2024-03-28T11:16:11Z
https://erjm.journals.ekb.eg/?_action=export&rf=summon&issue=10163
ERJ. Engineering Research Journal
1110-1180
1110-1180
2011
34
2
A PARTICLE SWARM-AIDED APPROACH FOR STABILITY ENHANCEMENT OF A SUPERCONDUCTING GENERATOR USING AN SVC-BASED STABILIZER
R. A. F.
Saleh
An important aspect in developing superconducting generator (SCG) concerns stability following a major system disturbance. This paper presents a method for enhancing stability of a SCG connected to an infinite-bus system using one of FACTS devices. In this method, a static VAR compensator (SVC)-based stabilizer is designed in coordination with a governor controller (GC) to effectively damp the mechanical oscillations which arise in the system when subjected to a disturbance. A time response-based objective function is defined and the design problem of SVC-based stabilizer and GC is formulated into an optimization problem. Particle swarm optimization (PSO) technique is employed to find out an optimal set of parameters for SVC-based stabilizer and GC. Simulation results, damping torque analysis, and small signal analysis show that the proposed PSO-based control scheme provides more damping to the SCG, and enhances its stability over a range of operating conditions.
Superconducting generator
Transient stability
FACTS
Particle Swarm Optimization
2011
04
01
103
110
https://erjm.journals.ekb.eg/article_67261_35df9edb72f505715604e5e516fbcedb.pdf
ERJ. Engineering Research Journal
1110-1180
1110-1180
2011
34
2
AVERAGE CHARACTERISTICS OF CYLINDRICAL STATOR 6/2 SWITCHED RELUCTANCE GENERATOR
F. M.
El-Kholy
A. F.
Abdel-Kader
The switched reluctance motor can be used in generation mode by selecting the firing angles of the phases current. Switched reluctance generators (SRG) have been identified as a potential option for military aircraft, variable speed wind turbine and automotive electric power systems. (SRG) has various desirable features which include simple and solid structure, easiness of maintenance, small moment of rotor inertia and low cost.
This paper presents detailed average characteristics of a 6/2 cylindrical stator (SRG). The suitable control for maximum energy conversion in SRG is obtained. The excitation converter is arranged for continuity of load phases current. The results are computed from the average analysis equations.
Maximization of power throughout of (SRG) has been addressed in this paper. Phase self-inductance, phase voltage switching angles, DC bus voltage level and shaft speed of the generator have been identified as generator parameters and control variables affecting output power. Depending on the application each one of these parameters can be defined as either generator parameter or control variable. Due to highly nonlinear characteristics of (SRG), the analytical equation for output power in terms of generator parameters and control variables is complicated. So, iterative simulation of the generator model on the range of generator parameters and control variables has been used for finding output power profile.
Reluctance generator
Generator control
Wind energy generator
Aircraft generator
Automotive generator
Variable speed generator
2011
04
01
111
117
https://erjm.journals.ekb.eg/article_67262_616d07538558215f68a38e3d321334c3.pdf
ERJ. Engineering Research Journal
1110-1180
1110-1180
2011
34
2
INDIRECT FIELD-ORIENTED CONTROL OF FIVE-PHASE INDUCTION MOTOR DRIVES
Z. M. S.
Elbarbary
S. A.
Mahmoud
This paper proposes an indirect field oriented controller for five-phase induction motor drives. The controller is based on indirect vector control technique. Simulation is carried out by using the Matlab/Simulink package. The performance of the proposed system is investigated at different operating conditions. The proposed controller is robust and suitable for high performance five-phase induction motor drives. Simulation results validate the proposed approaches.
Five-Phase Induction motor
five-phase Inverter
2011
04
01
119
123
https://erjm.journals.ekb.eg/article_67263_df53974a103043c97110e91416a615f4.pdf
ERJ. Engineering Research Journal
1110-1180
1110-1180
2011
34
2
PREDICTIVE CONTROL OF MULTI-LEVEL INVERTER FED THREE-PHASE INDUCTION MOTOR
M.
