Pub Date : 2023-02-01DOI: 10.1108/mmms-08-2022-0158
A. Habib, U. Yildirim
PurposeOver the past few decades, several base isolation systems have been developed to enhance the performance of structures under extreme earthquake shaking intensities. Recently, to achieve high energy dissipation capabilities, a new generation of multi-stage friction pendulum (FP) bearings known as the “Quintuple Friction Pendulum (QFP)” was introduced in the literature. With the help of its five effective pendula and nine operational regimes, this bearing's major benefits stem from its ability to accomplish complicated multi-stage adaptive behavior with smoothed loading and unloading when subjected to lateral forces.Design/methodology/approachWithin the assessment context, five finite element models of reinforced concrete frames supported on QFP isolators with different properties will be developed in OpenSees. Thereafter, a set of 60 earthquakes will be analyzed using the nonlinear time history analysis approach, and the impact of each ground motion record's properties will be evaluated.FindingsOverall, the study's findings have demonstrated that the characteristics of the isolator, combined with the type of earthquake being applied, have a substantial impact on the isolator's behavior.Originality/valueCurrently, no studies have examined the energy distribution of structural systems equipped with this type of isolation system while considering the influence of earthquake characteristics. Thus, this study is intended to extend the findings available in the literature by discussing and illustrating the distribution of strong ground motions input energy into highly nonlinear base-isolated systems that account for the bearing and superstructural materials' nonlinearity, geometric nonlinearity and leakage-prevented viscous damping nonlinearity. Besides, it investigates the influence of various earthquake characteristics on the energy dissipation of such buildings.
{"title":"Distribution of strong input energy in base-isolated structures with complex nonlinearity: a parametric assessment","authors":"A. Habib, U. Yildirim","doi":"10.1108/mmms-08-2022-0158","DOIUrl":"https://doi.org/10.1108/mmms-08-2022-0158","url":null,"abstract":"PurposeOver the past few decades, several base isolation systems have been developed to enhance the performance of structures under extreme earthquake shaking intensities. Recently, to achieve high energy dissipation capabilities, a new generation of multi-stage friction pendulum (FP) bearings known as the “Quintuple Friction Pendulum (QFP)” was introduced in the literature. With the help of its five effective pendula and nine operational regimes, this bearing's major benefits stem from its ability to accomplish complicated multi-stage adaptive behavior with smoothed loading and unloading when subjected to lateral forces.Design/methodology/approachWithin the assessment context, five finite element models of reinforced concrete frames supported on QFP isolators with different properties will be developed in OpenSees. Thereafter, a set of 60 earthquakes will be analyzed using the nonlinear time history analysis approach, and the impact of each ground motion record's properties will be evaluated.FindingsOverall, the study's findings have demonstrated that the characteristics of the isolator, combined with the type of earthquake being applied, have a substantial impact on the isolator's behavior.Originality/valueCurrently, no studies have examined the energy distribution of structural systems equipped with this type of isolation system while considering the influence of earthquake characteristics. Thus, this study is intended to extend the findings available in the literature by discussing and illustrating the distribution of strong ground motions input energy into highly nonlinear base-isolated systems that account for the bearing and superstructural materials' nonlinearity, geometric nonlinearity and leakage-prevented viscous damping nonlinearity. Besides, it investigates the influence of various earthquake characteristics on the energy dissipation of such buildings.","PeriodicalId":46760,"journal":{"name":"Multidiscipline Modeling in Materials and Structures","volume":null,"pages":null},"PeriodicalIF":2.0,"publicationDate":"2023-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46399565","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-01-26DOI: 10.1108/mmms-09-2022-0197
Royal Madan, Shubhankar Bhowmick, L. Hadji, A. Alnujaie
PurposeIn this work, the effect of porosity volume fraction, porosity types, material grading index, variable disk profiles and aspect ratio on disk performance was studied by performing limit elastic speed analysis of functionally graded porous rotating disks (PFGM) under thermo-mechanical loading.Design/methodology/approachThe composition change was varied by employing the power law function. The thermo-mechanical properties of PFGM such as Young's modulus and yield strength were estimated using modified rule of mixture, for density and coefficient of thermal expansion rule of mixture was used. The even and uneven distribution of porosity in a disk was taken as uniform, symmetrical, inner maximum and outer maximum. The problem was then solved with the help of the variational principle and Galerkin's error minimization theory.FindingsThe research reveals that the grading parameter, disk geometry and porosity distribution have a significant impact on the limit elastic speed in comparison to the aspect ratio.Practical implicationsThe study determines a range of operable speeds for porous and non-porous disk profiles that the industry can utilize to estimate structural performance.Originality/valueA finite element investigation was conducted to validate the findings of the present study. Limit elastic analysis of porous FG disks under thermo-mechanical loading has not been studied before.
