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Home>Products>Journal and Reviews>I.RE.M.E.>Latest issue
International Review of Mechanical Engineering - March 2010 - Papers
International Review of Mechanical Engineering - Papers
Vol. 4. n. 3, pp. 216-221
Abstract - Taguchi method offers a simple and systematic approach to optimize performance, quality and cost in manufacturing process. Taguchi optimization methodology was applied to optimize cutting parameters in turning of Ti-6Al-4V ELI with coated and uncoated cemented carbide tools. The turning parameters evaluated were cutting speed, feed rate, depth of cut and tool grade, each at three levels. The results of analysis show that the feedrate and type of tool have the most significant effect on the surface roughness with contributions of 47.15% and 38.88% respectively. The optimal condition for the surface roughness was at cutting speed of 95 mm/min, feed rate of 0.15 mm/rev, depth of cut of 0.10 mm and using tool grade of KC9225. Whereas optimum material removal rate was obtained at cutting speed of 75 mm/min, feed rate of 0.25 mm/rev, depth of cut of 0.15 mm and using tool grade of K313. Copyright © 2010 Praise Worthy Prize S.r.l. - All rights reserved
Keywords: Taguchi Method, Ti-6Al-4V ELI, Carbide Insert, Surface Roughness, Material Removal Rate.
Vol. 4. n. 3, pp. 222-227
Abstract - The
practical importance of the drift-flux model for two-phase flow analysis
was the main reason for the study of distribution parameter and drift
velocity in slug-churn flow regimes. Formulating two-phase problems in
terms of the drift-flux model, in which the motion of the whole mixture
is expressed by the mixture-momentum equation and the relative motion
between phases is taken into account by a kinematic constitutive
equation, reduces the difficulties associated with a two-fluid model.
Copyright © 2010 Praise Worthy Prize S.r.l. - All rights reserved
Keywords: Fluid Mechanics, Mass Transfer, Two-phase Flow, Voidage, Drift-flux Model, Air-lift Pump, Distribution Paramete.
Vol. 4. n. 3, pp. 228-232
Abstract -
The thermomechanical behaviour and the characterization of two material
couples ferromagnetic/ferromagnetic and non ferromagnetic/ferromagnetic
in a sliding contact subjected to an alternative magnetic field were
studied. Copyright © 2010 Praise Worthy Prize S.r.l. - All rights reserved Keywords: Friction, Wear, Magnetic Field, Oxidation, Third Body, Oxide Film, Texture.
Vol. 4. n. 3, pp. 238-243
Abstract - An investigation on the effect of solution treatment on fatigue crack propagation (FCP) behaviour of AZ61 magnesium alloy was carried out. A centre cracked plate tension (CCT) specimen was prepared from an extruded cylindrical AZ61 magnesium alloy rod. The solution treatment was performed at 400oC for one hour to get homogeneous solid solution before quench in water. The FCP test was conducted in a laboratory air environment under a constant amplitude sinusoidal loading with a stress ratio of 0.1 and a frequency of 10 Hz. The FCP curve for solution treated samples was then compared to that of the extruded AZ61 magnesium alloy. Results showed that solution treatment shifted the FCP curve to the left and demonstrated a lower fatigue crack propagation resistance at the high stress intensity region. The threshold value was recorded at 0.91 MPa√m.. Copyright © 2010 Praise Worthy Prize S.r.l. - All rights reserved
Keywords: Fatigue Crack Propagation, Solution Treatment, Threshold Value, Magnesium Alloy.
Abstract - In internal combustion engines valve events and timings are among the most important parameters which have a major influence on the volumetric efficiency and engine's performance. Variable valve timing (VVT) provides improvements in engine efficiency and performance by changing the valve lift and timing as a function of engine operating conditions. In this paper the obtained results by using the mathematical simulation pattern are presented by Simulating a VVT engine operation and load control through the inlet valve. Different degrees of Freedom for a variable intake profile such as variable intake duration and variable valve lift are considered and evaluated concerning their potential to optimize intake-lift profile for maximum volumetric efficiency over the whole engine speed range. Using camless valvetrain strategy, improvement in fuel economy as well as an increase in intake air charge is found throughout the engine map with the largest benefits arising from low speed operating conditions. The system offers a continuously variable and independent control of virtually all parameters of valve motion. This permits optimization of valve events for each operating condition without any compromise. In this paper we describe a phenomenological model for an unthrottled operation of a camless intake process in a spark-ignited (SI) engine. Initially the cylinder breathing dynamics is modeled and results are validated with experimental data of a conventional engine with a cam-driven valve profile during unthrottled operation. Then we determine the most optimized intake valve profile and timing in order to have the best volumetric efficiency and improved operation for each operating condition based on the existing model through numerical techniques. Copyright © 2010 Praise Worthy Prize S.r.l. - All rights reserved
Keywords: Optimization, SI engine, Variable valve timing, Volumetric Efficiency.
