International Journal of Mechanics

  
ISSN: 1998-4448
Volume 14, 2020

Notice: As of 2014 and for the forthcoming years, the publication frequency/periodicity of NAUN Journals is adapted to the 'continuously updated' model. What this means is that instead of being separated into issues, new papers will be added on a continuous basis, allowing a more regular flow and shorter publication times. The papers will appear in reverse order, therefore the most recent one will be on top.

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Volume 14, 2020


Title of the Paper: On the Correlation Between Residual Stresses and Displacements of the Polycrystalline Lattice: an Experimental Strategy

 

Authors: F. V. Díaz, F. N. Rosso, A. C. Walker, A. P. M. Guidobono

Pages: 208-214

http://doi.org/10.46300/9104.2020.14.27

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Abstract: This work aims to propose a micro-indent method to evaluate the correlation between the relaxation of residual stresses and the shape changes of the polycrystalline lattice in specimens of a rolled plate of AA 6082-T6 aluminium alloy. Rolling strengthens the surface of the plate by introducing compressive residual stresses. Then, these stresses are relaxed by thermal distension. The method of micro-indents allowed measuring residual displacements with an error below ± 300 nm. The results obtained reveal that the rolling direction plays a vital role in terms of asymmetric expansion of the lattice. Furthermore, the lattice accumulates and restores elastic strain energy in the clockwise and anti-clockwise direction of rotation, alternatively. Finally, when the stress release process is finishing, the lattice adjusts the angle of rotation to approximate to the initial geometric shape


Title of the Paper: Comparison of Single Vehicle Noise Emission Models in Simulations and in a Real Case Study by Means of Quantitative Indicators

 

Authors: Gabriella Graziuso, Simona Mancini, Claudio Guarnaccia

Pages: 198-207

http://doi.org/10.46300/9104.2020.14.26

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Abstract: Road traffic has a significant influence on the environmental noise pollution, producing harmful effects on human health and collective well-being. Since noise measurements cannot be performed everywhere, or even in a large number of sites, because of high costs and time consumption, traffic noise predictions are necessary for noise abatement and control. Consequently, many scientific models have been developed in recent years focusing on this aspect with the definition of source emission and sound propagation empirical formulations exclusively. This paper focuses on some Emission Models, describing the comparison of the results, in terms of sound power level emitted by a single vehicle, obtained with their application to different simulations of driving conditions and to two real study cases. After a preliminary comparison between the models, the evaluation of two indicators, namely the average and total source power level, will be discussed in relation to different conditions of the vehicle kinematics. The application of these two indicators to real study cases will demonstrate their validity. It will be shown that this procedure can become a tool for supporting people route choices according to a less impact of environmental noise. This will open the way to new scenarios of eco-routing, by means of implementation of models prediction in dedicated software platforms and/or in car navigation systems.


Title of the Paper: On a Computational Approach to Micro- and Macro-modelling of Damage in Brittle and Quasi-brittle Materials

 

Authors: Jiri Vala, Vladislav Kozak, Petra Jarosova

Pages: 185-197

http://doi.org/10.46300/9104.2020.14.25

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Abstract: Computational modelling of damage in brittle and quasi-brittle materials needs some coupling between micro- and macroscopic crack initiation and evolution, up to their non-negligible softening behaviour. Most such approaches contain ad hoc evaluations, with some physical and engineering motivations, namely those connected with massive application of steel bre-reinforced concrete and similar composites in building projects, but without any proper mathematical existence and convergence analysis for the time development of damage. This paper presents a possibility of such deterministic analysis on a selected model problem of structural dynamics, supplied by comments to useful directions of generalization. Several application examples document the feasibility of such approach, up to its software implementation and real data validation.


