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Showing papers in "Journal of The Brazilian Society of Mechanical Sciences and Engineering in 2019"


Journal ArticleDOI
TL;DR: In this paper, the impacts of diesel-biodiesel-alcohol blends on the combustion, performance and emissions characteristics of a single-cylinder diesel engine were investigated, and the experimental results showed that the highest reduction values were observed on CO emission by 42%, 30% and 8% for the D90E10, D70C20E10 and D80C20 fuels, respectively.
Abstract: The purpose of this study is to investigate the impacts of diesel–biodiesel–alcohol blends on the combustion, performance and emissions characteristics of a single-cylinder diesel engine. Tests were conducted at different engine speeds of 1750, 2250, 2750 and 3250 rpm and under full load. In this study, different fuels [called as reference diesel (D100), 20 vol% cottonseed methyl ester (D80C20), 10 vol% ethanol (D90E10) and finally the ternary type of their derivations (D70C20E10)], were used. The experimental results showed that the highest reduction values were observed on CO emission by 42%, 30% and 8% for the D90E10, D70C20E10 and D80C20 fuels, respectively. These reductions for HC emission were achieved as 40%, 31% and 23% for the D90E10, D70C20E10 and D80C20, respectively. On the other hand, the reductions of NOx and CO2 emissions were not sharp and varied between 2–7%. Besides the reductions on the exhaust emissions, biodiesel–ethanol blend presented better results in terms of HRRmax and CPmax than using biodiesel alone. Additionally, ignition delay of the biodiesel blends was longer than that of D100 fuel owing to their low cetane numbers. Combustion duration was shortened with the increment in engine speed because the turbulence increased in the combustion chamber at high engine speed. This case also improved the homogeneity of test fuels and increased the quality of the combustion process. As a consequence, this paper clearly reported that it is possible to achieve fewer emissions, the highest CPmax values with the presence of ethanol in biodiesel fuels rather than using biodiesel alone for diesel engines.

126 citations


Journal ArticleDOI
TL;DR: In this paper, the effects of small scale are analyzed based on nonlocal strain gradient theory (NSGT) which is an accurate theory employing exact length scale parameter and nonlocal constant, and the governing equations of the GNP composite cylindrical nanoshell coupled with PIAC have been evolved using Hamilton's principle and solved with assistance of the analytical method.
Abstract: In this article, wave propagation characteristics of a size-dependent graphene nanoplatelet (GNP) reinforced composite cylindrical nanoshell coupled with piezoelectric actuator (PIAC) and surrounded with viscoelastic foundation is presented. The effects of small scale are analyzed based on nonlocal strain gradient theory (NSGT) which is an accurate theory employing exact length scale parameter and nonlocal constant. The governing equations of the GNP composite cylindrical nanoshell coupled with PIAC have been evolved using Hamilton’s principle and solved with assistance of the analytical method. For the first time in the current study, wave propagation electrical behavior of a GNP composite cylindrical nanoshell coupled with PIAC based on NSGT is examined. The results show that, by decreasing the PIAC thickness, extremum values of phase velocity occur in the lower values of the wave number. Another important result is that, by increasing GPL%, the effects of PIAC thickness on the phase velocity decrease. Finally, influence of PIAC thickness, wave number, applied voltage, and different GPL distribution patterns on phase velocity is investigated using mentioned continuum mechanics theory. Useful suggestion of this research is that for designing of a nanostructure coupled with PIAC attention should be given to PIAC thickness and applied voltage, simultaneously. The outputs of the current study can be used in the structural health monitoring and ultrasonic inspection techniques.

94 citations


Journal ArticleDOI
TL;DR: In this article, the impact of nonlinear thermal radiation and variable thermal conductivity on 3D flow of cross-nanofluid is explored and the required system of ordinary ones is achieved by implementing appropriate transformations.
Abstract: In view of ecological concern and energy security, execution of refrigeration system should be enriched which can be done by improving the characteristics of working liquids. The nanoliquids have gained interest in industrial and engineering fields due to their outstanding thermophysical features. Researchers used nanoliquids as working liquid and detected substantial variations in thermal performance. In the present research work, our intention is to explore the impact of nonlinear thermal radiation and variable thermal conductivity on 3D flow of cross-nanofluid. Moreover, heat sink–source, chemical processes and activation energy are implemented. Zero mass flux relation with thermophoresis and Brownian motion mechanisms are scrutinized. The required system of ordinary ones is achieved by implementing appropriate transformations. The achieved system of ordinary ones is computed numerically by implementing bvp4c scheme. Graphs are plotted to explore the impact of various physical parameters on concentration, temperature and velocity fields. It is detected from obtained graphical data that thermophoresis and Brownian motion mechanisms significantly affect heat transport mechanism. Furthermore, graphical analysis reveals that concentration of cross-nanofluid enhances for augmented values of activation energy.