{"title":"Limit angular speed analysis of porous functionally graded rotating disk under thermo-mechanical loading","authors":"Royal Madan, Shubhankar Bhowmick, L. Hadji, A. Alnujaie","doi":"10.1108/mmms-09-2022-0197","DOIUrl":"https://doi.org/10.1108/mmms-09-2022-0197","url":null,"abstract":"PurposeIn this work, the effect of porosity volume fraction, porosity types, material grading index, variable disk profiles and aspect ratio on disk performance was studied by performing limit elastic speed analysis of functionally graded porous rotating disks (PFGM) under thermo-mechanical loading.Design/methodology/approachThe composition change was varied by employing the power law function. The thermo-mechanical properties of PFGM such as Young's modulus and yield strength were estimated using modified rule of mixture, for density and coefficient of thermal expansion rule of mixture was used. The even and uneven distribution of porosity in a disk was taken as uniform, symmetrical, inner maximum and outer maximum. The problem was then solved with the help of the variational principle and Galerkin's error minimization theory.FindingsThe research reveals that the grading parameter, disk geometry and porosity distribution have a significant impact on the limit elastic speed in comparison to the aspect ratio.Practical implicationsThe study determines a range of operable speeds for porous and non-porous disk profiles that the industry can utilize to estimate structural performance.Originality/valueA finite element investigation was conducted to validate the findings of the present study. Limit elastic analysis of porous FG disks under thermo-mechanical loading has not been studied before.","PeriodicalId":46760,"journal":{"name":"Multidiscipline Modeling in Materials and Structures","volume":null,"pages":null},"PeriodicalIF":2.0,"publicationDate":"2023-01-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47292435","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-01-26DOI: 10.1108/mmms-09-2022-0200
Rajib Gope, M. Nayak, S. Shaw, S. Mondal
PurposeThe major goal of this article is to investigate flow and thermal aspects of Oldroyd B with hybrid nanostructure subject to a radially stretched surface under the influence of low and moderate Prandtl numbers.Design/methodology/approachThe non-dimensional governing equations are solved considering BVP4C in MATLAB as instrumental.FindingsEntropy generation effect is analyzed. Radial velocity and entropy generation exhibit opposite effect in response to amplified relaxation and retardation time parameters in case of both low and moderate Prandtl numbers. Augmented relaxation and retardation time parameters controls heat transfer rate.The results show that increasing the aspect ratio increases both the average Nusselt and entropy generation numbers for each value of the Prandtl number, while increasing the prandtl number decreases both. There is also a minimum value for the entropy generation number at a given relaxation and retardation parameter.Research limitations/implicationsAssume that the Oldroyd B fluid is dispersed with hybrid nanostructure in order to ameliorate thermal conductivity of Oldroyd B fluid so as to make it as best coolant.Practical implicationsThe low range of Prandtl number comprising particles of air, gas, etc. and moderate range of Prandtl number comprising particles of honey, thin motor oil, or any non-Newtonian liquid. The hybrid nanofluid is radiative in nature. Also, the effects of significant physical parameters on entropy generation are highlighted. The entropy generation number intensifies due to the rise in temperature difference parameter at low/moderate Prandtl number effectively. Entropy minimization can lead to the amelioration of available energy thereby enhances the efficiency of several thermal systems.Originality/valueThis article's primary goal is to investigate the flow and thermal aspects of Oldroyd B with a hybrid nanostructure subject to a radially stretched surface under the influence of low and moderate Prandtl numbers.