El Saidy
F.
El-Khouly
S. S.
Shokralaa
This paper presents a predictive control for multi-level inverter drive induction motor. Implementations of the control algorithm as well as, the multi-level inverter are presented. Also, the system is simulated and the speed, voltage, and current of an induction motor under normal and up-normal performance are obtained. The system is tested under a wide range of reference speed changes as well as different load conditions. Several simulation results using Matlab simulink software show the validity of the predictive control and multi level inverter scheme.
2011
04
01
125
133
https://erjm.journals.ekb.eg/article_67264_62c5c793c296eb30be3226bc0bd9765d.pdf
ERJ. Engineering Research Journal
1110-1180
1110-1180
2011
34
2
INFLUENCE OF COAXIAL SWIRLING LIQUID FLOW ON INTERNAL MIXING AIR-ASSISTED ATOMIZER
M. A. O.
Shehata
A.
Abd Elmotalip
The present work is devoted experimentally to determine the behavior of the flow of both air and water in an internal mixing air-assisted atomizer with swirling coaxial liquid, pointing the attention on the optimization of some geometrical parameters. Some experiments have been performed for air central channel diameter and coaxial liquid port, as well as for several experimental conditions (air and water pressures), this is an important result that will help in the optimum design of this type of atomizer.
2011
04
01
149
153
https://erjm.journals.ekb.eg/article_67266_a242f0b8044b58de2b466c07c5d8f8ab.pdf
ERJ. Engineering Research Journal
1110-1180
1110-1180
2011
34
2
AN AGENT-BASED IMAGE DESCRIPTION FRAMEWORK
Tarek
Helmy
Ahmed
Al-Nazer
This paper presents high quality graphical computer software that helps the visually impaired people to interact with the graphical computer software. We note that almost every document contains some kind of images which make a problem for special users like visually impaired people to interact and understand the context of the document. As we know that there is a support for text to be converted into voices but there exist no support for an image to be converted into a voice. This issue has motivated us to develop a framework that can give a text description of the images, where its real description significantly aids the work of both visually impaired and professionals. Based on this idea, we have developed an Agent-based Image Description Framework (ABIDF) that enables visually impaired people to recognize most common geometrical shapes in addition to some normal images. The framework produces phrases to describe the recognized shapes, and finally submits the generated text description to the voice synthesizer to be converted into speeches. This process will help the visually impaired users to identify these charts and make the required information more available to them. To support the usefulness of our work, experimental applications are introduced and the obtained converted images into voices showed successful and encouraging results of the proposed framework.
Human Computer Interaction
Multi-Agent
Image Description
2011
04
01
135
148
https://erjm.journals.ekb.eg/article_67267_84d426d5afc26249c499081e2319f869.pdf
ERJ. Engineering Research Journal
1110-1180
1110-1180
2011
34
2
AN INVESTIGATION OF THE CONTROLLING METHODS FOR THE SECONDARY LOSSES IN TURBINE BLADES
A. M .
Alam El-Din
I. A .
El-Sawaf
A. A.
El-Abady
Y. K.
Hassan
Secondary flow remains a challenging task for both the researchers who pursue diligently their efforts to develop an improved understanding of the mechanisms of loss production and for the designers who endeavor to minimize the impact of losses on turbine performance by controlling the secondary flow and by reducing their interference with the main flow. As an extension to control secondary flows and losses reduction in turbine blades, this work introduces an experimental investigation which was carried out to establish the effect of endwall injected air on a turbine blade losses by different air jets location through flow channel between two consecutives blades and also with different inlet air flow speed at subsonic flow conditions through the blade cascade. Tests were conducted by using a linear cascade of turbine blades. The cascade was fixed on a wind tunnel and working as air flow supply. Measurements of wall static pressure on the pressure and suction sides of the blades, the total pressure at flow passage exit section and determination of flow loss for blade profiles are presented. The results showed readings changes due to the alteration of location and speed of endwall air jets. It is found that, the best results were recorded in the case of endwall air jets location at suction side of the tested blade with M = 0.12. Air jets successfully diverts the path of the passage vortex and decreases its effect on the suction side blade by creating higher static pressure on pressure side (10.2% higher in blade pressure loading than on case without air injection application) and preventing boundary layer separation at suction side and also This modification has a significant effect to create a homogeneous pressure distribution through blade chordwise and hence reducing the possibilities of flow vortices existence then reducing the undesirable effects of secondary flow.
