Documents published in Scipedia

• Experimental and numerical simulation of scour at bridge abutment provided with different arrangements of collars

  T. Nasr-Allah, Y. Moussa, G. Abdel-Aal, A. Awad

  Collection of Alexandria Engineering Journal (2017).

  
  

  Abstract

  In this paper, the effects of different widths and lengths of collar around bridge abutment on local scour depth are studied numerically and experimentally. Numerical simulation of scour hole evolution at bridge abutment is more convenient than the experimental modeling, because the computational cost and time have significantly decreased. The numerical model solves 3-D Navier–Stokes equations and bed load conservation equation. The k–ε turbulence model is used to solve the Reynolds-stress term. The simulated results are verified using the laboratory experiments. In addition, the multiple linear regressions are applied to correlate the maximum local scour depth with the other independent parameters. It was found that the relative length of collar 0.73 around bridge abutment reduces the maximum scour depth by 69% compared to no-collar case. Moreover, the results of 3-D numerical model and regression models agree well with the experimental data.

  Abstract
  In this paper, the effects of different widths and lengths of collar around bridge abutment on local scour depth are studied numerically and experimentally. Numerical simulation [...]

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• Differential Transformation Method for Newtonian and non-Newtonian nanofluids flow analysis: Compared to numerical solution

  M. Hatami, D. Jing

  Collection of Alexandria Engineering Journal (2017).

  
  

  Abstract

  In this study, a simple and high accurate series-based method called Differential Transformation Method (DTM) is used for solving the coupled nonlinear differential equations in fluids mechanic problems. The concept of the DTM is briefly introduced, and its application on two different cases, natural convection of a non-Newtonian nanofluid between two vertical plates and Newtonian nanofluid flow between two horizontal plates, has been studied. DTM results are compared with those obtained by a numerical solution (Fourth-order Runge–Kutta) to show the accuracy of the proposed method. Results reveal that DTM is very effective and convenient which can achieve more reliable results compared to other analytical methods in solving some engineering and sciences problems.

  Abstract
  In this study, a simple and high accurate series-based method called Differential Transformation Method (DTM) is used for solving the coupled nonlinear differential equations [...]

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• Exact solutions to the (3+1)-dimensional coupled Klein–Gordon–Zakharov equation using exp(−Φ(ξ))-expansion method

  M. Hafez

  Collection of Alexandria Engineering Journal (2017).

  
  

  Abstract

  In this article, the exp(-Φ(ξ))exp(-Φ(ξ))-expansion method is modified for (3+1)-dimensional space–time coordinate system and successfully implemented to construct the new exact traveling wave solutions of the (3+1)-dimensional coupled Klein–Gordon–Zakharov equation. The solutions of this equation are expressed in terms of hyperbolic, trigonometric, exponential and rational functions. The results illustrate its effectiveness for solving nonlinear coupled partial differential equations arises in mathematical physics and engineering. The annihilation phenomena of the wave propagation in the xx–yy plane are also investigated. Furthermore, the three-dimensional surface plots due to the obtained solutions are also given to make the dynamics of the equation visible.

  Abstract
  In this article, the exp(-Φ(ξ))exp(-Φ(ξ))-expansion method is modified for (3+1)-dimensional space–time coordinate system and successfully implemented to construct the [...]

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• An investigation into sound transmission loss by polypropylene needle-punched nonwovens

  K. Ghorbani, H. Hasani, M. Zarrebini, R. Saghafi

  Collection of Alexandria Engineering Journal (2017).

