plain electrodes in a polyester resin. The paper also characterizes the dependence of this strain on the amount of moisture absorbed by the sample, especially under the influence of an applied electric field. In this work, the strain was studied for composite and homogeneous samples exposed to high electric fields in both wet and dry conditions. Through this study, the difference in the strain patterns between wet and dry samples is determined and the effect of moisture, as aging element reducing the adhesion strength between the barrier and the surrounding matrix, is highlighted.
https://erjm.journals.ekb.eg/article_70658_2e747d7d11e6cd6f6a7fb3bfc263fe74.pdf
eng
Menoufia University, Faculty of Engineering
ERJ. Engineering Research Journal
1110-1180
2002-04-01
25
2
103
117
10.21608/erjm.2002.70663
70663
Original Article
INFLUENCE OF ORTHOGONAL BURNISHING PARAMETERS ON SURFACE CHARACTERISTICS FOR VARIOUS MATERIALS
NI. H. El-AXIR
1
M. M. EL-KHABEERY
2
Assistant Professor Department of Production Engineering and Mechanical Design, Faculty of Engineering, Shebin El-kom, Egypt.
Associate Professor Department of Production Engineering and Mechanical Design, Faculty of Engineering, Shebin El-kom, Egypt.
Burnishing is used increasingly as a finishing operation which gives additional advantages such as increased hardness, fatigue strength, wear resistance. It is well known that burnished surface characteristic can significantly affect the resistance of components to failure when subjected to high cycle fatigue loads. The fatigue crack, in general, nucleates at the surface of the part, and then propagates into the-bulk. Consequently, it is the state of the surface characteristic, where the crack nucleates, that is of paramount importance. Experimental work was carried out on a lathe to establish the effect of four roller burnishing tool parameters; namely, burnishing speed, burnishing depth, burnishing time and the initial hardness of material on the surface microhardness, the out-of-roundness and the reduction in workpiece diameter. It was found that all input parameters have a controlling effect, with different percentage, on the three output responses. The results showed that burnishing depth and burnishing time are the most important parameters controlling the values of both out-of-roundness and reduction in workpiece diameter. Also, an increase in burnishing speed leads to a considerable reduction in the microhardness index. Out-of-roundness increases with a decrease in the initial hardness of workpiece material
https://erjm.journals.ekb.eg/article_70663_92608629e198f0f586deb89c86c4e116.pdf
eng
Menoufia University, Faculty of Engineering
ERJ. Engineering Research Journal
1110-1180
2002-04-01
25
2
119
126
10.21608/erjm.2002.70664
70664
Original Article
EXPERIMENTS WITH THE CARBONISING OF CAST IRON BY FLOATING METHOD
Stanislaw Borkowski
1
Technical University of Czestochowa, Department of Management, Division of Production Engineering, Czestoehowa, POLAND
This paper presents results from a range of floating grey cast iron tooling. Cast iron was floating in the chamber through a carbon carrying material - scrub of pipes or graphitization rods. This research involves the start crystallisation temperature (Tp) and temperatures like: TL, TSM, TS, graphitization constant (Kg), depth of clean hard spot (h,), surface of graphite separations and their number.
https://erjm.journals.ekb.eg/article_70664_e4e4ed085191bd6dbbb17b09d73d4a21.pdf
eng
Menoufia University, Faculty of Engineering
ERJ. Engineering Research Journal
1110-1180
2002-04-01
25
2
127
134
10.21608/erjm.2002.70760
70760
Original Article
THE COMPLEX TOOLING OF CAST IRON FOR LIGHT SECTION CASTINGS
Stanislaw Borkowski
1
Technical University of Czestochowa, Department of Management, Division of Production Engineering, Czestochowa, POLAND
This paper presents results, that were obtained after tooling white cast iron in industrial conditions, using the method of casting modifled with composite additions. The additions contained components which were more favourable, and also make prime graphitization difficult. It has reached shortening phase of cast iron graphitization, increase of R, and A5 tooled materials, as also reasonable lowering of fitted materials hardness. The obtained results were verified using a large slenderness ratio, which in connection with the change of liquid delivery method, it liquified on all lenghts of the microshrinkage and gave off prime carbon
https://erjm.journals.ekb.eg/article_70760_8cad9ec62429b070272b9d8940795cb2.pdf
eng
Menoufia University, Faculty of Engineering
ERJ. Engineering Research Journal
1110-1180
2002-04-01
25
2
135
145
10.21608/erjm.2002.70750
70750
Original Article
HIGH TEMPERATURE FATIGUE BEHAVIOR OF 7075A1 VIA LOW PLASTICITY BURNISHING
A. Abo El-Nasr
1
M. Ayad
2
M. Fattouh
3
Lecturer and ** Professor and Chairman Department of Production Engineering and Mechanical Design, Faculty of Engineering, Menoufiya University, Shebin El-Kom, Egypt
Lecturer and ** Professor and Chairman Department of Production Engineering and Mechanical Design, Faculty of Engineering, Menoufiya University, Shebin El-Kom, Egypt
Lecturer and ** Professor and Chairman Department of Production Engineering and Mechanical Design, Faculty of Engineering, Menoufiya University, Shebin El-Kom, Egypt
Rotating bending fatigue is considered to be an important characteristic of the mechanical parts. Herein, the high temperature fatigue behavior of 7075 aluminum is studied in terms of different mechanical and heat treatment procedures. These experiments were carried out in order to gain additional knowledge regarding the relationship between these processes and thefatigue behavior of the present alloy. A rotating bending test machine has been used to reach these goals. The fatigue experiments were performed under two different testing temperatures, 250 and 300 "C, along with the room temperature experiments. Low plasticity burnishing technique was applied on part of the specimens as a mechanical means for enhancing the fatigue strength of the present alloy. The results of the present work show that burnishing processes has played a considered role in increasing the fatigue strength of the present alloy. The enhanced fatigue resistance of the burnished specimens at high and room temperature was largely due to overall increase in the strength of the surface layer and delayed fatigue crack initiation on the surface.