Title of the Paper: The Study of Methods for Combined Processing of Deep Holes of Hydraulic Cylinders

 

Authors: Meruert A. Berikbaeva, Beibyt T. Khairullin, Railya M. Mukhamadeyeva

Pages: 177-184

http://doi.org/10.46300/9104.2020.14.24

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Abstract: Obtaining of the quality of the inner surface of the hydraulic cylinders and its optimization is an urgent problem in the enterprise. The article presents the results of a study to improve the finishing process of deep holes in thin-walled sleeves. The authors used the combination of the cutting process and surface plastic deformation for improving metal processing. The selected main parameters for ensuring the quality of the surface are roughness index and the value of internal stresses in the surface layer of hydraulic cylinders. To determine the hardening depth of the inner surface of the deep hole of the liner, the oblique thin section method was used. A mathematical model of the combined processing was obtained. The research results make it possible to recommend combined hole processing that combines cutting and plastic deformation. The results obtained in this work will improve the processing of deep holes of hydraulic cylinders, and the developed mathematical model has practical and theoretical scientific value.


Title of the Paper: Spatial Analysis and Temporal Trend of Registered Noise Complaints in the City of Milan, Italy

 

Authors: R. Benocci, S.S. Muchetti, D. Salvi, F. Angelini, G. Brambilla, G. Zambon

Pages: 168-176

http://doi.org/10.46300/9104.2020.14.23

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Abstract: Noise complaints, expressed by individuals or a group of people, are the outcome of a complex behaviour depending not only on the noise exposure and its evoked annoyance, but also on other factors such as socio-economic ones. Noise annoyance has significant impacts on the quality of life and health of inhabitants, as well as social cohesion. Thus, noise complaints are a very important issue to tackle for national and local policy makers and for all stakeholders involved in planning and management of noise mitigation actions. Within the above framework, the present study describes the analysis of noise complaints submitted by citizens to the municipality of Milan, Italy, from years 2000 to 2015. These complaints have been organized in a database and analyzed considering: i) types of noise source (technical facilities, music, transport infrastructures, etc.); ii) business/leisure activities (retail and catering businesses, production, service sector, etc.) and iii) outcomes of the complaints inspection by local authorities. In addition, by means of a GIS software, the territorial distribution of noise complaints has been determined according to the noise source category and disturbing activity. This analysis includes also a geo-statistical representation by density maps. The results show that, even though road traffic is the dominant noise source in residential and urban areas, the perception of other noises, such as those from industrial facilities, civil construction and social activities (parties, fairs and open air markets, residential noise, etc.), is perceived as more annoying. The results show that since 2007 the number of noise complaints (about 100-150 complaints/year) remains almost constant across the years. However, the spreading of leisure activities, malls, exhibition centers and venues, as observed for the years 2014-2015, would most likely grow them even more. This outcome can assist the local authority in the management of the activities in order to reduce their harmful impact on the population.


Title of the Paper: Finite Element Models and Numerical Analysis of a Structural Glass Beam Reinforced with Embedded Carbon Fibre Rod

 

Authors: Dora Foti, Michela Lerna, Leonarda Carnimeo, Vitantonio Vacca

Pages: 163-167

http://doi.org/10.46300/9104.2020.14.22

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Abstract: Due to the its brittleness and unpredictable failure behaviour, the glass is considered a structurally unsafe material. The poor tensile strength and the occurrence of brittle failures prevent the possible use of structural glass elements (i.e. floors, beams and columns). The present study focuses on the numerical analysis of glass beams reinforced with composite material (Fiber Reinforced Polymer) and the numerical analysis of the behaviour of glass plates after being punched. In particular, the method of reinforcement analysed consists in embedding the Carbon FRP-rod in the interlayer of laminated structural glass beams with the aim to increase their failure strength, but also the post-failure strength and ductility. A numerical analysis on different specimens has been carried out to evaluate the effect of the reinforcement. The response of the reinforced and un-reinforced beams has been compared and the results have been discussed. The results provide an estimation of the expected performance in order to propose a reinforcement method for glass beams using FRP composites. This study includes the numerical analysis on laminated glass plates with wide holes at both ends, the latter made for technological reasons to connect the glass beam to the structure. The obtained results are compared with integer specimens.


