Pub Date : 2023-10-19DOI: 10.1080/15502287.2023.2268096
S. Hariharan, Amit Varakhedkar, Rajendran Senthil Kumar
AbstractThe rapid increase in technologies, especially computer chips, increases the demand for highly efficient thermal management systems. The present study carries out a two-dimensional numerical investigation on the effect of the number of sides of a heated cylinder in a highly confined fluid domain. The flow is confined to a blockage ratio of 3. The study is conducted for laminar flow with Reynolds numbers being 50, 100, 150 and 200. Six cylinders are chosen; Square, pentagon, hexagon, circle, dodecagon and hexa-decogan. The simulation is carried out using ANSYS FLUENT 18. SIMPLE algorithm is used to solve the Navier–Stokes equation. The flow and heat transfer characteristics are studied from pressure and temperature contour, viscous drag co-efficient, pressure-drag coefficient, total drag co-efficient, pressure co-efficient, Strouhal number and Nusselt number. As the number of sides increased, a significant difference in flow and heat transfer characteristics is observed at the starting, but all slowly started to converge toward the characteristics of the circular cylinder. The dodecagon cylinder shows better flow and heat transfer performance on average when compared to all the other cylinders.Keywords: Various types of cylinderstotal-drag coefficientStrouhal numberNusselt number AcknowledgementWe sincerely thank the Computational Fluid Dynamics Lab and Product Development Lab at the Department of Mechanical Engineering, SRM Institute of Science and Technology for allowing us to use the facilities for the computational analysis.Disclosure statementNo potential conflict of interest was reported by the authors.
{"title":"Effect of multiple sides of heated bluff body and heat transfer in a confined region: a computational study","authors":"S. Hariharan, Amit Varakhedkar, Rajendran Senthil Kumar","doi":"10.1080/15502287.2023.2268096","DOIUrl":"https://doi.org/10.1080/15502287.2023.2268096","url":null,"abstract":"AbstractThe rapid increase in technologies, especially computer chips, increases the demand for highly efficient thermal management systems. The present study carries out a two-dimensional numerical investigation on the effect of the number of sides of a heated cylinder in a highly confined fluid domain. The flow is confined to a blockage ratio of 3. The study is conducted for laminar flow with Reynolds numbers being 50, 100, 150 and 200. Six cylinders are chosen; Square, pentagon, hexagon, circle, dodecagon and hexa-decogan. The simulation is carried out using ANSYS FLUENT 18. SIMPLE algorithm is used to solve the Navier–Stokes equation. The flow and heat transfer characteristics are studied from pressure and temperature contour, viscous drag co-efficient, pressure-drag coefficient, total drag co-efficient, pressure co-efficient, Strouhal number and Nusselt number. As the number of sides increased, a significant difference in flow and heat transfer characteristics is observed at the starting, but all slowly started to converge toward the characteristics of the circular cylinder. The dodecagon cylinder shows better flow and heat transfer performance on average when compared to all the other cylinders.Keywords: Various types of cylinderstotal-drag coefficientStrouhal numberNusselt number AcknowledgementWe sincerely thank the Computational Fluid Dynamics Lab and Product Development Lab at the Department of Mechanical Engineering, SRM Institute of Science and Technology for allowing us to use the facilities for the computational analysis.Disclosure statementNo potential conflict of interest was reported by the authors.","PeriodicalId":315058,"journal":{"name":"International Journal for Computational Methods in Engineering Science and Mechanics","volume":"142 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135730365","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
AbstractIn the present work, a hybrid finite difference scheme is proposed and tested for the study of two-dimensional detonation problems. The hybrid scheme consists of a fifth-order weighted essentially nonoscillatory (WENO) method for discontinuous regions and a fourth or sixth-order robust conservative central finite difference scheme for the remaining domain. An arbitrary shock sensor is used to identify the discontinuities. The proposed shock sensor is based on the absolute value of the density gradient with an arbitrary threshold computed at each time step using a fast image segmentation technique. The sensor is complemented with a Ducros sensor to avoid the selection of vortices as discontinuities. The hybrid scheme is tested for several benchmark examples, including a two-dimensional transverse detonation wave, detonation wave diffraction, and a multiple obstacles test case. The obtained results show that the proposed sensor detects discontinuities adequately and the hybrid schemes give the same results as the fifth-order WENO in faster computational time.Keywords: WENOcentral finite differencefinite difference methodRunge-Kuttadetonationhybrid schemereactive Euler equationsshock sensor Disclosure statementNo potential conflict of interest was reported by the authors.