93 citations


Journal ArticleDOI
TL;DR: In this article, the motion of a Trimaran vessel is numerically investigated for different longitudinal and transversal hull positioning using finite volume method in Flow-3D software, and vessel's motion is examined in the presence of regular waves and at different wave encounter angles.
Abstract: Sea environmental conditions such as waves and winds influence several parameters associated with the performance characteristics of Trimaran vessels such as speed, sailing safety, and dynamic forces acting on the structure. On the other hand, the desirable performance of the Trimarans in different sea conditions has attracted the attention of many researchers. However, there remains one of the important issues associated with the design of Trimaran, which is the arrangement of the lateral side hulls, which can help improve its performance. Accordingly, in the current paper, the motion of this type of vessel is numerically investigated for different longitudinal and transversal hull positioning using finite volume method in Flow-3D software. To this end, vessel’s motion is examined in the presence of regular waves and at different wave encounter angles. In addition to the optimization of the side hulls location, the dynamics of a Trimaran and its sensitivity to different sea conditions and vessel speed are studied. The computed results show that Trimaran vessels have suitable dynamics with lower longitudinal side body and large transversal distances.

83 citations


Journal ArticleDOI
TL;DR: In this article, the authors investigated the mechanical properties of continuous carbon fiber-reinforced thermoplastic by testing composite specimens which were manufactured using an innovative process based on the fused filament fabrication (FFF), analogous to FDM®.
Abstract: The present work investigates the mechanical properties of continuous carbon fiber-reinforced thermoplastic by testing composite specimens which were manufactured using an innovative process based on the fused filament fabrication (FFF, analogous to FDM®). The adopted testing procedures and their results are presented, as well as an introduction to the manufacturing process, which is patented by Markforged Inc. The experimental mechanical properties (stiffness and strength) of the composite specimens, measured in tensile (longitudinal and transverse), compression (longitudinal) and in-plane shear are reported. The asymptotic homogenization technique is applied in order to predict the elastic mechanical properties of the carbon fiber-reinforced lamina. In contrast to recent studies, this investigation has revealed that considering Nylon as the thermoplastic matrix embedding the continuous fiber consistently underpredicts the transverse and in-plane shear elastic properties of the reinforced laminae. These results suggest that the composition of the thermoplastic resin is not exactly the same for the unreinforced and reinforced filaments. Additionally, cross-sectional micrographs of specimens are analyzed in detail and considerable insight has been gained concerning the thermoplastic resin of reinforced filaments.

71 citations


Journal ArticleDOI
TL;DR: In this article, the degradation rate of polylactic acid (PLA) implant was evaluated using in vitro simulated body fluid study, and the authors concluded the positive effect of process parameters on degradation rate and biocompatible behavior of PLA implant.
Abstract: Nowadays polylactic acid (PLA) is widely used in orthopedics surgeries as implants material due to well mechanical characterization and biomedical properties. But the PLA implants suffer from slow degradation rate when it is used in real-life scenario. In the present research work, the PLA specimens using additive manufacturing technique are fabricated and further assessed for mechanical characterization and its degradation behavior with different parameters. The change in weight of scaffolds was measured using digital weight measure, and pH value was measured using pH meter. Morphology and elemental composition of PLA scaffolds were characterized by SEM and EDS, respectively, while compressive strength is measured by the universal testing machine. Apatite formation and biocompatible nature of fabricated scaffolds were analyzed by in vitro simulated body fluid study. The outcomes of characterization exposed that scaffold with 60% infill percentage had maximum porosity, which is beneficial for the apatite formation and osseointegration. The average change in compressive strength was measured as 49.79 MPa after 14 days and 46.11 MPa after 28 days, whereas the average change in pH value was measured as 5.67 and 5.27 after 14 and 28 days of incubation period, respectively. The degradation rate of specimen 3 was 27.92% less than that of specimen 1, 35.69% less than that of specimen 5, and 87.98% more than that of specimen 9. This study concludes the positive effect of process parameters on degradation rate and biocompatible behavior of PLA implants.

70 citations


Journal ArticleDOI
TL;DR: In this article, the grey relational analysis (GRA) is used as an optimization tool to find out the suitable process parameters for the machining of carbon nanotube-reinforced carbon fiber nanocomposite.
Abstract: In this research work, the grey relational analysis (GRA) is used as an optimization tool to find out the suitable process parameters for the machining of carbon nanotube-reinforced carbon fibre nanocomposite. In discrete space degree of relation of different data sets analysed by GRA. In this experimental work, four process parameters are selected, namely peak current (Ip), pulse on time (Ton), duty cycle (η) and gap voltage (Vg), and the significant effect on material removal rate (MRR) and tool wear rate (TWR) has been calculated. Both are considered as the main input variables for the selection of suitable process parameters. Predicted process parameters by GRA show significant increment of 0.000003 in MRR and significant reduction of 0.001904 in TWR.