Title of the Paper: Proposed Method for Two Axis Tracking of PV Modules using Advanced Microcontroller

 

Authors: Emad A. Sweelem, Mohamed I. Abu El-Sebah, Fathy A. Syam, Abouelmaaty M.Aly, Hanaa M.Farghally

Pages: 157-162

http://doi.org/10.46300/9104.2020.14.21

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Abstract: In this study, a stand-alone photovoltaic power system was designed and implemented to operate as an application of a digital control system. Sun-tracker is implemented for improved efficiency of the system by keeping the solar module perpendicular to the sun's incoming rays. An experimental system was implemented to demonstrate the effectiveness of the proposed system. Experimental results are given to verify the system's efficiency. A proposed method is employed to seek the maximum power point using two lighting sensors the data obtained from a two sensor is compared by microcontroller. Microcontroller is making PV module track the maximum sun light which leads to obtain a maximum power. The system is implemented using microcontroller and stepper motor and experimental work used to prove feasibility of the proposed method.


Title of the Paper: V-belts and Their Performance Resulting from Their Inner Hybrid Structure

 

Authors: Zuzana Murčinková, Svetlana Radchenko, Tibor Krenický, Jozef Maščeník

Pages: 151-156

http://doi.org/10.46300/9104.2020.14.20

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Abstract: Paper provides a study and comparison of narrow and classical cross-sections of five V-belts with different inner structure, material composition and shape. The performance is evaluated by non-contact monitoring of transversal vibration velocity together with belt temperature caused by friction and vibrations at various operational states when changing the loading, revolutions of driver pulley and tensioning force. Moreover, the vibration regimes are observed. The study presents whether concave sides, adhesion layer, higher compression core, transverse reinforcing fibers, notches, wrap of profile, naked belt sides cause the different performance.


Title of the Paper: On the Long-time Behavior of the Solution of a Non Linear Viscoelastic Plate Equation with infinite Memory and General Kernel

 

Authors: Adel M. Al-Mahd

Pages: 141-150

http://doi.org/10.46300/9104.2020.14.19

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Abstract: In this paper, we investigate the asymptotic behavior of the solution of a nonlinear viscoelastic plate equation with infinite memory. The nonlinearity in this problem is of a logarithmic type. We use a minimal condition on a relaxation function that is where ξ is a nonincreasing function and H is an in- creasing and convex function near the origin. We establish an explicit energy decay formula under this very general assumption on the behavior of the relaxation function at infinity. Our results substantially improve some earlier results in the literature.


Title of the Paper: Optimization of the Electric Vehicle HVAC Duct System based on Gradient Method

 

Authors: A. Maksimov, D. Igoshina, R. Petrov, O. Klyavin

Pages: 135-140

http://doi.org/10.46300/9104.2020.14.18

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Abstract: The transient duty has a very important role within the kinematical linkages of the numerical control machine tools and industrial robots. The acceleration and deceleration of the movable element of the kinematical linkage participates directly to achieving the positioning accuracy and to the path error. This work presents the main shapes of the acceleration- deceleration curve of the kinematical linkage, as well as their performances. Shapes of the acceleration-deceleration curve are presented for positioning linkages as well as for contouring linkages. The extent of influence upon the contour error in case of the linear and exponential acceleration-deceleration of kinematical linkage is also presented. The works is also giving recommendations on the way of choosing the type of curve being used in case of various transient processes, by the machine tool builders, with a view to obtaining high dynamical performances. In general, the recommendations are considering the inertia of the mobile element and the imposed path error. By knowing the acceleration shape, the machine tool designer and builder can know, even from the design stage, the area of the transient duty where the acceleration is maximal. The maximum acceleration imposes the rate of the impulsion torque of the drive servomotor based on which the kinematical linkage is sized, in terms of its components.


Title of the Paper: CFD Investigations of the Effect of Rotating Wheels, Ride Height and Wheelhouse Geometry on the Drag Coefficient of Electric Vehicle

 

Authors: A. Alekseev, A. Maksimov, A. Tarasov

Pages: 130-134

http://doi.org/10.46300/9104.2020.14.17

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Abstract: The development of electric vehicles demands minimizing aerodynamic drag in order to provide maximum range. The wheels contribute significantly to overall drag coefficient value because of flow separation from rims and wheel arches. In this paper various design parameters are investigated and their influence on vehicle drag coefficient is presented. The investigation has been done with the help of computational fluid dynamics (CFD) tools and with implementation of full vehicle setup with rotating wheels. The obtained results demonstrate changes in drag coefficient with respect to the change of design parameters.