Vol. 4. n. 3, pp. 233-237
Abstract - In this research, the practicability of substituting the composite materials with steel in crane structure was studied by computer -aided finite element analysis. Three composite materials were compared to steel through stress analyses of crane components. The analyses were performed in identical circumstances with the same loads applied to the components .The criterion to compare the strength of components was based on the factor of safety (FOS). Results show that the entire corresponding composite materials have the higher FOS-to weight ratio than steel but among them, glass epoxy has the highest FOS- to weight ratio and can be appropriate substitute for steel in crane structure. Copyright © 2010 Praise Worthy Prize S.r.l. - All rights reserved
Keywords: Composite Materials, Crane, Factor Of Safety, Finite Element Analyses, Steel.
Vol. 4. n. 3, pp. 253-269
Abstract - The flow around circular cylinder especially near the wake of a cylinder will have a remarkable interest in the industrial applications like flow around bluff bodies. The use of injection parameter concept to explain the link between the vortices generation, dissipation with the mean motion. The injection parameter will help to highlight the coupling between organized motion and the small scale eddies. The injection parameter extracted from a new generic pressure gradient equations, which it will be formulated as a function of Magnus forces of fluid flow and its gradients. The pressure gradient equation will be the key for solving the momentum equations. A new turbulence model will solve the momentum equations using a turbulence closure of Reynolds stresses components equations. The Reynolds stresses components will be expressed as a function of Magnus forces of fluid flow and its gradients. The numerical solutions using the new turbulence model will be compared to experimental results in order to explain the flow behavior near the wake and downstream of circular cylinder flow. Copyright © 2010 Praise Worthy Prize S.r.l. - All rights reserved
Keywords: Turbulent Flow, High Reynolds Number, Flow Around Cylinder, Turbulence Modeling.
Vol. 4. n. 3, pp. 270-280
Abstract -
This paper presents the simulation of laminar natural Convection in square
cavity with a wavy wall. The cavity consists of one wavy wall and three
straight walls. Two vertical walls kept isothermal and one of them is
wavy (right). Two horizontal walls are considered adiabatic. The
governing equation in primitive variables (u,v,p,T) are solved
numerically using an implicit fractional step method. The current method
was developed for use on an unstructured grid made up of triangles. The
basic principles of this method are that the evaluation of the time into
intermediate steps. Result are presented in the form of local and main
Nusselt number distributions for various Rayleigh number and for Prandtl
number 0.71.streamlines and isothermal lines are also presented for
different values of amplitude.
Keywords: Natural Convection, Laminar Flow, 2D Modeling, Implicit Fractional Step Method, Unstructured Grid Made Up of Triangles, Wavy Wall, Amplitude.
Vol. 4. n. 3, pp. 281-287
Abstract -
The paper introduces an efficient computational tool for predicting the
convective drying behavior of capillary porous, hygroscopic materials.
This ability is forecasting the drying behavior is an important
prerequisite for the prompt and cost efficient optimization are the
enhancement of product quality, better process control, more efficient
use of the drying equipment and the reduction energy utilization. In
this study, measurements are carried out for concrete reinforced with
wood chips CRWC and concrete and we are established experimentally
correlations for heat transfer calculation.
Keywords: Thermal Conductivity, Drying, Heat Transfer, Porous Material, Building Material.
Vol. 4. n. 3, pp. 288-296
Abstract -
The influence of the plume source temperature in the structure of a
thermal plume evolving in a heated vertical canal has been studied. For
that an experimental apparatus comprising a rectangular source was
placed at the entrance of a vertical canal of a rectangular section open
at both ends on quiet environment of uniform temperature. The thermal
plume generated by a heated source is added to a thermosiphon flow that
develops at the walls of the canal. A visualization by laser plane has
shown that the system was fed from the bottom through by three fresh air
nets, the existence of a hot envelope just above the source and also
three different zones of flow as has been noted in previous work on
cylindrical geometry. The study of the thermal and dynamics fields,
performed by hot wire and constant current anemometry, has shown that,
contrary to previous work, the blocking of the lateral extension of the
plume to the sides of the canal is not observed, the existence of three
areas already observed by flow visualization for all the temperatures of
the source studied. Moreover, the increase of the temperature of the
source allows a larger lateral transport, improves flow rate of the flow
and intensifies heat transfer.