{"title":"Hybrid conservative central/WENO finite difference scheme for two-dimensional detonation problems","authors":"Nasreddine Bouguellab, Smail Khalfallah, Boubakr Zebiri, Nassim Brahmi","doi":"10.1080/15502287.2023.2268062","DOIUrl":"https://doi.org/10.1080/15502287.2023.2268062","url":null,"abstract":"AbstractIn the present work, a hybrid finite difference scheme is proposed and tested for the study of two-dimensional detonation problems. The hybrid scheme consists of a fifth-order weighted essentially nonoscillatory (WENO) method for discontinuous regions and a fourth or sixth-order robust conservative central finite difference scheme for the remaining domain. An arbitrary shock sensor is used to identify the discontinuities. The proposed shock sensor is based on the absolute value of the density gradient with an arbitrary threshold computed at each time step using a fast image segmentation technique. The sensor is complemented with a Ducros sensor to avoid the selection of vortices as discontinuities. The hybrid scheme is tested for several benchmark examples, including a two-dimensional transverse detonation wave, detonation wave diffraction, and a multiple obstacles test case. The obtained results show that the proposed sensor detects discontinuities adequately and the hybrid schemes give the same results as the fifth-order WENO in faster computational time.Keywords: WENOcentral finite differencefinite difference methodRunge-Kuttadetonationhybrid schemereactive Euler equationsshock sensor Disclosure statementNo potential conflict of interest was reported by the authors.","PeriodicalId":315058,"journal":{"name":"International Journal for Computational Methods in Engineering Science and Mechanics","volume":"249 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136113214","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-10-09DOI: 10.1080/15502287.2023.2265357
Jia Zhang, Yongbin Ma
AbstractIn this paper, based on fractional order strain theory and nonlocal heat conduction theory, the thermoelastic response of an elastic rod rigidly fixed at both ends and subjected to a moving heat source is investigated. The nonlocal fractional order strain control equation is established, and the analytical expressions of dimensionless temperature, displacement, and stress are solved using the Laplace integral transformation and numerical inverse transformation. The distribution law of physical quantities such as temperature, displacement, and stress when the fractional parameters, heat source moving speed, and thermal nonlocal parameters change is obtained. The results show that strain parameters and thermal nonlocal parameters have less influence on thermal–mechanical waves, while heat source velocity has a significant influence on thermal–mechanical waves.Keywords: Fractional order strainnonlocal thermal effectsmoving heat sourceLaplace transformthermoelastic response Disclosure statementNo potential conflict of interest was reported by the authors.Additional informationFundingThis work was supported by the National Natural Science Foundation of China [12062011 and 11972176].