{"title":"Hydro-thermo-fluidic aspects of Oldroyd B fluid with hybrid nanostructure subject to low and moderate Prandtl numbers","authors":"Rajib Gope, M. Nayak, S. Shaw, S. Mondal","doi":"10.1108/mmms-09-2022-0200","DOIUrl":"https://doi.org/10.1108/mmms-09-2022-0200","url":null,"abstract":"PurposeThe major goal of this article is to investigate flow and thermal aspects of Oldroyd B with hybrid nanostructure subject to a radially stretched surface under the influence of low and moderate Prandtl numbers.Design/methodology/approachThe non-dimensional governing equations are solved considering BVP4C in MATLAB as instrumental.FindingsEntropy generation effect is analyzed. Radial velocity and entropy generation exhibit opposite effect in response to amplified relaxation and retardation time parameters in case of both low and moderate Prandtl numbers. Augmented relaxation and retardation time parameters controls heat transfer rate.The results show that increasing the aspect ratio increases both the average Nusselt and entropy generation numbers for each value of the Prandtl number, while increasing the prandtl number decreases both. There is also a minimum value for the entropy generation number at a given relaxation and retardation parameter.Research limitations/implicationsAssume that the Oldroyd B fluid is dispersed with hybrid nanostructure in order to ameliorate thermal conductivity of Oldroyd B fluid so as to make it as best coolant.Practical implicationsThe low range of Prandtl number comprising particles of air, gas, etc. and moderate range of Prandtl number comprising particles of honey, thin motor oil, or any non-Newtonian liquid. The hybrid nanofluid is radiative in nature. Also, the effects of significant physical parameters on entropy generation are highlighted. The entropy generation number intensifies due to the rise in temperature difference parameter at low/moderate Prandtl number effectively. Entropy minimization can lead to the amelioration of available energy thereby enhances the efficiency of several thermal systems.Originality/valueThis article's primary goal is to investigate the flow and thermal aspects of Oldroyd B with a hybrid nanostructure subject to a radially stretched surface under the influence of low and moderate Prandtl numbers.","PeriodicalId":46760,"journal":{"name":"Multidiscipline Modeling in Materials and Structures","volume":null,"pages":null},"PeriodicalIF":2.0,"publicationDate":"2023-01-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48000960","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-01-25DOI: 10.1108/mmms-07-2022-0139
Ranjan Kumar, S. Chaterjee, V. Ranjan, S. Ghoshal
PurposeThe present findings report a significant influence of disc profile and thickness on the order of excitation leading to critical speed condition. Certain transverse modes of vibration of the disc have been obtained to be more susceptible to get excited while recording the lowest critical speeds.Design/methodology/approachNumerical simulation using finite-element method has been adopted due to the complicated geometry, complex loadings and intricate analytical formulation. A comprehensive analysis of exclusive as well as combination of thermal and centrifugal loads has been taken up to determine the intensity and characteristics of the individual/combined effects.FindingsThe typical gas turbine disc profile has been analyzed to predict the critical speed under the factual working condition of an aero-engine. FEM analysis of uniform and variable thickness discs have been carried out under stationary, rotating and rotating-thermal considerations while emphasizing the effect of disc profile and thickness. Centrifugal stresses developed due to rotational effect result in unceasing stiffening of the discs with higher stiffening for a greater number of nodal diameters. On the other hand, a role reversal of thermal effect from stiffening to softening is figured out with increasing numbers of nodal diameters. However, the discs are subjected to an overall stiffening effect on account of the combined centrifugal and thermal loading, with the effect decreasing with an increase in disc thickness. Under the combined loading, the order of excitation leading to critical speed condition is dependent on disc profile and thickness. Moreover, the vibrational modes (0,1) and (0,2) are identified as more prominent adverse modes corresponding to lowest critical speeds.Practical implicationsThe present findings are expected to serve as guidelines during the design phase of gas turbine discs of aeroengine applications.Originality/valueThe present work deliberates on the simulation and analysis of gas turbine disc specific to aeroengine application. The real-life disc geometry has been analyzed with due consideration of major factual operating conditions to identify the critical speed. The identification of various critical speed using numerical analysis can help to reduce the number of experimental tests required for certification.