Keywords: Thermal Plume, Plume Interaction Thermosiphon, Flatness and Skewness Factors.
Vol. 4. n. 3, pp. 297-304
Abstract -
This paper deals with the numerical solution of laminar natural convection
in a three-dimensional enclosure with one side walls maintained at
constant temperature and cooled from ceiling, while the other four end
walls are adiabatic. The simulation tools that we used in this paper are
the finite volume software FLUENT, and its accompanying mesh generation
software GAMBIT. Steady state solutions have been obtained for different
aspect ratios: 0.25, 0.5, 1 and 2 for Rayleigh numbers ranging from 103
to 106. The predicted temperature and velocity profiles as well as the
mean Nusselt number were presented and discussed. Good agreement has
been obtained.
Keywords: Natural Convection; Heat Transfer; Two-Dimensional Enclosure; Three-Dimensional Enclosure.
Vol. 4. n. 3, pp. 305-309
Abstract -
This paper presents an experimental study on vibratory behaviour of a
machine tool type lathe standard CN ALMO 50. When cutting, the
appearance of vibrations is inevitable. Once the amplitude exceeds the
allowable tolerance, these vibrations are a major obstacle to the
research for high productivity and better quality of machined parts. In
this work is highlighted the problem of vibrations reported to machine
tools: its origins, its consequences, solutions and direction of current
research, methods and ways to measure its importance. The obtained
results are exposed in the study and they show that the gear box is the
origin of the majority of these vibrations. Moreover the spindle speed
controls the level of the vibrations which is rather marked in the case
absolute vibrations. For the studied case, we show that the zone of
resonance is reached for a speed of 1000 rev min-1. It is found that the
gear box and the tool holder vibrate in phase with appreciably equal
amplitude ratio of the relative to the absolute vibrations is stabilized
between 125 to 500 rev min-1 and decreases drastically for 1000 rev
min-1.
Keywords: Vibration, Experimentation, Machine Tools, Frequencies.
Vol. 4. n. 3, pp. 310-321
Abstract - In this investigation the problem of evaluating approximate frequency for isotropic and orthotropic plates is done, based on the general formula of Hearmon. It is proposed here to calculate the fundamental mode of isotropic and orthotropic plates with two non-homogenous supports (cases: SCSC & SSCC). For the higher mode of modal frequency, a particular form of the method of Rayleigh is used leading to a simple procedure for calculating the fundamental frequency. A new simple and qualitative method is proposed and has permitted a good strategy to evaluate the quality of results obtained. In order to verify the precision of the proposed qualitative method, a confrontation with finite element method using ANSYS software was done. The complementary utilization of Hearmon’s principle and the qualitative method has also permitted a successful advance in evaluating higher modes. This combined procedure gives a strategy of a vibratory analysis of isotropic and orthotropic plates; it permits the satisfaction of the preliminary conception needs of the structure to be studied, and also provides a qualitative method for expertise and investigation of dynamical responses. In all cases, the dynamic investigation is based on some evaluation criteria such as: limit conditions effect, plate dimensions ratio effect, material effect and mode number effect. Copyright © 2010 Praise Worthy Prize S.r.l. - All rights reserved
Keywords: Free Vibration, Rectangular Thin Plate, Isotropic-Orthotropic, Circular Frequency, Nodal Lines Position, Qualitative Analysis Method, Rayleigh Method, Finite Element Method.
Vol. 4. n. 3, pp. 322-329
Abstract -
From known theoretical developments, in the field of dynamics of
homogeneous beams, Euler Bernoulli (case of slender beams), two
homogenisation approaches of composite beams are developed, the fist,
based on equivalent physical characteristics (approach I) while the
second is based on the equivalent mechanic-geometrical characteristics
(approach II). The equations of free motion and/or forced, are
established and the responses in terms of natural frequencies of
vibration and/or dumping factors of Rayleigh, taking into account
different boundary conditions, are obtained. For confirmation, the two
approaches results are compared with those obtained from a finite
element modelisation approach.
Keywords: Composite, Vibration, Multilayered Beam, Homogenisation, Global Equivalent Physical Properties, Global Equivalent Mechanical-Geometrical Properties, Rayleigh Dumping Factor, Linear Response Spectrum.