{"title":"Thermoelastic response of an elastic rod under the action of a moving heat source based on fractional order strain theory considering nonlocal effects","authors":"Jia Zhang, Yongbin Ma","doi":"10.1080/15502287.2023.2265357","DOIUrl":"https://doi.org/10.1080/15502287.2023.2265357","url":null,"abstract":"AbstractIn this paper, based on fractional order strain theory and nonlocal heat conduction theory, the thermoelastic response of an elastic rod rigidly fixed at both ends and subjected to a moving heat source is investigated. The nonlocal fractional order strain control equation is established, and the analytical expressions of dimensionless temperature, displacement, and stress are solved using the Laplace integral transformation and numerical inverse transformation. The distribution law of physical quantities such as temperature, displacement, and stress when the fractional parameters, heat source moving speed, and thermal nonlocal parameters change is obtained. The results show that strain parameters and thermal nonlocal parameters have less influence on thermal–mechanical waves, while heat source velocity has a significant influence on thermal–mechanical waves.Keywords: Fractional order strainnonlocal thermal effectsmoving heat sourceLaplace transformthermoelastic response Disclosure statementNo potential conflict of interest was reported by the authors.Additional informationFundingThis work was supported by the National Natural Science Foundation of China [12062011 and 11972176].","PeriodicalId":315058,"journal":{"name":"International Journal for Computational Methods in Engineering Science and Mechanics","volume":"9 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135141953","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-10-04DOI: 10.1080/15502287.2023.2261258
Pooja Raj Verma, Monika Meena, Nirmal Yadav
AbstractA strip-saturation model is studied to observe the effect of changing polarization axis on an electro-elastic strip, weakened by an eccentrically situated anti-plane semipermeable crack. The model is modified by considering that the saturated limit of electric displacement over rims of the saturation zone is quadratic interpolating polynomial times. The proposed model is formulated and then solved by using the Fourier integral transform technique and integral equations method. Closed-form analytic expressions are derived for developed saturation zone and fracture parameters viz. electric crack condition parameter, crack-sliding displacement, crack-opening potential drop, field intensity factors, energy release rate, etc. The influence of poling angle, prescribed electro-mechanical loadings, crack length, and material constants on fracture parameters are presented and analyzed graphically.Keywords: Eccentric crackelectro-elastic stripFourier transformintegral transform techniquemodified strip-saturation modelpoling directionsemi-permeable crack Disclosure statementAll authors declare that they have no conflict of interest.Additional informationFundingThis study is not funded by any agency.
{"title":"Strip-saturation model for arbitrary polarized electro-elastic material weakened by an eccentrically situated anti-plane semi-permeable crack","authors":"Pooja Raj Verma, Monika Meena, Nirmal Yadav","doi":"10.1080/15502287.2023.2261258","DOIUrl":"https://doi.org/10.1080/15502287.2023.2261258","url":null,"abstract":"AbstractA strip-saturation model is studied to observe the effect of changing polarization axis on an electro-elastic strip, weakened by an eccentrically situated anti-plane semipermeable crack. The model is modified by considering that the saturated limit of electric displacement over rims of the saturation zone is quadratic interpolating polynomial times. The proposed model is formulated and then solved by using the Fourier integral transform technique and integral equations method. Closed-form analytic expressions are derived for developed saturation zone and fracture parameters viz. electric crack condition parameter, crack-sliding displacement, crack-opening potential drop, field intensity factors, energy release rate, etc. The influence of poling angle, prescribed electro-mechanical loadings, crack length, and material constants on fracture parameters are presented and analyzed graphically.Keywords: Eccentric crackelectro-elastic stripFourier transformintegral transform techniquemodified strip-saturation modelpoling directionsemi-permeable crack Disclosure statementAll authors declare that they have no conflict of interest.Additional informationFundingThis study is not funded by any agency.","PeriodicalId":315058,"journal":{"name":"International Journal for Computational Methods in Engineering Science and Mechanics","volume":"10 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135591159","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-09-04DOI: 10.1080/15502287.2023.2253255
F. Berntsson, Patrik Wikström
Abstract Temperature control is important for the steel making process. Knowledge of the amount of thermal energy stored in the ladle allows for better predictions of the steel temperature during the process. This has a potential to improve the quality of the steel. In this work, we present a mathematical model of the heat transfer within a ladle during the production process. The model can be used to compute the current, and also the future, thermal status of the ladle. The model is simple and can be solved efficiently. We also present results from numerical simulations intended to illustrate the model.
