Open Access. Powered by Scholars. Published by Universities.®
- Discipline
-
- Chemical Engineering (9)
- Aerospace Engineering (6)
- Materials Science and Engineering (6)
- Mechanical Engineering (6)
- Structural Materials (6)
-
- Structures and Materials (6)
- Engineering Science and Materials (5)
- Mechanics of Materials (5)
- Engineering Mechanics (4)
- Transport Phenomena (4)
- Applied Mechanics (3)
- Catalysis and Reaction Engineering (2)
- Complex Fluids (2)
- Energy Systems (2)
- Computer Engineering (1)
- Computer-Aided Engineering and Design (1)
- Membrane Science (1)
- Keyword
-
- Orthogonal collocation (3)
- Catalyst particle (2)
- Finite element method (2)
- Frank-Kamenetskii equation (2)
- Laminates (2)
-
- Lane-Emden equation (2)
- Perturbation (2)
- Spherical annulus (2)
- Thermal explosion (2)
- : Prime numbers (1)
- ABAQUS; Aluminum alloys; Composite materials; Crystallography; Damage detection; Failure (mechanical); Laminated composites; Laminates; Laminating; Mechanisms; Nondestructive examination; Piezoelectric actuators; Piezoelectricity; Power quality; Structural analysis (1)
- Actuators and sensors; Computational technique; Finite element simulations; Finite element solution; Micro-mechanical modeling; Piezoelectric wafer active sensors; Symmetric laminated; Transformation field analysis (1)
- Approximate solutions (1)
- Averaging models (1)
- Bending (1)
- Bratu problem (1)
- Coal (1)
- Coating flow (1)
- Collocation (1)
- Composite numbers (1)
- Computational modeling (1)
- Cost analysis (1)
- Damage mechanics (1)
- Damage modes; Fibrous composites; Finite element models; Flexible Polyurethanes; Flying objects; Foam core; Modified designs; Structural failure; Wind towers; Wind turbine blades (1)
- Direct reduced iron (1)
- Dusty gas model (1)
- Dynamic loads; Energy dissipation; Exhibitions; Fatigue damage; Finite element method; Fracture mechanics; Turbomachine blades; Wind power; Wind turbines; Sandwich structures (1)
- Effectiveness factor (1)
- Electric arc furnace (1)
- Energy harvesting; Piezoelectric ceramics; Piezoelectricity; Textile fibers; Vibrations (mechanical) (1)
Articles 1 - 20 of 20
Full-Text Articles in Computational Engineering
One Formula For Non-Prime Numbers: Motivations And Characteristics, Kamal Hassan Prof., Mahmoud Mansour
One Formula For Non-Prime Numbers: Motivations And Characteristics, Kamal Hassan Prof., Mahmoud Mansour
Basic Science Engineering
Abstract: Primes are essential for computer encryption and cryptography, as they are fundamental units of whole numbers and are of the highest importance due to their mathematical qualities. However, identifying a pattern of primes is not easy. Thinking in a different way may get benefits, by considering the opposite side of the problem which means focusing on non-prime numbers. Recently, researchers introduced, the pattern of non-primes in two maximal sets while in this paper, non-primes are presented in one formula. Getting one-way formula for non-primes may pave the way for further applications based on the idea of primes.