67 citations


Journal ArticleDOI
TL;DR: In this paper, the impact of nonlinear thermal radiation on heat transfer analysis of Carreau nanofluid flow through wedge by considering slip conditions into account is considered. And the results reveal that the temperature and concentration distributions both intensify with rising values of temperature slip parameter (ξ).
Abstract: In the present study, we have perceived the impact of nonlinear thermal radiation on heat transfer analysis of Carreau nanofluid flow through wedge by considering slip conditions into account. The extremely nonlinear partial differential equations are transformed into nonlinear ordinary differential equations by using suitable similarity variables, and these equations together with boundary conditions are solved by using the most extensively validated finite element method. The impact of various pertinent parameters, such as Weissenberg number, wedge angle parameter, radiation parameter, temperature ratio parameter, Prandtl number, thermophoresis parameter, Brownian motion parameter, constant velocity ratio parameter, suction parameter, temperature slip parameter, Lewis number, power law index parameter, concentration slip parameter, chemical reaction parameter and magnetic parameter, on velocity, temperature and concentration profiles is calculated and is revealed through graphs. The values of Nusselt number, Sherwood number and skin friction coefficient are also calculated and shown in tables. It is noticed that there is a remarkable intensification in the values of Nusselt number, Sherwood number and skin friction coefficient as the values of Weissenberg number rise. The temperature and concentration distributions both intensify with rising values of temperature slip parameter (ξ).

61 citations


Journal ArticleDOI
TL;DR: In this article, the authors investigate the heat and mass diffusion of upper convected Maxwell nanomaterials passed by a linear stretched surface (slip surface) near the stagnation point region.
Abstract: The aim of this article is to investigate the heat and mass diffusion (Cattaneo–Christov model) of the upper convected Maxwell nanomaterials passed by a linear stretched surface (slip surface) near the stagnation point region. Convocational Fourier’s and Fick’s laws are employed to investigate heat and mass diffusion phenomena. Using the similarity transformations, the governing PDEs are rendered into ODEs along with boundary conditions. The boundary value problem is solved numerically using RK-4 method along with shooting technique (Cash and Karp). The effects of embedded parameters, namely fluid relaxation parameter, Hartmann number, Brownian moment, thermophoresis parameter, thermal relaxation parameter, Lewis number, chemical reactions concentration relaxation parameter, and slip parameter on velocity, temperature, and concentration distributions, are deliberated through the graphs and discussed numerically. The skin friction coefficient is deliberated numerically, and their numerical values are accessible through graphs and table. The comparison of current article is calculated in the last section, and a good agreement is clear with the existing literature.

58 citations


Journal ArticleDOI
TL;DR: In this paper, the effect of cutting parameters and cooling/lubricating conditions on tool wear and surface roughness in the milling of nickel-based Waspaloy with ceramic tools was analyzed.
Abstract: Ceramic cutting tools are widely used particularly in high-speed machining of difficult-to-machine materials. However, using cutting fluid with these ceramic tools significantly reduces tool life. Therefore, the inclusion of a cooling/lubrication method into the process to improve the machining performance of ceramic tools will make machining efficiency much more effective. The aim of this study is to analyze the effect of cutting parameters and cooling/lubricating conditions on tool wear and surface roughness in the milling of nickel-based Waspaloy with ceramic tools. The cutting tools selected for the study were Ti[C, N]-mixed alumina inserts (CC650), SiC whisker-reinforced alumina inserts (CC670) and alumina and SiAlON ceramic inserts (CC6060). The machining parameters comprised three different cooling/lubricating methods (dry, wet and MQL), three different cutting speeds (500, 600 and 700 m/min) and three different feed rates (0.02, 0.04 and 0.06 mm/rev). Analysis of variance was used to determine the effects of the machining parameters on tool wear and surface roughness. In addition, a regression analysis was conducted to identify the relationship between the dependent and independent variables. According to the experimental results, the minimum quantity lubrication method was identified as the best cooling method for minimum tool wear and surface roughness. In terms of ceramic grades, the SiAlON inserts provided better results in all experimental trials. The dominant wear types observed in all cutting tools were flank wear and notch wear.

56 citations


Journal ArticleDOI
TL;DR: In this paper, the thermal effects of magnetohydrodynamic micropolar fluid with hidden phenomenon of heat and mass transfer via Caputo-Fabrizio fractional derivative were investigated.
Abstract: This paper investigates the thermal effects of magnetohydrodynamic micropolar fluid with hidden phenomenon of heat and mass transfer via Caputo–Fabrizio fractional derivative. Analytical solutions are obtained for velocity field, mass concentration, microrotation and temperature distribution by implementing Fourier Sine and Laplace transform. The general solutions have been expressed in terms of simple elementary functions involving the convolution theorem for the Laplace transform. The graphical illustration is depicted in order to explore the influence of rheological parameters, i.e., Grashof, Prandtl, Schmidt numbers, transverse magnetic field, microrotation parameter, porosity and few other parameters on micropolar fluid flow.