{"title":"Simulation studies on combined effect of variable geometry, rotation and temperature gradient on critical speed of gas turbine disc","authors":"Ranjan Kumar, S. Chaterjee, V. Ranjan, S. Ghoshal","doi":"10.1108/mmms-07-2022-0139","DOIUrl":"https://doi.org/10.1108/mmms-07-2022-0139","url":null,"abstract":"PurposeThe present findings report a significant influence of disc profile and thickness on the order of excitation leading to critical speed condition. Certain transverse modes of vibration of the disc have been obtained to be more susceptible to get excited while recording the lowest critical speeds.Design/methodology/approachNumerical simulation using finite-element method has been adopted due to the complicated geometry, complex loadings and intricate analytical formulation. A comprehensive analysis of exclusive as well as combination of thermal and centrifugal loads has been taken up to determine the intensity and characteristics of the individual/combined effects.FindingsThe typical gas turbine disc profile has been analyzed to predict the critical speed under the factual working condition of an aero-engine. FEM analysis of uniform and variable thickness discs have been carried out under stationary, rotating and rotating-thermal considerations while emphasizing the effect of disc profile and thickness. Centrifugal stresses developed due to rotational effect result in unceasing stiffening of the discs with higher stiffening for a greater number of nodal diameters. On the other hand, a role reversal of thermal effect from stiffening to softening is figured out with increasing numbers of nodal diameters. However, the discs are subjected to an overall stiffening effect on account of the combined centrifugal and thermal loading, with the effect decreasing with an increase in disc thickness. Under the combined loading, the order of excitation leading to critical speed condition is dependent on disc profile and thickness. Moreover, the vibrational modes (0,1) and (0,2) are identified as more prominent adverse modes corresponding to lowest critical speeds.Practical implicationsThe present findings are expected to serve as guidelines during the design phase of gas turbine discs of aeroengine applications.Originality/valueThe present work deliberates on the simulation and analysis of gas turbine disc specific to aeroengine application. The real-life disc geometry has been analyzed with due consideration of major factual operating conditions to identify the critical speed. The identification of various critical speed using numerical analysis can help to reduce the number of experimental tests required for certification.","PeriodicalId":46760,"journal":{"name":"Multidiscipline Modeling in Materials and Structures","volume":null,"pages":null},"PeriodicalIF":2.0,"publicationDate":"2023-01-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46002716","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-01-23DOI: 10.1108/mmms-06-2022-0102
E. Pankratov
PurposeThe purpose of this paper is (1) to analyze the dependence of charge carriers mobility in an implanted-junction heterorectifier on mismatch-induced stress and (2) to elaborate an analytical approach for analysis of mass transfer with the possibility to take into account changing of parameters of mass transport in space and time at one time as well as nonlinearity of the considered transfer.Design/methodology/approachIn this paper, the author analyzed charge carriers mobility changing in an implanted-junction heterorectifier under the influence of mismatch-induced stress. The author introduced a model to describe the considered changing of carriers mobility. Based on the analysis of the model, the author formulated conditions (1) to decrease and to increase of the mobility under influence of the stress; and (2) the author analyzed the possibility to control of mismatch-induced stress by radiation processing of materials of the considered multilayer structure. The author also introduced an analytical approach for analysis of mass transfer. The approach gives a possibility to take into account changing of parameters of mass transport in space and time at one time as well as nonlinearity of the considered transfer.FindingsFindings dependence of charge carriers mobility in an implanted-junction heterorectifier on mismatch-induced stress. Also the author finds an analytical approach for analysis of mass transfer. The approach gives a possibility to take into account changing of parameters of mass transport in space and time at one time as well as nonlinearity of the considered transfer.Originality/valueAll results of this paper are original.
{"title":"A model of changing of charge carriers mobility value in an implanted-junction rectifier under influence of mismatch-induced stress","authors":"E. Pankratov","doi":"10.1108/mmms-06-2022-0102","DOIUrl":"https://doi.org/10.1108/mmms-06-2022-0102","url":null,"abstract":"PurposeThe purpose of this paper is (1) to analyze the dependence of charge carriers mobility in an implanted-junction heterorectifier on mismatch-induced stress and (2) to elaborate an analytical approach for analysis of mass transfer with the possibility to take into account changing of parameters of mass transport in space and time at one time as well as nonlinearity of the considered transfer.Design/methodology/approachIn this paper, the author analyzed charge carriers mobility changing in an implanted-junction heterorectifier under the influence of mismatch-induced stress. The author introduced a model to describe the considered changing of carriers mobility. Based on the analysis of the model, the author formulated conditions (1) to decrease and to increase of the mobility under influence of the stress; and (2) the author analyzed the possibility to control of mismatch-induced stress by radiation processing of materials of the considered multilayer structure. The author also introduced an analytical approach for analysis of mass transfer. The approach gives a possibility to take into account changing of parameters of mass transport in space and time at one time as well as nonlinearity of the considered transfer.FindingsFindings dependence of charge carriers mobility in an implanted-junction heterorectifier on mismatch-induced stress. Also the author finds an analytical approach for analysis of mass transfer. The approach gives a possibility to take into account changing of parameters of mass transport in space and time at one time as well as nonlinearity of the considered transfer.Originality/valueAll results of this paper are original.","PeriodicalId":46760,"journal":{"name":"Multidiscipline Modeling in Materials and Structures","volume":null,"pages":null},"PeriodicalIF":2.0,"publicationDate":"2023-01-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42258934","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-01-10DOI: 10.1108/mmms-08-2022-0164