Title of the Paper: Performances and Shapes of Acceleration-deceleration Curve of Kinematical Linkages

 

Authors: Ioan Enescu

Pages: 125-129

http://doi.org/10.46300/9104.2020.14.16

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Abstract: The transient duty has a very important role within the kinematical linkages of the numerical control machine tools and industrial robots. The acceleration and deceleration of the movable element of the kinematical linkage participates directly to achieving the positioning accuracy and to the path error. This work presents the main shapes of the acceleration- deceleration curve of the kinematical linkage, as well as their performances. Shapes of the acceleration-deceleration curve are presented for positioning linkages as well as for contouring linkages. The extent of influence upon the contour error in case of the linear and exponential acceleration-deceleration of kinematical linkage is also presented. The works is also giving recommendations on the way of choosing the type of curve being used in case of various transient processes, by the machine tool builders, with a view to obtaining high dynamical performances. In general, the recommendations are considering the inertia of the mobile element and the imposed path error. By knowing the acceleration shape, the machine tool designer and builder can know, even from the design stage, the area of the transient duty where the acceleration is maximal. The maximum acceleration imposes the rate of the impulsion torque of the drive servomotor based on which the kinematical linkage is sized, in terms of its components.


Title of the Paper: On the Problem of Optimizing the Door Hinge of Electro Car by Generative Design Methods

 

Authors: R. Petrov, P. Cvetkov, A. Maksimov, O. Klyavin

Pages: 119-124

http://doi.org/10.46300/9104.2020.14.15

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Abstract: Our research describes the optimization of car door hinges. The model we are considering is a pair of upper and lower hinges of car doors and cases of their loading. Optimization of this part of the vehicle consists in reducing the mass of the product, which is taken as the target function, while maintaining the mechanical characteristics within acceptable values. The characteristics of various types of manufacturing, such as milling, casting, and additive manufacturing, were also used as optimization criteria. During the research the authors have undertaken the task of using the most advanced approaches for calculation, optimization and analysis of their results, which are the use of special calculation systems, calculations that are performed on the GPU, what is the way much reduces the required optimization time, methods of generative design to achieve the required criteria and consideration of possible methods of manufacture of the workpiece in terms of additive manufacturing. The result of our research is the concept of optimizing vehicle door hinges and selecting the appropriate production method. As a test of the positive effect of the applied method, a repeated static calculation of the structure was made, based on the optimized geometry.


Title of the Paper: Limit States of Structures and Global Sensitivity Analysis Based on Cramér-von Mises Distance

 

Authors: Zdeněk Kala

Pages: 107-118

http://doi.org/10.46300/9104.2020.14.14

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Abstract: This article presents a stochastic computational model for the analysis of the reliability of a drawn steel bar. The whole distribution of the limit state function is studied using global sensitivity analysis based on Cramér-von Mises distance. The algorithm for estimating the sensitivity indices is based on one loop of the Latin Hypercube Sampling method in combination with numerical integration. The algorithm is effective due to the approximation of resistance using a three-parameter lognormal distribution. Goodness-of-fit tests and other comparative studies demonstrate the significant accuracy and suitability of the three-parameter lognormal distribution, which provides better results and faster response than sampling-based methods. Global sensitivity analysis is evaluated for two load cases with proven dominant effect of the long-term variation load action, which is introduced using Gumbel probability density function. The Cramér-von Mises indices are discussed in the context of other types of probability-oriented sensitivity indices whose performance has been studied earlier.


Title of the Paper: Droplet Formation of an Anisotropic Liquid

 

Authors: A. Pezzutti, G. Araujo

Pages: 100-106

http://doi.org/10.46300/9104.2020.14.13

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Abstract: The process of formation of new morphologies by confinement in nano-droplets, created from a dewetting process, was simulated. The obtained structures showed a great similarity with the experimental results present in the literature. The developed model captures the fundamental interactions that determine the dynamics of the phase separation process of a copolymer system confined between a rigid substrate and a free surface. Furthermore, its numerical resolution is highly efficient as a result of the implementation of Eyre algorithm.