Journal ArticleDOI
TL;DR: In this paper, a mathematical model is developed to investigate the electroosmotic flow of pseudoplastic aqueous nanoliquids in microchannel, where a tangent hyperbolic fluid model is employed to describe the rheological behavior of the pseudplastic fluid and analytical solutions for potential distribution, temperature and nanoparticle fraction are derived and perturbation solution for stream function, pressure gradient and volumetric flow rate are obtained.
Abstract: The study of electroosmotic flow of biorheological fluids has been employed in the advancement of diversified biomicrofluidics systems. To explore more in this field, a mathematical model is developed to investigate the electroosmotic flow of pseudoplastic aqueous nanoliquids in microchannel. A tangent hyperbolic fluid model is employed to describe the rheological behavior of the pseudoplastic fluid. Here, analytical solutions for potential distribution, temperature and nanoparticle fraction are derived and perturbation solution for stream function, pressure gradient and volumetric flow rate are obtained. The convective boundary condition is applied on the channel walls. The authentic assumptions of Debye–Huckel linearization, long wavelength and small Reynold’s number are employed in the dimensional conservative equations. The influences of various emerging parameters are graphically computed for axial velocity, pressure gradient, thermal temperature, nanoparticle volume fraction, skin friction coefficient and Nusselt profiles. To observe the thermal radiation effects, a thermal radiative flux model is also deployed. It is noticed that the heat transfer Biot number increases with increasing thermal temperature; however, a reversed behavior is reported for the nanoparticle volume fraction. Therefore, the present model does not only provide a deep theoretical insight to interpret the electroosmotic flow systems, but it will also be applicable in designing the emerging tool for biomicrofluidic devices/systems under peristalsis mechanisms.

Journal ArticleDOI
TL;DR: In this article, a higher-order shear deformation shell theory and the Bi-Helmholtz nonlocal strain gradient theory are used to model the nanoshell as a continuum model and predicting the size-dependent behavior.
Abstract: Elastic bulk wave characteristics of doubly curved nanoshell made of functionally graded (FG) anisotropic material are studied. The effective properties of FG anisotropic material vary along the thickness direction. A higher-order shear deformation shell theory and the Bi-Helmholtz nonlocal strain gradient theory are, respectively, utilized to model the nanoshell as a continuum model and predicting the size-dependent behavior. The Hamiltonian principle is adopted to obtain the governing equations of wave motion. These equations are solved analytically to evaluate the wave characteristics of the nanoshell. Emphasizing the effect of parametric excitation, the influences of small-scale parameters, exponential factor, magnetic field intensity, initial stress, elastic foundation parameters, and wave number are assessed on the wave dispersion response of FG anisotropic nanoshell.

Journal ArticleDOI
TL;DR: A literature review on the diversity of conventional and non-conventional materials that are used or have potential to be used as EDM electrodes is presented in this paper, where additive manufacturing of EDM electrode is also reviewed.
Abstract: Over the years, sinking electrical discharge machining has become one of the most important production technologies to manufacture very accurate three-dimensional complex components on any electrically conductive material. This article reports a literature review on the diversity of conventional and non-conventional materials that are used or have potential to be used as EDM electrodes. In addition, additive manufacturing of EDM electrodes are also reviewed.

Journal ArticleDOI
TL;DR: In this paper, the authors formulated a CuO-H2O nanoliquid flow with wavy circular cylinder as heater subjected to magnetohydrodynamics and derived a novel correlation regarding average Nusselt number subject to analysis's active parameters.
Abstract: Researchers have a wide-ranging tradition in endeavoring to rise the thermophysical aspects of convection heat transferors for illustration, transformer oil and water. Technological advancements in recent years permit the dispersal of elements having ranges between 10 and 100 nm in such liquids. Recent researches regarding nanoliquids have been elaborated to exhibit anomalously higher convection heat transportation. Keeping such implications in mind, we formulated CuO-H2O nanoliquid flow with wavy circular cylinder as heater subjected to magnetohydrodynamics. The well-known Darcy model featuring porous medium along with KKL (Koo–Kleinstreuer–Li) model is considered simultaneously for analysis. Heat transportation is reported considering radiation effect. The impact of shape factor of nanoparticles is also considered. Simulations are presented employing the novel control volume finite element method. The influences of notable parameters like Darcy number, Rayleigh and Hartmann numbers, radiation parameter, amplitude of undulations, nanofluid volume fraction and shape factor of nanoparticles have been investigated on flow and heat transfer features. Moreover, a novel correlation regarding average Nusselt number has been developed subject to analysis’s active parameters. Our outcomes report that lower values of amplitude of undulations provide the uppermost estimations of average Nusselt number.