D. Sheoran, Komal Yadav, Baljit Singh Punia, K. K. Kalkal
PurposeThe purpose of this paper is to analyse the transient effects in a functionally graded photo-thermoelastic (TE) medium with gravity and rotation by considering two generalised TE theories: Lord–Shulman (LS) and Green–Lindsay (GL). The governing equations are derived in rectangular Cartesian coordinates for a two dimensional problem.Design/methodology/approachAll the physical properties of the semiconductor are supposed to vary exponentially with distance. The analytical solution is procured by employing normal mode technique on the resulting non-dimensional coupled field equations with appropriate boundary conditions.FindingsFor the mechanically loaded thermally insulated surface, normal displacement, stress components, temperature distribution and carrier density are calculated numerically with the help of MATLAB software for a silicon semiconductor and displayed graphically. Some particular cases of interest have also been deduced from the present results.Originality/valueThe effects of rotation and non-homogeneity on the different physical fields are investigated on the basis of analytical and numerical results. Comparisons are made with the results predicted by GL theory in the presence and absence of gravity for different values of time. Comparisons are also made between the three theories in the presence of rotation, gravity and in-homogeneity. Such problems are very important in many dynamical systems.
{"title":"Thermodynamical interactions in a rotating functionally graded semiconductor material with gravity","authors":"D. Sheoran, Komal Yadav, Baljit Singh Punia, K. K. Kalkal","doi":"10.1108/mmms-08-2022-0164","DOIUrl":"https://doi.org/10.1108/mmms-08-2022-0164","url":null,"abstract":"PurposeThe purpose of this paper is to analyse the transient effects in a functionally graded photo-thermoelastic (TE) medium with gravity and rotation by considering two generalised TE theories: Lord–Shulman (LS) and Green–Lindsay (GL). The governing equations are derived in rectangular Cartesian coordinates for a two dimensional problem.Design/methodology/approachAll the physical properties of the semiconductor are supposed to vary exponentially with distance. The analytical solution is procured by employing normal mode technique on the resulting non-dimensional coupled field equations with appropriate boundary conditions.FindingsFor the mechanically loaded thermally insulated surface, normal displacement, stress components, temperature distribution and carrier density are calculated numerically with the help of MATLAB software for a silicon semiconductor and displayed graphically. Some particular cases of interest have also been deduced from the present results.Originality/valueThe effects of rotation and non-homogeneity on the different physical fields are investigated on the basis of analytical and numerical results. Comparisons are made with the results predicted by GL theory in the presence and absence of gravity for different values of time. Comparisons are also made between the three theories in the presence of rotation, gravity and in-homogeneity. Such problems are very important in many dynamical systems.","PeriodicalId":46760,"journal":{"name":"Multidiscipline Modeling in Materials and Structures","volume":null,"pages":null},"PeriodicalIF":2.0,"publicationDate":"2023-01-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45714345","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-01-05DOI: 10.1108/mmms-08-2022-0163
S. Desai, Mangalsing Narsing Sonare
PurposeThe prediction of critical velocity at instability threshold for shell and tube heat exchangers is important to avoid failure of tubes as a result of flow-induced vibrations due to water cross flow. The flow-induced vibration in finned tube heat exchangers is affected by various parameters such as fin height, fin pitch, fin material, tube array, pitch ratio, fin type, fluid velocity etc. In this paper, an experimental investigation of fluid elastic instability in shell and tube heat exchangers is carried out by subjecting normal square finned tube arrays of pitch ratio 1.79 to water cross flow.Design/methodology/approachThe five tube arrays, namely plain array, two finned tube arrays with 3 fpi and 9 fpi fin density, and two finned tube arrays with 3 mm and 6 mm fin height are tested in the experimental test setup with water flow loop and vibration measurement system. The research objective is to evaluate the effect of fin density and fin height on the instability threshold. The critical velocity at instability threshold is determined to characterize the fluid elastic instability behavior of different tube arrays. The vortex shedding behavior of the tube arrays is also studied by determining Strouhal number corresponding to the small peaks before fluid elastic instability.FindingsThe fluid elastic instability behavior of the tube arrays was found to be the function of fin tube parameters. The experimental results indicate that an increase in fin density and fin height results in delaying the instability threshold for finned tube arrays. It is also observed that critical velocity at instability is increased for finned tube arrays compared to plain tube arrays of the same pitch ratio. The design modifications in the outer box have resulted in further reduction in the natural frequency. This enabled to reach clear instability for all the five-tube arrays.Originality/valueThe research data add the value to the present body of knowledge by knowing the effect of fin height and fin density on the fluid elastic instability threshold of normal square finned tube arrays subjected to water cross flow.