Title of the Paper: Dynamic Time Analysis of Glass Fiber Reinforced Polymer – Numerical Simulation and Experiment

 

Authors: Zuzana Murčinková

Pages: 94-99

http://doi.org/10.46300/9104.2020.14.12

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Abstract: Composites are known for their significant damping, however, both reinforcement type or layered arrangement influence the response of material: mechanical, thermal, electrical etc. The paper provides the dynamic time analysis of glass fiber reinforced polymer samples of various layups. The mechanical response to dynamic excitation was tested by numerical simulation and experiment. The excitation function was the unit impulse force generating free damped vibrations. Experimental results were evaluated in time domain to obtain damping parameters. For numerical simulation, the commercial software was used to visualize deformed model in individual damping phases, Mises stress distribution in individual laminate layers, and comparison of that for different layups.


Title of the Paper: CAE Modeling Rubber-metal Body Mounting of the Body-on-frame Car in Crash Simulations

 

Authors: V.A. Tsittser, S.V. Alekseev, A.V. Tarasov, A.I. Borovkov

Pages: 87-93

http://doi.org/10.46300/9104.2020.14.11

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Abstract: The aim of the study was to research the behavior of the rubber-metal body mounting under various modeling options and to select the optimal, from the point of view of ensuring the accuracy of the results in the crash tests simulations. Body supports provide a link between the body and the car frame, and this has a critical effect on the impact test results of the car. The article discusses various options for modeling the body mounting by the degree of simplification from the simplest model with a rigid connection between the body and the frame to the model that takes into account the non-linearity of the stiffness characteristics of the supports, contact interaction between parts of the mounting and its surrounding parts, tension of the supports and failure. The results of virtual tests of a car with various options for modeling mountings were compared with the results of real tests. As a result of the study, a methodology for modeling the body supports was developed, which allows providing the necessary measurement error in virtual crash test modeling.


Title of the Paper: Design of Estimator for Computing Yaw and Pitch for a Twin Rotor MIMO system

 

Authors: Santhosh K. V., Preeti Mohanty

Pages: 79-86

http://doi.org/10.46300/9104.2020.14.10

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Abstract: Performance of any system is identified through the observation of significant system parameters. Required parameters have to be measured using suitable sensors. But in some scenarios, it is difficult to measure some of the parameters due to issues in the placement of sensors. In such cases, estimators are developed to measure the parameters indirectly. In this paper, an attempt is made to develop an estimator to monitor the value of pitch and yaw of a twin-rotor multi input multi output system. The observer is developed using two methods one using Luenberger’s equations and the other using an Artificial Neural Network (ANN). For training the neural network model, the backpropagation algorithm is used. Tests have been conducted to analyze and compare the behavior of both observers. From the results, it is evident that a Luenberger observer performs better when sufficient system information is available and ANN observer performs better when inadequate system information is available.


Title of the Paper: Analysis of the Spatial Behaviour of Masonry Bridges Via Hierarchical FEM Modelling: the Devil’s Bridge

 

Authors: I. Corbi, O. Corbi, F. Tropeano

Pages: 72-78

http://doi.org/10.46300/9104.2020.14.9

Abstract: The contribution of the fill to the global behavior of masonry vaulted bridges may be primarily significant. Nevertheless, ordinary analyses conducted on masonry bridges usually consider only the main structural vaulted elements. The paper reports some results obtained through a numerical simulation developed on a FEM model of an ancient bridge, the Devil’s bridge on Sele river at Barrizzo, in the Campania region. The study is aimed at showing how the fill may be contributing with a significant static action , changing the real carrying capacity of the bridge as regards applied loads. The study allows to highlight the spatial behavior of the single components and of the overall structure as well, in terms of stresses and deformed configurations under the self- weight and the accidental loads.