Journal ArticleDOI
TL;DR: In this article, hybrid polymer composites of epoxy (E) reinforced with sisal (SF), banana (BF), coir (CF), and sisal/banana/coir (SBCF) fibers were fabricated by compression molding process.
Abstract: Recently, polymer composite materials are the most widely used elements in engineering applications. In this work, hybrid polymer composites of epoxy (E) reinforced with sisal (SF), banana (BF), coir (CF) and sisal/banana/coir (SBCF) fibers were fabricated by compression molding process. Five different kinds of laminates were prepared in the following stacking sequence of E, E/SF, E/BF, E/CF and E/SBCF of 30% SF,BF, CF with 70% of E and 10% of each fiber with 70% of E. Mechanical properties like tensile, flexural, impact and hardness strength in addition to water absorption test were evaluated and compared. Interfacial analysis was also carried out with the help of scanning electron microscope to study the micro-structural behavior of the tested specimen. The chemical formation of the new polymer composites and hybrid polymer composites was analyzed by means of Fourier-transform infrared spectroscopy technique additionally. The mechanical results showed that among these polymer composites, E/SF polymer composites were found to possess enhanced strength.

Journal ArticleDOI
TL;DR: In this article, the impacts of compliant wall and variable liquid properties on the peristaltic stream of a Rabinowitsch liquid in an inclined channel were analyzed graphically.
Abstract: The present paper emphasizes the impacts of the compliant wall and variable liquid properties on the peristaltic stream of a Rabinowitsch liquid in an inclined channel. The viscosity of the liquid differs over the thickness of the channel, and temperature-dependent thermal conductivity is considered. The perturbation strategy is utilized to solve the governing nonlinear temperature equations. The expressions for the velocity, skin friction coefficient, pressure rise, frictional force, streamline, temperature and coefficient of heat transfer are obtained. The consequences of pertinent parameters on the velocity, temperature, streamline and coefficient of heat transfer for the dilatant, Newtonian and pseudoplastic liquid models are analysed graphically. The results obtained for velocity and temperature reveal that an expansion in the estimation of variable viscosity results in diminishing the velocity and temperature fields for shear thickening liquid. Furthermore, it is noticed that for a large value of thermal conductivity the temperature profile decreases for dilatant, Newtonian and pseudoplastic fluid models.

Journal ArticleDOI
TL;DR: In this paper, the effects of different cutting parameters, such as cutting speed (30, 60, and 90 m/min), feed (0.05, 0.1, and 0.3 m/rev), and depth of cut ( 0.5, and 1.5 m/mm), as well as cutting tool geometry such as the cutting tool nose radius, and cutting tool coating (coated and uncoated) on the cutting force, maximum cutting temperature, surface microstructure, and surface residual stresses during cutting AISI 1035 alloy steel.
Abstract: Residual stresses (RSes) induced by turning processes have a great effect on the material properties of the machined components and their abilities to withstand severe loading conditions (creep, fatigue, and stress corrosion cracking). The final state of RSes in a workpiece depends on its material and on the employed cutting parameters/conditions such as cutting speed, depth of cut, feed speed, cutting tool geometry, wear of the tool, cutting tool geometry, cutting tool coating, and cooling. This study introduces a comprehensive investigation of the effects of different cutting parameters, such as cutting speed (30, 60, and 90 m/min), feed (0.05, 0.1, and 0.3 mm/rev), and depth of cut (0.1, 0.5, and 1 mm) as well as cutting tool geometry such as cutting tool nose radius (0.397, 0.794, and 1.191 mm), and cutting tool coating (coated and uncoated) on the cutting force, maximum cutting temperature, surface microstructure, and surface residual stresses during cutting AISI 1035 alloy steel. The RSes were measured using X-ray diffraction technique. The experiments were designed using Taguchi method based on L18 orthogonal array, and the significance level of different cutting parameters as well as cutting tool properties have been determined via applying analysis of variance. Numerical simulations have been carried out using commercial machining software AdvantEdge.

Journal ArticleDOI
TL;DR: In this article, the effect of cryogenic liquid carbon dioxide (−79.5 °C) on the machining of Nimonic 80A was investigated using PVD-TiAlN coated tungsten carbide (WC) insert.
Abstract: Alloys of nickel are optimal metals to use in turbine parts and aircraft components. They are generally accepted as difficult-to-machine materials, because of its poor thermal conductivity. The selection of coolant and machining conditions is crucial for better performance. Problems with conventional coolant are failure of lubrication at higher metal removal and cause environmental pollution. The heat produced at the cutting zone can shorten the life of the tool, which leads to dimensional imprecision. The current experimental investigation is machining of Nimonic 80A under the effect of cryogenic liquid carbon dioxide (− 79.5 °C) using PVD-TiAlN coated tungsten carbide (WC) insert, which is compared with conventional dry, flood, and MQL environments. The machining is carried at varying cutting speed ranging from 45 to 90 m/min, a feed rate of 0.06–0.08 mm/tooth, and a constant depth of cut of 0.75 mm. The results admitted that cryogenic cooling lessens the average roughness by 42–47% over dry cutting, 24–27% over wet cutting, and 16–21% over MQL. It is proved that cryogenic cooling produces greater compressive stress on the machined surface and brings down the flank wear by decreasing the temperature on the cutting zone.