{"title":"Effect of fin density and fin height on flow-induced vibration behavior of finned tube arrays subjected to water cross flow","authors":"S. Desai, Mangalsing Narsing Sonare","doi":"10.1108/mmms-08-2022-0163","DOIUrl":"https://doi.org/10.1108/mmms-08-2022-0163","url":null,"abstract":"PurposeThe prediction of critical velocity at instability threshold for shell and tube heat exchangers is important to avoid failure of tubes as a result of flow-induced vibrations due to water cross flow. The flow-induced vibration in finned tube heat exchangers is affected by various parameters such as fin height, fin pitch, fin material, tube array, pitch ratio, fin type, fluid velocity etc. In this paper, an experimental investigation of fluid elastic instability in shell and tube heat exchangers is carried out by subjecting normal square finned tube arrays of pitch ratio 1.79 to water cross flow.Design/methodology/approachThe five tube arrays, namely plain array, two finned tube arrays with 3 fpi and 9 fpi fin density, and two finned tube arrays with 3 mm and 6 mm fin height are tested in the experimental test setup with water flow loop and vibration measurement system. The research objective is to evaluate the effect of fin density and fin height on the instability threshold. The critical velocity at instability threshold is determined to characterize the fluid elastic instability behavior of different tube arrays. The vortex shedding behavior of the tube arrays is also studied by determining Strouhal number corresponding to the small peaks before fluid elastic instability.FindingsThe fluid elastic instability behavior of the tube arrays was found to be the function of fin tube parameters. The experimental results indicate that an increase in fin density and fin height results in delaying the instability threshold for finned tube arrays. It is also observed that critical velocity at instability is increased for finned tube arrays compared to plain tube arrays of the same pitch ratio. The design modifications in the outer box have resulted in further reduction in the natural frequency. This enabled to reach clear instability for all the five-tube arrays.Originality/valueThe research data add the value to the present body of knowledge by knowing the effect of fin height and fin density on the fluid elastic instability threshold of normal square finned tube arrays subjected to water cross flow.","PeriodicalId":46760,"journal":{"name":"Multidiscipline Modeling in Materials and Structures","volume":null,"pages":null},"PeriodicalIF":2.0,"publicationDate":"2023-01-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45630090","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-01-03DOI: 10.1108/mmms-08-2022-0160
N. Vijay, K. Sharma
PurposeThe investigation of fluid flow over a rotating disk has been increasing due to the spread of machine technology. Because of this development, we scrutinized the Magnetohydrodynamic (MHD) flow of hybrid nanofluid caused by a decelerating rotating disk with Ohmic heating, Soret and Dufour effects. The disk's angular velocity is taken to be an inversely time-dependent linear function. Moreover, the temperature-dependent viscosity of hybrid nanofluid is incorporated in the present investigation. Methanol is considered as base fluid, while copper oxide (CuO) and magnesium oxide (MgO) are nanoparticles.Design/methodology/approachEstimated fundamental partial differential equations of flow problems are altered as a dimensionless system of ordinary differential equations using appropriate similarity transformation and solved using a numerical technique: BVP Midrich scheme in Maple software. The impression of emerging non-dimensional parameters is portrayed graphically. All outcomes are shown in the velocity, temperature and concentration profiles.FindingsThe developed flow problem involves a non-dimensional parameter (A) that reveals the deceleration of the disk. For larger values of A, the disk decelerates faster and for some fixed time, the fluid surrounding the disk revolves more rapidly than the disk itself. The radial velocity of fluid diminishes and axial velocity becomes uniform when the disk is subjected to wall suction velocity (B).Originality/valueThis analysis is significant in biomedical engineering, cancer therapeutic, manufacturing industries and nano-drug suspension in pharmaceuticals. The novelty of the current study is the hybrid nanofluid flow with Ohmic heating, Soret and Dufour effects on a decelerating rotating disk. To the best of the author's knowledge, no such consideration has been published in the literature.