Title of the Paper: Approximations of the Sixth Order with the Polynomial and Non-polynomial Splines and Variational-difference Method

 

Authors: I. G. Burova

Pages: 62-71

http://doi.org/10.46300/9104.2020.14.8

Abstract: This paper discusses the approximations with the local basis of the second level and the sixth order. We call it the approximation of the second level because in addition to the function values in the grid nodes it uses the values of the function, and the first and the second derivatives of the function. Here the polynomial approximations and the non-polynomial approximations of a special form are discussed. The non-polynomial approximation has the properties of polynomial and trigonometric functions. The approximations are twice continuously differentiable. Approximation theorems are given. These approximations use the values of the function at the nodes, the values of the first and the second derivatives of the function at the nodes, and the local basis splines. These basis splines are used for constructing variational-difference schemes for solving boundary value problems for differential equations. Numerical examples are given


Title of the Paper: Compressive Strength of Interlocking Concrete Pavement Block influenced by Admixtures

 

Authors: Parinita Baruah, Sudip Basack, Ghritartha Goswami

Pages: 58-61

http://doi.org/10.46300/9104.2020.14.7

Abstract: The interlocking concrete pavement blocks are quite commonly used to construct the pedestrian walkways and parking lots of transport infrastructure. Such blocks need adequate compressive strength to withstand the design live loads. In this paper, the influence of admixtures on the compressive strength of the blocks are studied through a series of laboratory investigations. The M35 grade of concrete conforming to the Indian Standard code of practice has been used with a standard superplasticizer as admixtures added at specified weights. The study implied that the use of admixtures alters the compressive strength of concrete blocks significantly.


Title of the Paper: CFD Study for the Flow Behaviour of Nanofluid Flow over Flat Plate

 

Authors: M. M. Klazly, G. Bognár

Pages: 49-57

http://doi.org/10.46300/9104.2020.14.6

Abstract: Computation fluid dynamics (CFD) modelling of laminar heat transfer behaviour of three types of nanofluids over flat plate are studied. In the modelling the two dimensional under laminar model is used. The base fluid is pure water and the volume fraction of nanoparticles in the base fluid is 0, 1, 2, 3, and 4%. The applied Reynolds number range considered is 997.1 ≤ Re ≤ 9971. For modelling of the physical properties of the nanofluid, single phase approach is used. The effect of the volume fraction and the type of nanoparticles on the physical properties has been evaluated and presented. Then, the analysis the flow behaviour of these three nanofluids is conducted by presenting the effect of increasing the nanoparticles concentration on the velocity profile, wall shear stress, skin friction coefficient, and average heat transfer coefficient. The results show that the type of nanoparticles is an important parameter for the heat transfer enhancement as each type has shown dissimilar behaviour in this study. Moreover, a polynomial correlation has been obtained to present the relation of the wall shear stress, skin friction coefficient and average heat transfer coefficient as a function of the volume fraction for the three nanofluids.


Title of the Paper: Coastal Ground Water Flow and Management: A State-of-the-Art Review

 

Authors: Ghritartha Goswami, Sudip Basack, Nikos Mastorakis, Abhishek Saikia, Baby Nilo, Nasir Ahmed

Pages: 37-48

http://doi.org/10.46300/9104.2020.14.5

Abstract: Seawater intrusion has led to salinization of fresh groundwater reserves in coastal areas worldwide and has forced the closure of water supply wells. There is a paucity of well-documented studies that report on the reversal of SWI after the closure of a well field. Saline water from a storm surge can flow down storm-damaged submerged water supply wells and contaminate boreholes and surrounding aquifers. Water is an invaluable commodity in nature and can be a limiting resource to man and other living beings. Water quality is influenced by both natural and anthropogenic intervention where the former includes local climate, geology etc., and the latter covers the construction of dams and embankments, irrigation practices, indiscriminate disposal of industrial effluents etc. Therefore, it is highly desirable to properly manage groundwater resources for drinking-water supply by controlling saltwater intrusion. A cost effective method Abstraction, Desalinization and Recharge was found to be efficient.