Secondary losses
Turbine blades
Air injection
Pressure distribution
Boundary layer separation
Endwall jets
Passage Vortex and Blade loading
2011
04
01
155
165
https://erjm.journals.ekb.eg/article_67268_cb19467e774eda562d325c6eb7a7be02.pdf
ERJ. Engineering Research Journal
1110-1180
1110-1180
2011
34
2
ASSESSING THE RISK OF THE ASWAN HIGH DAM BREACHING
Fahmy S.
Abdel-Haleem
Y. Esam
Helal
A.
El-Belasy
S.A.
Ibrahim
M.F.
Sobeih
The present paper assesses the risk of the Aswan High Dam breaching, numerically. Literature, in the field of dam breaching, was reviewed. The Aswan High Dam was visited. Site data, so as measurements data, were collected and analyzed. A suitable numerical model was chosen and was selected to be implemented. Scenarios were designed. The expected impacts of the Aswan High Dam failure that might result from overtopping or piping was simulated and the obtained results were analyzed. Outflow hydrographs due to the failure mode were obtained and analyzed. A risk assessment to the dam breaching was achieved. The results of this investigation could be further applied and could assist decision makers to set a plan to confront the risks of the Aswan High Dam failure.
Dam Breach
Outflow hydrograph
Aswan High Dam
Simulation Model
2011
04
01
167
179
https://erjm.journals.ekb.eg/article_67269_24b021bed480fec68648d89b13165361.pdf
ERJ. Engineering Research Journal
1110-1180
1110-1180
2011
34
2
FABRICATION AND CHARACTERIZATION OF ALUMINUM- GRAPHITE COMPOSITES
A.I.
Selmy
F.
Shehata
A.
Fathy
E.
Gewfiel
In the present study, a proposed technique called “ex-situ and in-situ powder metallurgy” has been developed to produce aluminum–graphite (Al/Gr) composites. In order to avoid any interfacial reactions between the graphite and the aluminum, an isostatic pressing of material powders followed by hot extrusion techniques was used. Five weight percentages of graphite flakes were mixed with Al powder using a mechanical mixing stirrer. The thermal characteristics and microstructures of the composite were investigated. The effects of graphite content and SiC formation on structure characteristics and properties of composites were investigated. The results showed that some graphite flakes have reacted with silicon present in commercial aluminum powder and formed silicon carbide (SiC) at temperatures above 252 ◦C. SiC has great effect on composite characteristics. The results also showed refinement and uniform distribution of graphite and SiC particles within the aluminum matrix.
Composite
graphite flakes
cold pressing
hot extrusion
Tensile Properties
2011
04
01
181
187
https://erjm.journals.ekb.eg/article_67270_ebb6d904d65684e75dec0a743b2ae5c4.pdf
ERJ. Engineering Research Journal
1110-1180
1110-1180
2011
34
2
MANUFACTURING AND MECHANICAL BEHAVIOR OF THE GRAPHITE NANOPLATELETS / Al MATRIX COMPOSITES
A.I.
Selmy
F.
Shehata
E.