A Reduced Model For Microbial Electrolysis Cells, Dina Aboelela, Moustafa A. Soliman, Ibrahim Ashour
A Reduced Model For Microbial Electrolysis Cells, Dina Aboelela, Moustafa A. Soliman, Ibrahim Ashour
Chemical Engineering
Microbial electrolysis cells (MECs) are breakthrough technology of cheap hydrogen production with high efficiency. In this paper differential-algebraic equation (DAE) model of a MEC with an algebraic constraint on current was studied, simulated and validated by implementing the model on continuous-flow MECs. Then sensitivity analysis for the system was effectuated. Parameters which have the predominating influence on the current density and hydrogen production rate were defined. This sensitivity analysis was utilized in modeling and validation of the batch-cycle of MEC. After that parameters which have less influence on MEC were eliminated and simplified reduced model was obtained and validated. Finally, …
A Reduced Model For Microbial Fuel Cell, Dina Aboelela, Moustafa A. Soliman, Ibrahim Ashour
A Reduced Model For Microbial Fuel Cell, Dina Aboelela, Moustafa A. Soliman, Ibrahim Ashour
Chemical Engineering
Microbial fuel cells (MFCs) are a group of microbial electrochemical cells (bioreactors) that are used to generate energy from organic waste found in wastewater. MFCs represent a promising method of waste disposal and production of electricity. Scaling up the use of MFCs requires extensive analysis and detailed grasp of the required processes. The current work aimed to study a model of an MFC, and find the optimum parameters needed for maximum energy production. The process was simulated and validated on continuous-flow MFCs with a Columbic efficiency of 162% and 35% COD removal. Sensitivity analysis of the model was performed. The …
Approximate Analytical Solution For Mathematical Models Of Thermal Ignition And Non-Isothermal Catalytic Zero Order Reaction In A Spherical Geometry, Moustafa A. Soliman
Approximate Analytical Solution For Mathematical Models Of Thermal Ignition And Non-Isothermal Catalytic Zero Order Reaction In A Spherical Geometry, Moustafa A. Soliman
Chemical Engineering
In this paper an approximate analytical solution for the Frank-Kamenetskii equation modeling thermal ignition without the depletion of the combustibles in a spherical annulus and non-isothermal zero order reaction in spherical catalyst particle is presented. The approximate solution is compared with the numerical solution and is in good agreement with the numerical solution. The approximate solution obtained is valid for all values of the distance parameter. Multiple solutions occur for some range of Frank-Kamenetskii parameter (λ). The multiplicity is infinite for the case of a solid sphere and λ=2.Interesting relation is obtained for λ at the turning points. For the …
Approximate Solution For The Lane-Emden Equation Of The Second Kind In A Spherical Annulus, Moustafa A. Soliman
Approximate Solution For The Lane-Emden Equation Of The Second Kind In A Spherical Annulus, Moustafa A. Soliman
Chemical Engineering
In this paper, we derive accurate approximate solution of Lane-Emden equation of the second kind in a spherical annulus geometry. The approximate solution is obtained by analytic arguments, and perturbation methods in terms of small and large radial distance parameter. The approximate solution is compared with the numerical solution. The approximate solution obtained is valid for all values of the radial distance parameter. Our best approximation has a maximum relative error in the dependent variable of 20%. In most cases it is much less than this value. This maximum error decreases as the radius of the annulus increases.
A Multiscale Model For Damage Progression And Detection In Piezo/Pyroelectric Composite Laminates, Yehia Bahei-El-Din, Amany Micheal
A Multiscale Model For Damage Progression And Detection In Piezo/Pyroelectric Composite Laminates, Yehia Bahei-El-Din, Amany Micheal
Centre for Advanced Materials
Assessment of damage initiation and progression in composite structures reinforced with electrically active filaments is modelled in a multiscale analysis. The analysis developed is a two-tier, interactive analysis, which involves two length scales; macroscopic, and microscopic. The proposed multiscale analysis provides seamless integration of the mechanics at the two length scales, including piezoelectric and pyroelectric coupling effects and damage under overall thermomechanical loads and an electric field applied to electroactive fibers. The macromechanical analysis is performed for multidirectional, fibrous laminates using the lamination theory, including bending, and the micromechanical analysis is performed using a two-phase model and a periodic array …