{"title":"Magnetohydrodynamic hybrid nanofluid flow over a decelerating rotating disk with Soret and Dufour effects","authors":"N. Vijay, K. Sharma","doi":"10.1108/mmms-08-2022-0160","DOIUrl":"https://doi.org/10.1108/mmms-08-2022-0160","url":null,"abstract":"PurposeThe investigation of fluid flow over a rotating disk has been increasing due to the spread of machine technology. Because of this development, we scrutinized the Magnetohydrodynamic (MHD) flow of hybrid nanofluid caused by a decelerating rotating disk with Ohmic heating, Soret and Dufour effects. The disk's angular velocity is taken to be an inversely time-dependent linear function. Moreover, the temperature-dependent viscosity of hybrid nanofluid is incorporated in the present investigation. Methanol is considered as base fluid, while copper oxide (CuO) and magnesium oxide (MgO) are nanoparticles.Design/methodology/approachEstimated fundamental partial differential equations of flow problems are altered as a dimensionless system of ordinary differential equations using appropriate similarity transformation and solved using a numerical technique: BVP Midrich scheme in Maple software. The impression of emerging non-dimensional parameters is portrayed graphically. All outcomes are shown in the velocity, temperature and concentration profiles.FindingsThe developed flow problem involves a non-dimensional parameter (A) that reveals the deceleration of the disk. For larger values of A, the disk decelerates faster and for some fixed time, the fluid surrounding the disk revolves more rapidly than the disk itself. The radial velocity of fluid diminishes and axial velocity becomes uniform when the disk is subjected to wall suction velocity (B).Originality/valueThis analysis is significant in biomedical engineering, cancer therapeutic, manufacturing industries and nano-drug suspension in pharmaceuticals. The novelty of the current study is the hybrid nanofluid flow with Ohmic heating, Soret and Dufour effects on a decelerating rotating disk. To the best of the author's knowledge, no such consideration has been published in the literature.","PeriodicalId":46760,"journal":{"name":"Multidiscipline Modeling in Materials and Structures","volume":null,"pages":null},"PeriodicalIF":2.0,"publicationDate":"2023-01-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42569286","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-01-02DOI: 10.1108/mmms-07-2022-0120
Parvinder Kaur, Surjan Singh
PurposeIn this paper, temperature distribution and fin efficiency in a moving porous fin have been discussed. The heat transfer equation is formulated by using Darcy's model. Heat transfer coefficient and thermal conductivity vary with temperature. The surface emissivity of the fin varies with temperature as well as with wavelength. Thermal conductivity is taken as a linear and quadratic form of temperature. The entire analysis of the paper is presented in non-dimensional form.Design/methodology/approachIn this study, a new mathematical model is investigated. The novelty of this model is surface emissivity which is considered temperature and wavelength dependent. Another interesting point is the addition of porous material. The Legendre wavelet collocation method has been used to solve the nonlinear heat transfer equation. Numerical simulations are carried out in MATLAB software.FindingsAn attempt has been made to discuss temperature distribution in the presence of porosity and wavelength-temperature-dependent surface emissivity. The effect of various parameters on temperature has been discussed, including thermal conductivity, emissivity, convection-radiation, Peclet number, sink temperature, exponent “n” and porosity. Fin efficiency is also calculated for some parameters. According to the study, heat transfer rate increases with higher radiation-convection, emissivity, wavelength and porosity parameters.Originality/valueThe numerical results are carried out by using the Legendre wavelet collocation method, which has been compared with exact results in a particular case and found to be in good agreement. The percent error is calculated to find the error between the current method and the exact result. A comparison of the obtained results with the previous data is presented to validate the numerical results.