Gewfiel
One of the main objectives of this work is to manufacture the reinforcing graphite nanoplatelets (CNPLs)] materials in the laboratory from the natural graphite. Also, aluminum matrix composite reinforced with 1, 2, 3, 4 and 5 wt.% graphite nanoplatelets has been fabricated by cold pressing, followed by hot extrusion techniques. Scanning electron microscopy (SEM) has been used to examine the dispersion of CNPLs and aluminum, and to analyze the composites structure. The microstructure characteristics and the distribution of CNPLs in the aluminum matrix were investigated. The mechanical properties of the composites were recorded at room temperature. Experimental results showed that CNPLs were distributed homogeneously in the (CNPLs/Al) composites. The CNPLs content affects significantly on the mechanical properties of (CNPLs/Al) composites. Meanwhile, the 2.0 wt.% CNPLs /Al composite is found to exhibit the highest hardness, yield and ultimate tensile strengths. Also, it is noticed that the elongation percentages remain nearly constant. The extraordinary mechanical properties (yield and ultimate tensile strengths) of CNPLs may be the reason for this increments, in additional to the bridging and pulling-out role of CNPLs in the aluminum matrix composites. The tightly bonded interface between the matrix and CNPLs can also effectively transfer the load to the graphite nanoplatelets. Further enhanced strength has been achieved by reinforcing the matrix with dispersed nanoplatelets in such composites.
Composite
graphite nanoplatelets
cold press
hot extrusion
Mechanical Properties
2011
04
01
189
195
https://erjm.journals.ekb.eg/article_67271_34944b8e23c6733af36315cd71484681.pdf
ERJ. Engineering Research Journal
1110-1180
1110-1180
2011
34
2
AN AGGREGATE PRODUCTION PLANNING MODEL FOR PAINT INDUSTRY IN FUZZY ENVIRONMENT
M. N.
Fors
A.
Eldomiaty
M. A.
Zaghloul
S. A.
Elsanabary
This work presents Aggregate Production planning (APP) in fuzzy environment for paint industry. In real-world APP problems, input data or parameters, such as demand, resources, costs are fuzzy / imprecise in nature because some information is incomplete or unobtainable. This study applying Possibilistic Linear Programming (PLP) to solve multi- product and multi- period APP problem with fuzzy / imprecise objective and cost coefficients by triangular possibility distributions under uncertainty. The APP model designed to minimize total production costs, while considering inventory level, labor levels, and machine capacity. The model provides a systematic framework that help decision- making to solve APP problems under fuzzy environment, and help decision maker (DM) to modify the the data until a set of satisfactory solution is obtain.
Aggregate production planning
Fuzzy Environment
Possibilistic linear Programming
2011
04
01
197
203
https://erjm.journals.ekb.eg/article_67272_c034837d4f79894c243d992911ad861d.pdf
ERJ. Engineering Research Journal
1110-1180
1110-1180
2011
34
2
EFFECT OF TOOL GEOMETRY AND WELDING PARAMETERS ON THE MECHANICAL PROPERTIES OF COMMERCIAL ALUMINUM WELD JOINTS BY FRICTION STIR WELDING
M. A.
Shaker
A.
El Baghdady
S.
Misbah
In the present study, mechanical properties of friction-stir-welded pure Al with varying welding parameters, including rotating and welding speeds, were examined. Five-mm-thick pure Al plates were FSW with varying tool rotating speeds of 600, 800, and 1200 rpm, and welding speeds of 40, 60, 80 mm/min. Different tool pin profiles (three shapes) were developed to weld the Specimens and the effect of tool pin profile on the mechanical properties of the weld joints was studied. Tensile test specimens were prepared with the tensile direction perpendicular to the welding direction, so that the weld zone was located in the middle of the specimen. The yield and ultimate tensile strengths were affected, by welding and rotational speeds but to a significantly less degree, with varying welding parameters. Low welding speed or high rotating speed tended to encourage the plastic flow per unit time and consequently the clustering of coarse precipitates. The hardness of the specimens was affected also by the different welding parameters. The effect of pin cross section on mechanical properties was analyzed and it was found that joints welded with straight cylinder pin cross section had better mechanical properties compared to the other pin cross sections .
Friction Stir Welding
Mechanical Properties
Macrostructure
2011
04
01
205
214
https://erjm.journals.ekb.eg/article_67273_b34d4d93ced009522c5b743850350364.pdf