Title of the Paper: Entropy Generation of MHD Poiseuille Flow with Hall and Joule Heating Effects

 

Authors: A. A. Opanuga, O. O. Agboola, H. I. Okagbue, A. M. Olanrewaju

Pages: 28-36

http://doi.org/10.46300/9104.2020.14.4

Abstract: In this article investigation has been conducted on the effects of Hall parameter, rotation parameter and Joule heating on the entropy generation of fully developed electrically conducting Poiseuille flow. The coupled system of ordinary differential equations for the flow are obtained, non-dimensionalised and solutions are constructed by Adomian decomposition technique. The effects of Hall current, Ion-slip, Joule heating and magnetic parameters on the velocity, temperature, entropy generation and Bejan number are explained and shown graphically. The results indicate that fluid entropy generation is induced by increase in Hall current, rotation and Joule heating parameters. Furthermore Bejan number is accelerated by Hall current, rotation, Magnetic and Joule heating parameters which signifies that heat transfer irreversibility dominates entropy generation.


Title of the Paper: Analysis and Control of Flow Parameters through Sluice Gate in Dam

 

Authors: Sudip Basack, Ghritartha Goswami, Prandeep Deka, Partha Pratim Borah, Nikos Mastorakis

Pages: 22-27

http://doi.org/10.46300/9104.2020.14.3

Abstract: Controlling the discharge through a gravity dam by means of sluice gate is quite common technique. Although extensive theoretical and experimental studies on discharge parameters are available, most of these studies reported sedimentation and river-bed conditions resulting in reduced discharge through a dam, although limited research has focused on controlling and adjusting the discharge considering practical scenario. This paper presents a simplified analytical model applied to a typical case study on a typical dam in western India which was used the lift irrigation technique for improving the discharge. The approach focuses on the parametric studies for predicting the variations in discharge ratio employing a range of geometrical parameters such as area and aspect ratio of the individual sluice gates and their total number. It was found that the discharge is largely affected by minor alteration in these parameters. A set of important conclusions was drawn from the entire study.


Title of the Paper: Solving the Problem of Constraints Due to Dirichlet Boundary Conditions in the Context of the Mini Element Method

 

Authors: Ouadie Koubaiti, Ahmed Elkhalfi, Jaouad El-Mekkaoui, Nikos Mastorakis

Pages: 12-21

http://doi.org/10.46300/9104.2020.14.2

Abstract: In this work, we propose a new boundary condition called CA;B to remedy the problems of constraints due to the Dirichlet boundary conditions. We consider the 2D-linear elasticity equation of Navier-Lam´e with the condition CA;B. The latter allows to have a total insertion of the essential boundary condition in the linear system obtained without going through a numerical method like the lagrange multiplier method, this resulted in a non-extended linear system easy to reverse. We have developed the mixed finite element method using the mini element space (P1 + bubble, P1). Finally we have shown the efficiency and the feasibility of the limited condition CA;B.


Title of the Paper: Slurry Pipeline for Fluid Transients in Pressurized Conduits

 

Authors: Tarik Chakkour, Fayssal Benkhaldoun

Pages: 1-11

http://doi.org/10.46300/9104.2020.14.1

Abstract: Morocco is known by the pipeline from Khouribga to Jorf Lasfar that is considered as one of the most world’s largest for the slurry transportation. This phosphate slurry undergoes different manufacturing process. During this process, the rheological properties of the slurry have been taken into account, and next adapted for our study. There are numerous approaches in the literature which investigate different Eulerian-Lagrangian, Eulerian-Eulerian and Stochastic models to simulte the slurry flow [1], [2]-[3]. Actually, it is very difficult to consider all variables for establishing a general model, we build an Eulerian and a homogeneous one in easier framework. Among these variables, there is the stress tensor which is involved in the model. Since it is considered null, then the non-Newtonian fluid is approched by multiple friction factors. In the present work, a onedimensional three-fluid model is developed in Python. The physical model features a mass and momentum balance for each fluid. It allows to predict the pressure drop and flow patterns. The hydraulic transport of slurry system in horizontal tubes has been investigated. To simulate it dynamically, continuity and momentum equations used in applied engineering problem, are solved together. These equations are conveniently solved using the method of characteristics (MOC). The reason for utilizing this method is the robustness and efficiency compared to the finite volume method (FVM). The originality for this work takes into account the physical discontinuity at interface separating slurry and water which mix with each other. The numerical results from the numerical code model head and pressure losses. We test numerically the fitting of the model with the real physical problem. Then the model is used on simplified examples in order to show its capability to be used to predict the flow behaviour in different regimes, showing consequently its consistency.