Journal ArticleDOI
TL;DR: Research results indicate that the proposed method for effective signal component extraction can adaptively acquire effective signal components with higher accuracy and is more efficient in the extraction of effective components from complex signal.
Abstract: Data processing is widely used to extract effective component from original signal, which is essential in mechanical condition monitoring and fault diagnosis. In order to solve the invalid component and non-stationary feature in the measured signal, the extraction method for effective signal component is proposed based on extreme-point symmetric mode decomposition (ESMD) and Kullback–Leibler (K–L) divergence. This method fully integrates the characteristics of ESMD in self-adaptive decomposition and the advantages of K–L divergence in measuring the distance between different signals. The effective and invalid components of non-stationary signal are automatically separated by ESMD, and the effective components are further identified through K–L divergence calculation. Some analyses of simulated data and experimental data were investigated. And the effect of the proposed method in effective component extraction was emphatically explored. Research results indicate that the proposed method can adaptively acquire effective signal components with higher accuracy. Moreover, compared with the classic method, it is more efficient in the extraction of effective components from complex signal. In addition, this research solves the interference problem of invalid signals and accurately reconstructs the desired useful signal.

Journal ArticleDOI
TL;DR: In this paper, multi-walled carbon nanotube (MWCNT) dispersed into kerosene is explored as dielectric media to improve EDM performance on Inconel 718 superalloy.
Abstract: Electro-discharge machining (EDM) is very promising non-traditional machining route to cut ‘difficult-to-machine’ materials like Inconel 718 superalloy. However, low material removal efficiency and inferior surface integrity restricts EDM application on Inconel 718. In order to improve EDM performance, multi-walled carbon nanotube (MWCNT) dispersed into kerosene is explored as dielectric media. Experiments are conducted by varying peak discharge current with a fixed concentration of MWCNT (0.5 g/l) added to kerosene. EDM performance is assessed in purview of material removal efficiency, tool wear rate, and surface integrity (morphology and topography) of the EDMed specimen. Apart from morphological study, surface topography including surface roughness, crack density, recast layer thickness, metallographic alteration, residual stress, and micro-indentation hardness of the machined specimen are studied in detail. It is concluded that as compared to conventional EDM, use of MWCNT-mixed dielectric media (0.5 g/l) significantly improves machining performance.

Journal ArticleDOI
TL;DR: In this paper, the effect of variable thermal conductivity and thermal radiation on the magnetohydrodynamic tangent hyperbolic fluid in the presence of nanoparticles past a stretching sheet is scrutinized.
Abstract: The forthright intention of this communication is to scrutinize the effect of variable thermal conductivity and thermal radiation on the magnetohydrodynamic tangent hyperbolic fluid in the presence of nanoparticles past a stretching sheet. For heat and mass transport phenomena, the collective stimulus of slip and convective conditions with the internal heating, viscous dissipation and Joule heating have been taken into account. The boundary layer equations of two-dimensional tangent hyperbolic nanofluid have been established with the help of boundary layer approximations. With the assistance of appropriate similarity transformation, the governing set of PDEs are rendered into the coupled nonlinear ODEs. The solution of the resulting ODEs is obtained with the help of the shooting technique. Furthermore, an authentication of the computed results is obtained through benchmark with the previously reported cases. The influence of various pertinent parameters on the velocity, temperature and concentration profiles has been analyzed graphically and discussed. The physical behavior of the velocity, temperature concentration, skin friction coefficient, the Nusselt and the Sherwood numbers have been investigated diagrammatically for various pertinent parameters. It is observed that the velocity profile is declined for the growing values of the Weissenberg number and the power law index, whereas the thermal and concentration fields are observed to enhanced for the same parameters. Our analysis depicts that the temperature and the concentration profiles are enhanced for the slip parameter and the Eckert number.

Journal ArticleDOI
TL;DR: In this article, the authors evaluated the shear strength of battery tab-to-tab joints for both similar and dissimilar materials by using combinations of aluminium (Al) and nickel-coated copper (Cu[Ni]) tabs.
Abstract: Lithium-ion-based secondary battery packs are emerging as an alternative power source and are being increasingly used in electric vehicles, hybrid or plug-in hybrid electric vehicles. Typically, a standard automotive battery pack consists of hundreds, even thousands, of individual cells which are connected in series and/or parallel to deliver the required power and capacity. There is an increasing need for manufacturing of battery packs to meet the demand reflecting the uptake of these vehicles. This triggers the need for suitable joining methods which will provide mechanical strength on a par with electrical and thermal characteristics. This work focuses on characterisation of shear strength of battery tab-to-tab joints for both similar and dissimilar materials by using combinations of aluminium (Al) and nickel-coated copper (Cu[Ni]) tabs. The joining techniques with application for battery tab interconnects are ultrasonic metal welding, resistance spot welding and pulsed TIG spot welding. Lap shear and T-peel tests are performed to evaluate the joint strength. In general, lap shear strength is four to seven times higher than the T-peel strength obtained from all three joining methods. In addition, an indicator is developed in this paper based on lap shear-to-T-peel strength reduction ratio which provides additional information on joint strength characteristics, and subsequently, it can be used as a threshold by quality engineers for an indication on selection of joining methods having an acceptable strength reduction ratio.