Vol. 4. n. 3, pp. 330-335
Abstract - This paper describes optimization of process planning in flexible manufacturing systems (FMSs). The FMS can be described as an integrated manufacturing system consisting of machines, robots, and conveyor. While FMSs give great advantages through the flexibility, FMSs pose complex problems of job scheduling and machine assignment on a flexible machining equipped with multiple parallel machines in a tool-sharing environment. Under these circumstances, authors have attempted to model the problem with the objective of simultaneously minimizing makespan. Furthermore, a set of realistic constraints has been included in the investigation. A metaheuristic has been developed to solve the problem, and performance results show that metaheuristic is an appropriate solution. Copyright © 2010 Praise Worthy Prize S.r.l. - All rights reserved
Keywords: Piloting, Optimization, Petri Nets, Genetic Algorithm, Simulates Annealing.
Vol. 4. n. 3, pp. 336-345
Abstract - This paper presents an approach to apply Digital Manufacturing - PLM (Product Lifecycle Management) techniques using them as support in collaborative automation projects design and implementation. This work proposes a general methodology to be used in Collaborative Projects, Research and Case Studies development, showing some of the supported by Mechatronics and used in Digital Manufacturing - PLM tools within an Interactive systematic that allow a proper environment where engineers and technologists can develop professional skills. The evaluation of this methodology is done through three case studies: Collaborative Design Automation, Implementation Methodology, Project and Implementation of Modeling and Architecture for Supervision and Control. Copyright © 2010 Praise Worthy Prize S.r.l. - All rights reserved
Keywords: Digital Manufacturing, Product Lifecycle Management - PLM, Mechatronics, Professional Education.
Vol. 4. n. 3, pp. 346-352
Abstract - There is a number of cases reported for pipeline failures both in onshore and offshore situation. In order to minimize such failure, there is a need to clearly understand the failure mechanisms, governing factors and further analysis of data can determine the cause and extent of failure. In this study Analytical Hierarchy Process (AHP) was used to determine the risk factor for pipeline failure of the chosen system. AHP provides the multiple criteria scoring results based on expert judgement for prioritizing the pipeline maintenance strategy. For this case study two pipelines networks administered by two different operators, the first one in Malaysia and the other one in Indonesia were chosen. From the analysis of the data obtained by interviewing the pipeline engineers from Malaysia operator, it was obtained that highest risk factor i.e. 41.7% for pipeline failure involved internal corrosion; the other factors in descending order are internal erosion, external impacts, external corrosion, free span and on-bottom stability. From the analysis of Indonesian pipeline, failure due to system operation involved the highest risk factor i.e. 34.7%; other factors are design index, maintenance, and third party index. Copyright © 2010 Praise Worthy Prize S.r.l. - All rights reserved
Keywords: Petroleum Pipelines, Risk analysis, Analytical Hierarchy process, Sensitivity Analysis.
Vol. 4. n. 3, pp. 353-357
Abstract - In this paper a kinematic and dynamic model of the human upper extremity is developed. The human upper extremity is modelled as a spatial mechanism with seven degrees of freedom. The input motions are the flexion-extension, abduction-adduction and external-internal rotation of the arm with respect to shoulder, the flexion-extension and pronation-supination of the elbow and the wrist flexion-extension and abduction-adduction motion. The developed model allows to simulate the upper extremity movement and to determine the input torques and joint forces under different loads. These results can be used for the detection of dangerous movements of a patient having orthopaedic problems or for the design of prosthetic devices. Copyright © 2010 Praise Worthy Prize S.r.l. - All rights reserved
Keywords: Dynamical Model, Joint Forces, Kinematics, Simulation, Upper Extremity Model.
Vol. 4. n. 3, pp. 358-363
Abstract - We present a numerical simulation of a CH4/air reacting coaxial jet confined in a cylindrical combustion chamber. This study focuses on non-premixed turbulent flame. The simulation, performed by Fluent software, is based on the coupling between Beta-PDF approach and LES-WALE model subgrid-scale. The numerical validation is confirmed by comparisons of predictions results and reference experimental data, Spadaccini et al. (1976). It showed that a good agreement and reliable statistically predictions against experimental data. Copyright © 2010 Praise Worthy Prize S.r.l. - All rights reserved
Keywords: Non-premixed turbulent combustion; Large eddy simulation; Joint scalar PDF; CFD.
Vol. 4. n. 3, pp. 364-369
Abstract - The
objective of this paper is the application of a new non-iterative
spectral method to nonlinear systems for the design or verification of
seismic structures subjected to seismic action. This method uses a
direct design procedure based on the displacements method, in which the
maximal allowed displacement and the building vulnerability are
initially defined, instead of sizing on the basis of the method of
forces, usually adopted by seismic codes. Copyright © 2010 Praise Worthy Prize S.r.l. - All rights reserved
Keywords: Capacity Curve, Capacity Spectrum, Performance Point, Fragility Curves, Risk Assessment, Vulnerability.
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