Detecting Laminate Damage Using Embedded Electrically Active Plies – An Analytical Approach, Amany Micheal, Yehia Bahei-El-Din
Detecting Laminate Damage Using Embedded Electrically Active Plies – An Analytical Approach, Amany Micheal, Yehia Bahei-El-Din
Centre for Advanced Materials
Assessment of damage initiation and progression in composite laminates with embedded electrically active plies is modeled. Utilizing electrically active layers embedded in composite laminates as damage sensors is proposed by several researchers and is mainly assessed experimentally. Sensing damage using embedded electrically active plies is generally preferred over the use of surface mounted PZT wafers since the range of the latter is limited to a very narrow area underneath the surface, while multiple damage mechanisms can generally be found in several plies of the laminate. The solution presented invokes two levels of analysis. Firstly, on the laminate level, applied membrane …
Finite Element Simulation Of Pzt-Aided Interrogation Of Composite Laminates Exhibiting Damage, Amany Micheal, Yehia Bahei-El-Din
Finite Element Simulation Of Pzt-Aided Interrogation Of Composite Laminates Exhibiting Damage, Amany Micheal, Yehia Bahei-El-Din
Centre for Advanced Materials
Piezoelectricity has proved effective in capturing changes in structures caused by various damage mechanisms. In one approach, piezoelectric wafer active sensors (PWAS) are mounted on the surface of the host structure and utilized as both actuators and sensors to interrogate the structure and monitor its health. This is achieved by subjecting the PWAS to a transient electric pulse and reading the resulting voltage. Changes in the stiffness of the substrate due to structural damage affect the response of the PWAS, which could be correlated to integrity of the structure. Applying this technique to fibrous composite laminates encounters particular challenges due …
Modelling Of Coal-Biomass Blends Gasification And Power Plant Revamp Alternatives In Egypt’S Natural Gas Sector, Dalia A. Ali Eng, Mamdouh A. Gadalla Prof., Omar Y. Abdelaziz, Fatma H. Ashour Prof.
Modelling Of Coal-Biomass Blends Gasification And Power Plant Revamp Alternatives In Egypt’S Natural Gas Sector, Dalia A. Ali Eng, Mamdouh A. Gadalla Prof., Omar Y. Abdelaziz, Fatma H. Ashour Prof.
Chemical Engineering
Recently, there has been a growing research interest in the co-gasification of biomass with coal to produce syngas and electricity in a sustainable manner. Co-gasification technology do not only decrease potentially the exploitation of a significant amount of conventional coal resources, and thus lower greenhouse gases (GHG) emissions, but also boost the overall gasification process efficiency. In the present work, a rigorous simulation model of an entrained flow gasifier is developed using the Aspen Plus® software environment. The proposed simulation model is tested for an American coal and the model validation is performed in good agreement with practical data. The …
A Multi-Scale Based Model For Composite Materials With Embedded Pzt Filaments For Energy Harvesting, A.E. El-Etriby, M.E. Abdel-Meguid, K.M. Shalan, Tarek Hatem, Yehia Bahei-El-Din
A Multi-Scale Based Model For Composite Materials With Embedded Pzt Filaments For Energy Harvesting, A.E. El-Etriby, M.E. Abdel-Meguid, K.M. Shalan, Tarek Hatem, Yehia Bahei-El-Din
Centre for Advanced Materials
Ambient vibrations are major source of wasted energy, exploiting properly such vibration can be converted to valuable energy and harvested to power up devices, i.e. electronic devices. Accordingly, energy harvesting using smart structures with active piezoelectric ceramics has gained wide interest over the past few years as a method for converting such wasted energy. This paper provides numerical and experimental analysis of piezoelectric fiber based composites for energy harvesting applications proposing a multi-scale modeling approach coupled with experimental verification. The multi-scale approach suggested predicting the behavior of piezoelectric fiber-based composites use micromechanical model based on Transformation Field Analysis (TFA) to …