{"title":"Thermal tracking of a ladle during production cycles","authors":"F. Berntsson, Patrik Wikström","doi":"10.1080/15502287.2023.2253255","DOIUrl":"https://doi.org/10.1080/15502287.2023.2253255","url":null,"abstract":"Abstract Temperature control is important for the steel making process. Knowledge of the amount of thermal energy stored in the ladle allows for better predictions of the steel temperature during the process. This has a potential to improve the quality of the steel. In this work, we present a mathematical model of the heat transfer within a ladle during the production process. The model can be used to compute the current, and also the future, thermal status of the ladle. The model is simple and can be solved efficiently. We also present results from numerical simulations intended to illustrate the model.","PeriodicalId":315058,"journal":{"name":"International Journal for Computational Methods in Engineering Science and Mechanics","volume":"76 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126227822","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-05-27DOI: 10.1080/15502287.2023.2211985
M. Ferdows, Tahia Tazin, O. Bég, T. Bég, Kadir Ali
Abstract A theoretical study is presented for the steady magnetohydrodynamic (MHD) boundary layer stagnation point flow of a nano-ferrofluid along a linearly moving stretching sheet, as a simulation of functional magnetic materials processing. Due to having imerging applications in heat transfer, the nano-ferrofluids draw the attention which comprise an aqueous base fluid doped with a variety of magnetic nanoparticles, i.e. magnetite (Fe3O4), cobalt ferrite (CoFe2O4) and Manganese-zinc (Mn-Zn) ferrite. A partial differential equation mathematical model is developed for mass, momentum, magnetic field continuity (induction), and energy with appropriate wall and free stream boundary conditions. Following similarity transformations, the dimensionless resultant nonlinear ordinary differential boundary value problem is solved numerically using the robust bvp4c function in MATLAB which features very efficient 4th order optimized Runge–Kutta quadrature. Dual solutions for the upper branch and lower branch separated by a critical point are identified. Visualization of velocity, temperature, and induced magnetic field function are presented graphically including validation of solutions with previous studies. Furthermore, skin-friction coefficient and the local Nusselt number are also computed. The impact of the controlling parameters, i.e. Prandtl number nanoparticle volume fraction parameter reciprocal of magnetic Prandtl number magnetic parameter and stretching rate ratio parameter have been illustrated through graphs and evaluated when a desire heat transfer can occur. Furthermore, resistance between fluid and the plate can be increased with the growing magnetic Prandtl number values. Increment in magnetic parameter ( ) produces an elevation in the induced magnetic field magnitudes. Skin friction and Nusselt number are found to be greater for cobalt nanoparticles when compared to magnetite and Mn-Zn ferromagnetic nanoparticles when there is an increase in reciprocal magnetic Prandtl number. The simulations provide a deeper insight into the manufacturing flows of functional nano-ferromagnetic materials of relevance to deposition and coating systems.
{"title":"Dual solutions of magnetite/cobalt/manganese-zinc-aqueous nano-ferrofluids from a stretching sheet with magnetic induction effects: MHD stagnation flow computation and analysis","authors":"M. Ferdows, Tahia Tazin, O. Bég, T. Bég, Kadir Ali","doi":"10.1080/15502287.2023.2211985","DOIUrl":"https://doi.org/10.1080/15502287.2023.2211985","url":null,"abstract":"Abstract A theoretical study is presented for the steady magnetohydrodynamic (MHD) boundary layer stagnation point flow of a nano-ferrofluid along a linearly moving stretching sheet, as a simulation of functional magnetic materials processing. Due to having imerging applications in heat transfer, the nano-ferrofluids draw the attention which comprise an aqueous base fluid doped with a variety of magnetic nanoparticles, i.e. magnetite (Fe3O4), cobalt ferrite (CoFe2O4) and Manganese-zinc (Mn-Zn) ferrite. A partial differential equation mathematical model is developed for mass, momentum, magnetic field continuity (induction), and energy with appropriate wall and free stream boundary conditions. Following similarity transformations, the dimensionless resultant nonlinear ordinary differential boundary value problem is solved numerically using the robust bvp4c function in MATLAB which features very efficient 4th order optimized