  
  

  Abstract

  In this work, the effects of variables such as initial carded web mass, needle penetration depth, punch density, and the frequency of incident sound wave on transmission of sound through polypropylene needle-punched nonwovens were investigated. Fibrous carded webs using commercially available 17 dtex, 90 mm staple length polypropylene fibers were prepared with different mass per unit area using carding machine. Samples were needled at various punch-densities and needle penetration depths were produced. Design points of experiments were set up using Taguchi experimental design method. Sound transmission loss (STL) of needled samples was measured using an impedance tube equipped with four microphones. Minitab software was used to analyze the sound transmission ability of the samples. Results indicated that all of the considered controllable factor have significant effects on STL values determined for the needled nonwovens. Also, initial carded web mass was found to be the most influential factor affecting sound transmission through the samples. It was concluded that an increase in thickness of the samples as well as mass per unit area of nonwovens results in higher sound transmission loss by the samples.

  Abstract
  In this work, the effects of variables such as initial carded web mass, needle penetration depth, punch density, and the frequency of incident sound wave on transmission of [...]

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• Efficient design of exhaust gas cooler in cold EGR equipped diesel engine

  N. Ghassembaglou, L. Torkaman

  Collection of Alexandria Engineering Journal (2017).

  
  

  Abstract

  Using cold EGR method with variable venturi and turbocharger has very significant effect, simultaneously on the reduction of NOX and grime simultaneously. EGR cooler is one of the most important parts in the cold EGR circuit. In this paper optimum design of cooler for working in different percentages of EGR, besides determination of optimum temperature of exhausted gases, efficiency growth, weight reduction, dimension and expenditures reduction, sediment reduction, and optimum performance by using gasoil which has significant amounts of brimstone, is investigated and optimized.

  Abstract
  Using cold EGR method with variable venturi and turbocharger has very significant effect, simultaneously on the reduction of NOX and grime simultaneously. EGR cooler is one [...]

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• Delay compensation using Smith predictor for wireless network control system

  M. Gamal, N. Sadek, M. Rizk, A. Abou-elSaoud

  Collection of Alexandria Engineering Journal (2017).

  
  

  Abstract

  Wireless Sensor Network (WSN) is widely used in the industrial Network Control System (NCS). It relies on the IEEE 802.15.4 MAC protocol to transfer data at low rate. Experimental and theoretical studies proved that the wireless channel produces a time delay. In the NCS, this delay may cause system instability and performance degradation. Delay compensation schemes are used to reduce the delay effects. In this paper, a delay compensation scheme using classical and adaptive Smith predictor is applied to wireless NCS. The Markov model is proposed to compute the estimated network delay used in the classical predictor. In the adaptive predictor, the channel delay statistics using shift register is proposed to update the estimated delay. To evaluate the proposed schemes, a DC-motor controller system based on IEEE 802.15.4 is built using True Time Matlab software. The system performance with and without the proposed delay compensation scheme is studied. It is also compared to other delay compensation schemes. The results show that the proposed scheme improves the NCS performance significantly and reduces the effect of the delay on the system.

  Abstract
  Wireless Sensor Network (WSN) is widely used in the industrial Network Control System (NCS). It relies on the IEEE 802.15.4 MAC protocol to transfer data at low rate. Experimental [...]

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• Electrospun polymethylacrylate nanofibers membranes for quasi-solid-state dye sensitized solar cells

  M. Fathy, A. Kashyout, J. Nady, S. Ebrahim, M. Soliman

  Collection of Alexandria Engineering Journal (2017).

  
  

  Abstract

  Polymethylacrylate (PMA) nanofibers membranes are fabricated by electrospinning technique and applied to the polymer matrix in quasi-solid-state electrolytes for dye sensitized solar cells (DSSCs). There is no previous studies reporting the production of PMA nanofibers. The electrospinning parameters such as polymer concentration, applied voltage, feed rate, tip to collector distance and solvent were optimized. Electrospun PMA fibrous membrane with average fiber diameter of 350 nm was prepared from a 10 wt% solution of PMA in a mixture of acetone/N, N-dimethylacetamide (6:4 v/v) at an applied voltage of 20 kV. It was then activated by immersing it in 0.5 M LiI, 0.05 M I2, and 0.5 M 4-tert-butylpyridine in 3-methoxyproponitrile to obtain the corresponding membrane electrolyte with an ionic conductivity of 2.4 × 10−3 S cm−1 at 25 °C. Dye sensitized solar cells (DSSCs) employing the quasi solid-state electrolyte have an open-circuit voltage (Voc) of 0.65 V and a short circuit current (Jsc) of 6.5 mA cm−2 and photoelectric energy conversion efficiency (η) of 1.4% at an incident light intensity of 100 mW cm−2.