Modeling Of Nitrogen Separation From Natural Gas Through Nanoporous Carbon Membranes, Moustafa A. Soliman, A A. Al-Rabiah, Abdelhamid M. Ajbar, F A. Almalki, Omar Y. Abdelaziz
Modeling Of Nitrogen Separation From Natural Gas Through Nanoporous Carbon Membranes, Moustafa A. Soliman, A A. Al-Rabiah, Abdelhamid M. Ajbar, F A. Almalki, Omar Y. Abdelaziz
Chemical Engineering
This work presents a theoretical investigation of the use of nanoporous carbon membranes for the separation of nitrogen from natural gas. A mathematical model to predict the performance of the membrane is developed. The model is a combination of the well known dusty gas model, which describes the transfer of multi-components mixture in porous media, together with a surface diffusion model. The model is first validated using the literature results for the separation of hydrogen from hydrocarbons mixture. The model is then applied to the nitrogen-hydrocarbons system. The membrane performance is evaluated in terms of nitrogen recovery, methane loss, nitrogen …
Approximate Analytical Solution For The Isothermal Lane-Emden Equation In A Spherical Geometry, Moustafa A. Soliman, Yousef S. Al-Zeghayer
Approximate Analytical Solution For The Isothermal Lane-Emden Equation In A Spherical Geometry, Moustafa A. Soliman, Yousef S. Al-Zeghayer
Chemical Engineering
This paper obtains an approximate analytical solution for the isothermal Lane-Emden equation that models a self-gravitating isothermal sphere. The approximate solution is obtained by perturbation methods in terms of small and large distance parameters. The approximate solution is compared with the numerical solution. The approximate solution obtained is valid for all values of the distance parameter.
Approximations To The Solution Of The Frank-Kamenetskii Equation In A Spherical Geometry, Moustafa A. Soliman
Approximations To The Solution Of The Frank-Kamenetskii Equation In A Spherical Geometry, Moustafa A. Soliman
Chemical Engineering
In this paper, an approximate analytical solution for Frank-Kamenetskii equation modeling a thermal explosion in a sphere, is obtained. The approximate solution is obtained by perturbation methods in terms of small and large distance parameter. The approximate solution is compared with the numerical solution obtained from an initial value problem formulation to the original boundary value problem. The approximate solution obtained is valid for all values of the distance parameter. For the original boundary value problem and for a given Frank-Kamenetskii parameter, a nonlinear algebraic equation needs to be solved to be able to apply the approximate solution.
Model-Based Energy Analysis Of An Integrated Midrex-Based Iron/Steel Plant, Abdelhamid M. Ajbar, Khalid I. Alhumaizi, Moustafa A. Soliman, Emadadeen Ali
Model-Based Energy Analysis Of An Integrated Midrex-Based Iron/Steel Plant, Abdelhamid M. Ajbar, Khalid I. Alhumaizi, Moustafa A. Soliman, Emadadeen Ali
Chemical Engineering
This article presents modeling and simulations of an integrated plant for the production of steel using the direct reduced iron (DRI)=electric arc furnace (EAF) route. In a previous work (Alhumaizi et al., 2012), a comprehensive mathematical model of an iron plant based on MIDREX technology was developed, validated, and simulated. In this article, the model is extended to account for an empirical model of an EAF plant. Numerical simulations were carried out for the effect of different operating parameters of the integrated plant. Useful profiles as well as a summary table were compiled to illustrate the results of the sensitivity …
A Modified Orthogonal Collocation Method For Reaction Diffusion Problems, Moustafa A. Soliman, Yousef S. Al-Zeghayer, Abdelhamid M. Ajbar
A Modified Orthogonal Collocation Method For Reaction Diffusion Problems, Moustafa A. Soliman, Yousef S. Al-Zeghayer, Abdelhamid M. Ajbar
Chemical Engineering
A low-order collocation method is often useful in revealing the main features such as concentration and temperature profiles and the effectiveness factor for porous catalyst particles. Two modifications are introduced in this paper to make the method more efficient. The first modification is to add an extra collocation point at the center of the particle. It is shown that such extra point introduces a single variable non-linear equation to be solved after obtaining the standard collocation method solution. In the second modification, the polynomial solution obtained from the application of the orthogonal collocation method is transformed to a rational function …