Runge–Kutta quadrature. Dual solutions for the upper branch and lower branch separated by a critical point are identified. Visualization of velocity, temperature, and induced magnetic field function are presented graphically including validation of solutions with previous studies. Furthermore, skin-friction coefficient and the local Nusselt number are also computed. The impact of the controlling parameters, i.e. Prandtl number nanoparticle volume fraction parameter reciprocal of magnetic Prandtl number magnetic parameter and stretching rate ratio parameter have been illustrated through graphs and evaluated when a desire heat transfer can occur. Furthermore, resistance between fluid and the plate can be increased with the growing magnetic Prandtl number values. Increment in magnetic parameter ( ) produces an elevation in the induced magnetic field magnitudes. Skin friction and Nusselt number are found to be greater for cobalt nanoparticles when compared to magnetite and Mn-Zn ferromagnetic nanoparticles when there is an increase in reciprocal magnetic Prandtl number. The simulations provide a deeper insight into the manufacturing flows of functional nano-ferromagnetic materials of relevance to deposition and coating systems.","PeriodicalId":315058,"journal":{"name":"International Journal for Computational Methods in Engineering Science and Mechanics","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-05-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114766745","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-05-22DOI: 10.1080/15502287.2023.2212015
A. Pandey, A. Upadhyay, K. Shukla
Abstract This article presents the low-velocity impact response of the multi-core aluminum honeycomb sandwich panel with composite face sheets using LS-DYNA-based finite element simulation. The effect of geometric parameters like cell size, cell height, cell thickness, and facesheet thickness, on structural response, is explored. The interaction effect of these geometric parameters, effect of number of layers/cores and characteristic force-time and energy-time curves for multilayer composite sandwich panels are also studied. Finally, these geometric parameters are optimized for better crashworthiness designs, followed by crashworthiness design recommendations.
{"title":"Multi-objective optimization of multi-core composite aluminum honeycomb sandwich panels for improved crashworthiness","authors":"A. Pandey, A. Upadhyay, K. Shukla","doi":"10.1080/15502287.2023.2212015","DOIUrl":"https://doi.org/10.1080/15502287.2023.2212015","url":null,"abstract":"Abstract This article presents the low-velocity impact response of the multi-core aluminum honeycomb sandwich panel with composite face sheets using LS-DYNA-based finite element simulation. The effect of geometric parameters like cell size, cell height, cell thickness, and facesheet thickness, on structural response, is explored. The interaction effect of these geometric parameters, effect of number of layers/cores and characteristic force-time and energy-time curves for multilayer composite sandwich panels are also studied. Finally, these geometric parameters are optimized for better crashworthiness designs, followed by crashworthiness design recommendations.","PeriodicalId":315058,"journal":{"name":"International Journal for Computational Methods in Engineering Science and Mechanics","volume":"145 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-05-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122948914","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-04-12DOI: 10.1080/15502287.2023.2197264
C. R. A. Silva Junior, Roberto M. F. Squarcio
Abstract This paper proposes to apply the Neumann – Monte Carlo method to obtain the estimates of the statistical moments of the solution for stochastic bending problem of Levinson-Bickford beams, with uncertainty in beam stiffness. The approximate solutions represent the stochastic displacement processes. For uncertainty modeling, parameterized stochastic processes will be used. The methodology proposed in this work differs from the usual one, as it is developed from theoretical results of existence and uniqueness of the realizations. The consistency of the approximate solutions will be based on studies on the existence and uniqueness of the theoretical solutions to this problem. In addition, error estimates are presented for the statistical moments of the beam response. The uncertainty will be quantified by estimating the statistical moments of the stochastic transverse displacement processes. The Monte Carlo simulation method is used to evaluate the performance of the proposed methodology.