Journal ArticleDOI
TL;DR: In this paper, the cervical canal is approximated as a two-dimensional complex wavy channel inclined at a certain angle with the horizontal and the velocity of the microswimmer is calculated by using the built-in bvp4c function.
Abstract: The efficient magnetic swimming of actual or mechanically designed microswimmers within bounded regions is reliant on several factors: the actuation of these swimmers via magnetic field, rheology of surrounding liquid (with dominant viscous forces), nature of medium (either porous or non-porous), position (either straight, inclined or declined) and state (either active or passive) of the narrow passage. To witness these interactions, we utilize Carreau fluid with Taylor swimming sheet model under magnetic and porous effects. Moreover, the cervical canal is approximated as a two-dimensional complex wavy channel inclined at certain angle with the horizontal. The momentum equations are reduced by means of lubrication assumption, which finally leads to a fourth-order differential equation. MATLAB’s built-in bvp4c function is employed to solve the resulting boundary value problem. The solution obtained via bvp4c is further verified by finite difference method. In both these methods, the refined values of flow rate and cell speed are computed by utilizing modified Newton–Raphson method. These realistic pairs are further utilized to calculate the energy delivered by the microswimmer. The numerical results are plotted and discussed at the end of the article. Our study explains that the optimum speed of the microorganism can be achieved by means of exploiting the fluid rheology and with the suitable application of the magnetic field. The peristaltic nature of the channel walls and porous medium may also serve as alternative factors to control the speed of the propeller.

Journal ArticleDOI
TL;DR: The current state of the art of the ISF process has been discussed with detailed analysis of process capabilities and limitations in terms of forming forces, and a lack of focus was found on effects of some important forming process parameters and methods which could have been crucial for safe utilization of forming hardware.
Abstract: Incremental sheet forming (ISF) significantly exempts use of expensive dies and reduces tooling cost for manufacturing complex parts in the field of sheet metal forming which makes it suitable for manufacturing prototypes and low volume production as compared to other traditional sheet metal forming processes. ISF also finds suitability for producing components of old machinery, which are otherwise very difficult to form due to the unavailability of forming dies. Moreover, the incremental nature of the process and local deformation of the sheet ensures higher formability and lower required forming force. To take advantages of lower required forming force, it is important to minimize and estimate forming force through the manipulation of the parameters for the safe utilization of hardware. In this review article, a literature survey was carried out quantitatively to study different aspects of ISF, especially to show different process parameters and techniques that affect the forming forces significantly. The current state of the art of the ISF process has been discussed with detailed analysis of process capabilities and limitations in terms of forming forces. Influences of different process parameters and forming techniques have also been studied on forming forces. Some parameters have shown their significance to control the forming force in order to preserve forming machinery. A lack of focus was found on effects of some important forming process parameters and methods, which could have been crucial for safe utilization of forming hardware. A number of guidelines have been recommended for future research work. Appropriate guidelines have also been suggested regarding the relationship between process parameters and forming forces developed during the process in order to ensure the applicability of the ISF process on the industrial scale.

Journal ArticleDOI
TL;DR: In this article, the impact of using nanoparticle minimum quantity lubrication (NMQL) on the performance of uncoated carbide textured tools in turning hardened steel was investigated.
Abstract: Present investigation is focused to study the impact of different lubricating environments using pure canola oil and graphene mixed in canola oil, on the performance of uncoated carbide textured tools in minimum quantity lubrication (MQL) turning of AISI 4340 hardened steel. The influence of using twin jet and single jet was also studied under MQL. The turning performance was evaluated in terms of flank wear (VBmax), cutting forces, cutting temperature, and chip morphology. The results showed that MQL mist supplied simultaneously on rake and flank face of the textured tool by twin-jet nozzle performed better than MQL mist supplied on the rake face of textured tool by the single-jet nozzle. Out of all the tested lubricating environments, best tool life was achieved with nanoparticle minimum quantity lubrication (NMQL) using the twin jet followed by only oil using twin jet as compared to all other conditions tested in this study. The outcome of the study illustrates that MQL mist of graphene which is mixed in canola oil on a textured tool with the twin-jet nozzle can be successfully applied for finish turning of hardened steel.