https://erjm.journals.ekb.eg/article_70750_1efea96eb76e0c3c40e9ca670bfc27cf.pdf
High temperature fatigue
7075 Al
Low plasticity burnishing
Bending fatigue
Surface roughness
eng
Menoufia University, Faculty of Engineering
ERJ. Engineering Research Journal
1110-1180
2002-04-01
25
2
147
159
10.21608/erjm.2002.70751
70751
Original Article
Real-Time Harmonic Reduction using Synchronous PWM Control for Wound-Rotor Induction Motor
M. E. Abdel- Karirn
1
Electrical Power and Machines Dept., Faculty of Eng. Tanta University, EGYPT
In this paper the dynamic performance of the wound rotor induction motor operating with synchronized modulator is considered and analyzed. The proposed modulator employs a PWM transistor-controlled capacitive network in rotor circuit with a carrier fiequency proportional to the rotor voltage frequency. This modulator can reduce the harmonic current components of the motor and consequently improve the motor power factor. The reduction of these components is achieved instantaneously with no need for sensing or computing the harmonics current in motor current, thus simplifying the control system. Simulated and experimental results obtained from closed loop O.5KVA prototype confirm the feasibility and features of the proposed system.
https://erjm.journals.ekb.eg/article_70751_08e0d454609ef314fa8b6b0a6b040e1a.pdf
eng
Menoufia University, Faculty of Engineering
ERJ. Engineering Research Journal
1110-1180
2002-04-01
25
2
161
172
10.21608/erjm.2002.70753
70753
Original Article
Reactive and Harmonic Current Detection in a Nonlinear Load with Frequency Excursions
M. E. Abdel- Karim'
1
Electrical Power and Machines dept faculty eng Tanta University, EGYPT
In this paper, an effective estimator for detecting the reference current of active power filters and Var compensators is presented. The proposed estimator is adaptive and can be used with nonlinear loads under frequency excursions of the power source over a wide range. The effectiveness and accuracy of the proposed method are demonstrated and verified through ' the presented simulation and experimental results.
https://erjm.journals.ekb.eg/article_70753_b0a1eb760c2552dbceb86c318b904880.pdf
eng
Menoufia University, Faculty of Engineering
ERJ. Engineering Research Journal
1110-1180
2002-04-01
25
2
173
186
10.21608/erjm.2002.70757
70757
Original Article
AN EXPERIMENTAL STUDY OF ANNULAR DIFFUSER PERFORMANCE
Mofreh H. Hamed
1
Elsayed H. Farag.
2
Department of Mechanical Power Engineering, Faculty of Engineering, Menoufiya University, Shebin El-Kom, Egypt
Department of Mechanical Power Engineering, Faculty of Engineering, Menoufiya University, Shebin El-Kom, Egypt
The work described in this paper is concerned mainly with an experimental investigation of subsonic turbulent flows through annular diffusers having divergence angles of 17.5 and 9 degrees for the casing and hub, respectively, with an area ratio of 2.1. The performance of the tested diffuser was measured for a variety of throat dimensionless velocity (1) using different strut geometries. Two kinds of struts with airfoil and cylindrical cross-sections were installed separately at different locations inside the tested diffuser. The results indicated that, the magnitude of the dimensionless velocity (h) at the throat perimeter is dependent upon the strut cross-section and its location. The performance of the tested diffuser is improved when cylindrical struts with suitable diameters are set at an appropriate position in the diffuser. Increasing the blockage due to the presence of struts was found to be substantially increases the tendency of separation. The total loss coefficient due to nonuniformity of flow at the diffuser entrance was found to be significantly greater on the casing than that on the hub. It appeared also that, a better performance was achieved with the cylindrical struts due to the increase in turbulent mixing in the wake region.
https://erjm.journals.ekb.eg/article_70757_994b867bd46726e3ecff785beb16b873.pdf
eng
Menoufia University, Faculty of Engineering
ERJ. Engineering Research Journal
1110-1180
2002-04-01
25
2
187
199
10.21608/erjm.2002.70758
70758
Original Article
VALIDATION OF A FLEXIBLE CONTROLLER FOR A SUPERCONDUCTING GENERATOR
G. A. MORSY
1
Dept. of Elect.Eng., Faculty of Eng., Menoufya Univ., Egypt.
This paper describes an improved version of the H oo control schemes to enhance the performance and stability of the superconducting generator (SCG). A Flexible control structure is proposed, designed and implemented to overcome the problems that resulting from the low inherent damping nature of the superconducting generator. The controller is implemented using a detailed nonlinear simulation. The timeinvariant state space model is also obtained and the system oscillatory modes are given. The simulation results are represented in comparison with other results which obtained using conventional control systems. The linear time response simulation and the non-linear time response with the transient stability analysis confirms the superiority of the proposed controller and illustrate its effectiveness in system stabilization.
https://erjm.journals.ekb.eg/article_70758_05c89dbdfcf159f08136a6e3a3835a61.pdf