摘要本文提出用Neumann - Monte Carlo方法求出具有梁刚度不确定性的Levinson-Bickford梁随机弯曲问题解的统计矩估计。近似解表示随机位移过程。对于不确定性建模，将使用参数化随机过程。在这项工作中提出的方法不同于通常的方法，因为它是从现实存在和独特性的理论结果发展而来的。近似解的一致性将基于对该问题理论解的存在唯一性的研究。此外，给出了梁响应统计矩的误差估计。不确定性将通过估计随机横向位移过程的统计矩来量化。采用蒙特卡罗仿真方法对所提方法的性能进行了评价。
{"title":"New error estimators, based on the Neumann-Monte Carlo methodology for quantification of the uncertainty of the problem of stochastic bending of Levinson-Bickford beam","authors":"C. R. A. Silva Junior, Roberto M. F. Squarcio","doi":"10.1080/15502287.2023.2197264","DOIUrl":"https://doi.org/10.1080/15502287.2023.2197264","url":null,"abstract":"Abstract This paper proposes to apply the Neumann – Monte Carlo method to obtain the estimates of the statistical moments of the solution for stochastic bending problem of Levinson-Bickford beams, with uncertainty in beam stiffness. The approximate solutions represent the stochastic displacement processes. For uncertainty modeling, parameterized stochastic processes will be used. The methodology proposed in this work differs from the usual one, as it is developed from theoretical results of existence and uniqueness of the realizations. The consistency of the approximate solutions will be based on studies on the existence and uniqueness of the theoretical solutions to this problem. In addition, error estimates are presented for the statistical moments of the beam response. The uncertainty will be quantified by estimating the statistical moments of the stochastic transverse displacement processes. The Monte Carlo simulation method is used to evaluate the performance of the proposed methodology.","PeriodicalId":315058,"journal":{"name":"International Journal for Computational Methods in Engineering Science and Mechanics","volume":"5 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-04-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130638661","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-03-31DOI: 10.1080/15502287.2023.2186971
Kedar S. Pakhare, R. Shimpi, P. Guruprasad
Abstract The van der Waals (vdW) force, along with the electrostatic force and the first-order fringing field effect, act on the electrostatically actuated nano-cantilever (EANC) when the gap between the deformable electrode and the stationary electrode is less than 20 nanometres. Because of the vdW force, the EANC can undergo a pull-in phenomenon even without the electrostatic force when the nano-cantilever length exceeds its detachment length. The vdW force also results in a significant reduction in static pull-in instability parameters of the slender EANC compared to corresponding parameters obtained when this force is absent. This paper aims to augment the stable static travel range (i.e., the pull-in displacement) of the aforementioned EANC having a length close to its detachment length by varying the beam width. The beam width is assumed to vary in linear and parabolic manners and is controlled using a width variation parameter in each case. The governing equation of the Bernoulli-Euler beam theory and the Galerkin’s technique are utilised to obtain the weighted residual statement (GWRS). The GWRS is utilised to obtain static pull-in instability parameters of referential prismatic and variable-width EANCs. Pull-in instability parameters of variable-width EANCs, for various values of width variation parameters and the initial gap between electrodes, have been obtained. The aforementioned results have been validated with corresponding results obtained by three-dimensional finite element simulations performed using COMSOL Multiphysics®. Compared to the referential prismatic EANC, a significant augmentation in the pull-in displacement of the variable-width EANC has been obtained.