Journal ArticleDOI
TL;DR: In this paper, the association between Brazilian ethanol and advanced technology in internal combustion engine (ICE) is presented as a promising alternative for a more sustainable global mobility in the future, and environmental, social, ethical and economic impacts arising from electric vehicles are investigated, demystifying the zero-emission vehicle terminology attributed to them.
Abstract: The sustainable future of mobility should not be viewed as the burial of the internal combustion engine (ICE), nowadays the main source of vehicular propulsion. Even with the increasing electrification of the transport means, the low global percentage of the electric fleet, around 0.2% of the total road vehicles, associated with an annual growth rate of less than 60%, indicates that they will not significantly change the market share in the short- and medium-term periods. This means that fuel demanded by ICEs and pollutant emissions generated by them will be very relevant in the years to come. Thus, the search for significant advances in technology associated with the use of renewable fuels is very important for environmental and economic sustainability. In this regard, the present work intends to demonstrate that the association between Brazilian ethanol and advanced technology in ICEs is a promising alternative for a more sustainable global mobility in the future. For this purpose, some ethanol properties are presented to justify its relevance as an ideal biofuel for highly boosted and efficient engines. Then, environmental, social, ethical and economic impacts arising from electric vehicles are investigated, demystifying the zero-emission vehicle terminology attributed to them and, finally, new technologies for ICEs are presented, proving that they are constantly evolving and improving, which is fundamental to the future of the world automotive fleet.

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TL;DR: In this paper, the flow and heat transfer of MHD Eyring-Powell fluid in a circular infinite pipe is discussed, where the rheology of fluid is described by constitutive equation of Eyring and Powell fluid and the solution is constructed for both constant and variable viscosity cases.
Abstract: In the current study, the flow and heat transfer of MHD Eyring–Powell fluid in a circular infinite pipe is discussed. The rheology of fluid is described by constitutive equation of Eyring–Powell fluid. The solution is constructed for both constant and variable viscosity cases. For variable viscosity case, the viscosity function is defined by Reynolds and Vogel’s models. The solution of each case is calculated numerically with the help of eminent iterative numerical technique. The effects of thermo-fluidic parameters on flow and heat transfer phenomenon are highlighted through graphs. The velocity and temperature profiles diminish against magnetic parameter $$(M_{e} )$$ and material parameter (M) in all cases, whereas both velocity and temperature profiles rise via magnitude of the pressure gradient and material parameter Y. The validity of our numerical results due to shooting method is presented by comparing them with the numerical results produced by pseudo-spectral collocation method. Relative absolute errors are plotted, and achieved accuracies are of the order four and five in w and $$\theta$$, respectively. The outcomes of current investigation may be useful in thin film, catalytic reactors, polymer solutions and paper production, etc.

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TL;DR: In this article, an analytical solution for the temperature distribution and velocity field of gas flow based on sine and cosine sinusoidal waves, and these are expressed in terms of elementary functions are presented through graphical illustrations.
Abstract: Several industrial manufacturing processes mostly depend upon measurement of gases for controlling the product quality, process control, environmental compliance and production efficiencies. We propose here unsteady natural convection radiating flow as an application of gas flow measurement through mathematical modeling based on governing fractional differential equations. The mathematical model of unsteady natural convection radiating flow is analyzed by Fourier sine and Laplace transform with novel analytical calculations and results. From the analysis of mathematical point of view, the main novelty of considered technique is fractional approach of Atangana–Baleanu which provides non-singular effect of gas with Mittag–Leffler kernel, promising straightforward convergence of imposed initial and boundary conditions that is not assumed for perturbation and discretization. The analytical solutions are obtained for the temperature distribution and velocity field of gas flow based on sine and cosine sinusoidal waves, and these are expressed in terms of elementary functions. Finally, in order to meet the physical aspects of the problem, the multiple variations and differential parametric analysis have been presented through graphical illustrations.

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TL;DR: In this article, the wear mechanisms of aluminium alloy (AA5083) composites reinforced with boron carbide (B4C) particles having 300-mesh size were investigated.
Abstract: Aluminium alloy is known to be a soft material with inadequate hardness, poor wear resistance and good castability; in order to improve its wear resistance, numerous researches have been conducted. This paper deals with the wear mechanisms of aluminium alloy (AA5083) composites reinforced with boron carbide (B4C) particles having 300 mesh size. The fabrication of aluminium metal matrix composite specimen by varying boron carbide in 5%, 10%, 15% and 20% of the weight of aluminium alloy was produced (composite-A, composite-B, composite-C and composite-D, respectively) by the stir-casting technique. The wear mechanisms of the developed metal matrix composites were studied at various parameters such as sliding distance (1000 m, 2000 m and 3000 m), load (30 N, 40 N and 50 N) and sliding velocity (1 m/s, 2 m/s and 3 m/s). The wear mechanisms of the prepared specimen (composites-A, B, C and D) were compared with each other under the same experimental condition on the pin-on-disc wear machine. The major findings in this paper are: the better wear resistance property of the developed metal matrix composites than that of the alloy used as matrix, the wear of composite has been linear and effortless prediction of the wear characteristics by the researchers.