Efficient Numerical Scheme Of The Dynamics Of Nonisothermal Thin Film Flow, Moustafa A. Soliman, Khalid I. Alhumaizi
Efficient Numerical Scheme Of The Dynamics Of Nonisothermal Thin Film Flow, Moustafa A. Soliman, Khalid I. Alhumaizi
Chemical Engineering
In this work we use Lubrication type method, based on the possibility of the separation of longitudinal and transversal length scales to simplify the analysis of thin film dynamics. We study the dynamics of evaporating thin liquid films on an inclined plane, where the effect of van der Waal forces is significant. The numerical solution of the evolution equation is carried out using the method of orthogonal collocation and is used for the study of the instabilities of evaporating thin film to identify conditions for efficient operation. For symmetric cases where the plane is horizontal, a two spline collocation second …
Dynamics Of A Coating Film Flow On Horizontal Cylinders With Van Der Waals Forces, Moustafa A. Soliman, Khalid I. Alhumaizi
Dynamics Of A Coating Film Flow On Horizontal Cylinders With Van Der Waals Forces, Moustafa A. Soliman, Khalid I. Alhumaizi
Chemical Engineering
In this work we use the lubrication type method, based on the possibility of the separation of longitudinal and transversal length scales, to simplify the analysis of coating film dynamics. We study the dynamics of coating thin films on horizontal stationary and rotating cylinders in general, and when the effect of van der Waals forces is significant. A computer code based on the method of orthogonal collocation is developed and is used for the study of the instabilities of coating thin film flow on cylinders to identify conditions of stable operation. For stationary cylinders, the equations are symmetric and the …
Rational Approximation For The One-Dimensional Bratu Equation, Moustafa A. Soliman
Rational Approximation For The One-Dimensional Bratu Equation, Moustafa A. Soliman
Chemical Engineering
The solution of the one dimensional planar Bratu equation is characterized by having two branches. The two branches meet at a limit point that can be obtained through the solution of an eigen-relation. In this paper a transformation is introduced to transform this highly non-linear problem to a linear one. Rational expressions are given for the solution of the Bratu equation and the limit point. This is done using collocation and perturbation techniques.
Multiscale Transformation Field Analysis Of Progressive Damage In Fibrous Laminates, Yehia Bahei-El-Din, Ritesh Khire, Prabhat Hajela
Multiscale Transformation Field Analysis Of Progressive Damage In Fibrous Laminates, Yehia Bahei-El-Din, Ritesh Khire, Prabhat Hajela
Centre for Advanced Materials
As part of an ongoing effort to model uncertainty propagation across multiple scales in fibrous laminates, this paper presents a deterministic transformation field analysis for modeling damage progression under membrane forces and bending moments. In this approach, equivalent eigenstresses are computed in the phases and/or plies such that their respective stress components that satisfy the underlying failure criteria are reduced to zero. Superposition of the solutions found for the undamaged laminate under applied loads and under the eigenstress field provide the entire response. Failure criteria are based on stress averages in the fiber and matrix. Damage mechanisms considered are frictional …
Modified Sandwich Structures For Improved Impact Resistance Of Wind Turbine Blades, Yehia Bahei-El-Din, Mostafa Shazly, I. El-Habbal, Y. Elbahy
Modified Sandwich Structures For Improved Impact Resistance Of Wind Turbine Blades, Yehia Bahei-El-Din, Mostafa Shazly, I. El-Habbal, Y. Elbahy
Centre for Advanced Materials
Wind turbine blades are susceptible to damage due to fatigue as well as impact by flying objects and parts broken off failed blades of nearby wind towers. Localized, permanent compression of the foam core and delamination of the fibrous composite face sheets are typical damage modes and can lead to progressive structural failure. Sandwich structures modified by inclusion of flexible polyurethane (PU) layers within the cross section are examined under both impact and dynamic loads. Finite element models of sandwich structures with conventional and modified designs show that sandwich designs modified with PU interlayes exhibit reduced foam core crushing and …