{"title":"Convective-radiative moving porous fin with temperature-dependent thermal conductivity, heat transfer coefficient and wavelength-dependent surface emissivity","authors":"Parvinder Kaur, Surjan Singh","doi":"10.1108/mmms-07-2022-0120","DOIUrl":"https://doi.org/10.1108/mmms-07-2022-0120","url":null,"abstract":"PurposeIn this paper, temperature distribution and fin efficiency in a moving porous fin have been discussed. The heat transfer equation is formulated by using Darcy's model. Heat transfer coefficient and thermal conductivity vary with temperature. The surface emissivity of the fin varies with temperature as well as with wavelength. Thermal conductivity is taken as a linear and quadratic form of temperature. The entire analysis of the paper is presented in non-dimensional form.Design/methodology/approachIn this study, a new mathematical model is investigated. The novelty of this model is surface emissivity which is considered temperature and wavelength dependent. Another interesting point is the addition of porous material. The Legendre wavelet collocation method has been used to solve the nonlinear heat transfer equation. Numerical simulations are carried out in MATLAB software.FindingsAn attempt has been made to discuss temperature distribution in the presence of porosity and wavelength-temperature-dependent surface emissivity. The effect of various parameters on temperature has been discussed, including thermal conductivity, emissivity, convection-radiation, Peclet number, sink temperature, exponent “n” and porosity. Fin efficiency is also calculated for some parameters. According to the study, heat transfer rate increases with higher radiation-convection, emissivity, wavelength and porosity parameters.Originality/valueThe numerical results are carried out by using the Legendre wavelet collocation method, which has been compared with exact results in a particular case and found to be in good agreement. The percent error is calculated to find the error between the current method and the exact result. A comparison of the obtained results with the previous data is presented to validate the numerical results.","PeriodicalId":46760,"journal":{"name":"Multidiscipline Modeling in Materials and Structures","volume":null,"pages":null},"PeriodicalIF":2.0,"publicationDate":"2023-01-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44273236","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-12-30DOI: 10.1108/mmms-09-2022-0195
Aishwarya Narang, Ravi Kumar, A. Dhiman
PurposeThis study seeks to understand the connection of methodology by finding relevant papers and their full review using the “Preferred Reporting Items for Systematic Reviews and Meta-Analyses” (PRISMA).Design/methodology/approachConcrete-filled steel tubular (CFST) columns have gained popularity in construction in recent decades as they offer the benefit of constituent materials and cost-effectiveness. Artificial Neural Networks (ANNs), Support Vector Machines (SVMs), Gene Expression Programming (GEP) and Decision Trees (DTs) are some of the approaches that have been widely used in recent decades in structural engineering to construct predictive models, resulting in effective and accurate decision making. Despite the fact that there are numerous research studies on the various parameters that influence the axial compression capacity (ACC) of CFST columns, there is no systematic review of these Machine Learning methods.FindingsThe implications of a variety of structural characteristics on machine learning performance parameters are addressed and reviewed. The comparison analysis of current design codes and machine learning tools to predict the performance of CFST columns is summarized. The discussion results indicate that machine learning tools better understand complex datasets and intricate testing designs.Originality/valueThis study examines machine learning techniques for forecasting the axial bearing capacity of concrete-filled steel tubular (CFST) columns. This paper also highlights the drawbacks of utilizing existing techniques to build CFST columns, and the benefits of Machine Learning approaches over them. This article attempts to introduce beginners and experienced professionals to various research trajectories.
{"title":"Machine learning applications to predict the axial compression capacity of concrete filled steel tubular columns: a systematic review","authors":"Aishwarya Narang, Ravi Kumar, A. Dhiman","doi":"10.1108/mmms-09-2022-0195","DOIUrl":"https://doi.org/10.1108/mmms-09-2022-0195","url":null,"abstract":"PurposeThis study seeks to understand the connection of methodology by finding relevant papers and their full review using the “Preferred Reporting Items for Systematic Reviews and Meta-Analyses” (PRISMA).Design/methodology/approachConcrete-filled steel tubular (CFST) columns have gained popularity in construction in recent decades as they offer the benefit of constituent materials and cost-effectiveness. Artificial Neural Networks (ANNs), Support Vector Machines (SVMs), Gene Expression Programming (GEP) and Decision Trees (DTs) are some of the approaches that have been widely used in recent decades in structural engineering to construct predictive models, resulting in effective and accurate decision making. Despite the fact that there are numerous research studies on the various parameters that influence the axial compression capacity (ACC) of CFST columns, there is no systematic review of these Machine Learning methods.FindingsThe implications of a variety of structural characteristics on machine learning performance parameters are addressed and reviewed. The comparison analysis of current design codes and machine learning tools to predict the performance of CFST columns is summarized. The discussion results indicate that machine learning tools better understand complex datasets and intricate testing designs.Originality/valueThis study examines machine learning techniques for forecasting the axial bearing capacity of concrete-filled steel tubular (CFST) columns. This paper also highlights the drawbacks of utilizing existing techniques to build CFST columns, and the benefits of Machine Learning approaches over them. This article attempts to introduce beginners and experienced professionals to various research trajectories.","PeriodicalId":46760,"journal":{"name":"Multidiscipline Modeling in Materials and Structures","volume":null,"pages":null},"PeriodicalIF":2.0,"publicationDate":"2022-12-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44272543","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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