  Abstract
  Polymethylacrylate (PMA) nanofibers membranes are fabricated by electrospinning technique and applied to the polymer matrix in quasi-solid-state electrolytes for dye sensitized [...]

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• Computer applications in railway operation

  M. Aly, H. Hemeda, M. El-sayed

  Collection of Alexandria Engineering Journal (2017).

  
  

  Abstract

  One of the main goals of the railway simulation technique is the formation of a model that can be easily tested for any desired changes and modifications in infrastructure, control system, or in train operations in order to improve the network operation and its productivity. RailSys3.0 is a German railway simulation program that deals with this goal. In this paper, a railway network operation, with different suggested modifications in infrastructure, rolling stocks, and control system, using RailSys3.0, has been studied, optimized, and evaluated. The proposed simulation program (RailSys 3.0) was applied on ABO-KIR railway line in Alexandria city, as a case study, to assess the impact of changing track configuration, operating and control systems on the performance measures, time-table, track capacity and productivity. Simulation input, such as track element, train and operation components of the ABO-KIR railway line, has been entered to the computer program to construct the simulation model. The simulation process has been carried out for the existing operation system to construct a graphical model of the case-study track including line alignment and train movements, as well as to evaluate the existing operation system. To improve the operation system of the railway line, eight different innovative alternatives are generated, analyzed and evaluated. Finally, different track measures to improve the operation system of the ABO-KIR railway line have been introduced.

  Abstract
  One of the main goals of the railway simulation technique is the formation of a model that can be easily tested for any desired changes and modifications in infrastructure, [...]

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• Wind-induced loads and integrity assessment of hyperboloid reflector of solar power plants

  M. Eswaran, R. Verma, G. Reddy

  Collection of Alexandria Engineering Journal (2017).

  
  

  Abstract

  Flow-induced loads and Strouhal frequencies of secondary hyperboloid reflector which is located at top of the central tower of a proposed solar power plant are investigated. Initially for validation, flow-induced vibration characteristics of 3-D rectangular cylinder are studied and found in good agreement with previously published results. After the validation of the present numerical procedure, the force coefficients and the Strouhal frequencies of solar secondary hyperboloid reflector are determined for operational and survival wind speeds. Influences of various numerical parameters are investigated through the statistical values of the drag and the lift coefficients, Strouhal number, and pressure distribution. Finite element analysis has also been done to find out the deflections and stresses due to dead weight, imposed loads and wind loads and to optimize the design of hyperboloid and towers.

  Abstract
  Flow-induced loads and Strouhal frequencies of secondary hyperboloid reflector which is located at top of the central tower of a proposed solar power plant are investigated. [...]

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• Foundation analyzing of centrifugal ID fans in cement plants

  H. Eskandari, M. Nik, A. Pakzad

  Collection of Alexandria Engineering Journal (2017).

  
  

  Abstract

  This research was based on a finite-element model (FEM) of large foundations such as induced draft (ID) fans. Three-dimensional (3D) linear analyses were performed under arbitrary static and dynamic loads for various modulus of elasticity of concrete (Ec) (20, 25, 28 and 30 GPa) and reinforcement (Es) (200, 250, 300 GPa). FEM results were compared with the existing ID fan foundations (laboratory-based evidence) to assess the accuracy of simulations made by the FEM. This study validated what constitutes a major departure from current thinking regarding material properties modeling of concrete under various loads to increase foundation for lifetime.

  Abstract
  This research was based on a finite-element model (FEM) of large foundations such as induced draft (ID) fans. Three-dimensional (3D) linear analyses were performed under arbitrary [...]

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