{"title":"Augmentation of the stable static travel range of electrostatically actuated slender nano-cantilevers by accounting for the influence of the van der Waals force","authors":"Kedar S. Pakhare, R. Shimpi, P. Guruprasad","doi":"10.1080/15502287.2023.2186971","DOIUrl":"https://doi.org/10.1080/15502287.2023.2186971","url":null,"abstract":"Abstract The van der Waals (vdW) force, along with the electrostatic force and the first-order fringing field effect, act on the electrostatically actuated nano-cantilever (EANC) when the gap between the deformable electrode and the stationary electrode is less than 20 nanometres. Because of the vdW force, the EANC can undergo a pull-in phenomenon even without the electrostatic force when the nano-cantilever length exceeds its detachment length. The vdW force also results in a significant reduction in static pull-in instability parameters of the slender EANC compared to corresponding parameters obtained when this force is absent. This paper aims to augment the stable static travel range (i.e., the pull-in displacement) of the aforementioned EANC having a length close to its detachment length by varying the beam width. The beam width is assumed to vary in linear and parabolic manners and is controlled using a width variation parameter in each case. The governing equation of the Bernoulli-Euler beam theory and the Galerkin’s technique are utilised to obtain the weighted residual statement (GWRS). The GWRS is utilised to obtain static pull-in instability parameters of referential prismatic and variable-width EANCs. Pull-in instability parameters of variable-width EANCs, for various values of width variation parameters and the initial gap between electrodes, have been obtained. The aforementioned results have been validated with corresponding results obtained by three-dimensional finite element simulations performed using COMSOL Multiphysics®. Compared to the referential prismatic EANC, a significant augmentation in the pull-in displacement of the variable-width EANC has been obtained.","PeriodicalId":315058,"journal":{"name":"International Journal for Computational Methods in Engineering Science and Mechanics","volume":"40 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-03-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123523570","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-03-23DOI: 10.1080/15502287.2023.2186965
M. Ferdows, Nayema Islam Nima, G. C. Shit
Abstract The goal of this research is to look at two dimensional steady free forced convective flows through a horizontal surface surrounded by a permeable medium with exponential decaying heat generation and chemical reaction. For describing non–isothermal phenomena power law exponent has been considered in boundary conditions. By imposing appropriate transformations, the nonlinear partial differential equations driving the flow, temperature, concentration, and microbe fields are reduced to a system of ordinary differential equations and numerically solved by MATLAB 14.0. Excellent compatibility has been discovered between our optimized results and the already-published literature when compared for validation. The velocity, temperature, concentration, and microbe profiles are reduced by the power law exponent, which shows fluctuation in wall temperature and concentrations. Lewis parameter Le has a significant impact on concentration. The bioconvection peclet number Pe and the Lewis parameter Lb both significantly affect the profile of microorganisms. The influence of internal heat generation and chemical reaction can cause heat and mass transfer rates to increase, but slow down the transfer rate of motile microorganisms. For regions of forced convection, all flow profiles and flow transfer rates increase whereas they drop for regions of pure mixed convection.
{"title":"Chemical reactions and heat generation influence on mixed convection flow with gyrotactic microorganisms over a non-isothermal horizontal surface","authors":"M. Ferdows, Nayema Islam Nima, G. C. Shit","doi":"10.1080/15502287.2023.2186965","DOIUrl":"https://doi.org/10.1080/15502287.2023.2186965","url":null,"abstract":"Abstract The goal of this research is to look at two dimensional steady free forced convective flows through a horizontal surface surrounded by a permeable medium with exponential decaying heat generation and chemical reaction. For describing non–isothermal phenomena power law exponent has been considered in boundary conditions. By imposing appropriate transformations, the nonlinear partial differential equations driving the flow, temperature, concentration, and microbe fields are reduced to a system of ordinary differential equations and numerically solved by MATLAB 14.0. Excellent compatibility has been discovered between our optimized results and the already-published literature when compared for validation. The velocity, temperature, concentration, and microbe profiles are reduced by the power law exponent, which shows fluctuation in wall temperature and concentrations. Lewis parameter Le has a significant impact on concentration. The bioconvection peclet number Pe and the Lewis parameter Lb both significantly affect the profile of microorganisms. The influence of internal heat generation and chemical reaction can cause heat and mass transfer rates to increase, but slow down the transfer rate of motile microorganisms. For regions of forced convection, all flow profiles and flow transfer rates increase whereas they drop for regions of pure mixed convection.","PeriodicalId":315058,"journal":{"name":"International Journal for Computational Methods in Engineering Science and Mechanics","volume":"93 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-03-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131801971","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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