Pub Date : 2022-02-22DOI: 10.13052/ejcm2642-2085.3111
J. Alam, M. G. Murtaza, E. Tzirtzilakis, M. Ferdows
In this paper, the laminar, incompressible and viscous flow of a biomagnetic fluid containing Fe33O44 magnetic particles, through a two dimensional stretched cylinder is numerically studied in the presence of a magnetic dipole. The extended formulation of Biomagnetic Fluid Dynamics (BFD) which involves the principles of MagnetoHydroDynamic (MHD) and FerroHydroDynamic (FHD) is adopted. The pressure terms are also taken consideration. The physical problem which is described by a coupled system of partial differential equations along with corresponding boundary conditions is converted to a coupled system of nonlinear ordinary differential equations subject to analogous boundary conditions utilizing similarity approach. The numerical solution is obtained by using an efficient technique which is based on a common finite difference method with central differencing, a tridigonal matrix manipulation and an iterative procedure. For verification proposes a comparison with previously published results is also made. The numerous results concerning the axial velocity, temperature, pressure, skin friction coefficient, rate of heat transfer and wall pressure parameter are presented for various values of the parameters. The axial velocity is decreased as the ferromagnetic number increases, temperature is enhanced with increasing values of the magnetic parameter.
{"title":"Magnetohydrodynamic and Ferrohydrodynamic Interactions on the Biomagnetic Flow and Heat Transfer Containing Magnetic Particles Along a Stretched Cylinder","authors":"J. Alam, M. G. Murtaza, E. Tzirtzilakis, M. Ferdows","doi":"10.13052/ejcm2642-2085.3111","DOIUrl":"https://doi.org/10.13052/ejcm2642-2085.3111","url":null,"abstract":"In this paper, the laminar, incompressible and viscous flow of a biomagnetic fluid containing Fe33O44 magnetic particles, through a two dimensional stretched cylinder is numerically studied in the presence of a magnetic dipole. The extended formulation of Biomagnetic Fluid Dynamics (BFD) which involves the principles of MagnetoHydroDynamic (MHD) and FerroHydroDynamic (FHD) is adopted. The pressure terms are also taken consideration. The physical problem which is described by a coupled system of partial differential equations along with corresponding boundary conditions is converted to a coupled system of nonlinear ordinary differential equations subject to analogous boundary conditions utilizing similarity approach. The numerical solution is obtained by using an efficient technique which is based on a common finite difference method with central differencing, a tridigonal matrix manipulation and an iterative procedure. For verification proposes a comparison with previously published results is also made. The numerous results concerning the axial velocity, temperature, pressure, skin friction coefficient, rate of heat transfer and wall pressure parameter are presented for various values of the parameters. The axial velocity is decreased as the ferromagnetic number increases, temperature is enhanced with increasing values of the magnetic parameter.","PeriodicalId":45463,"journal":{"name":"European Journal of Computational Mechanics","volume":" ","pages":""},"PeriodicalIF":1.2,"publicationDate":"2022-02-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49457503","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 : 2022-01-22DOI: 10.13052/ejcm2642-2085.30468
Yuhang Huang, Haibo Jiang
In order to explore the characteristics of plastic zone and the mechanical properties of anchor structure during the construction of hydraulic tunnels with high ground temperature, the high-temperature section of the diversion tunnel of a hydropower station in Xinjiang was studied. Based on the temperature data and the axial force data of the bolt on-site, the Drucker-Prager constitutive model and the finite element method were adopted to simulate and analyze the temperature-stress coupled field and the initial anchoring support during the construction of the high ground temperature tunnels. The results showed that, after the excavation of the tunnel, a crescent-shaped plastic zone first appeared at the hance, then expanded to the spandrel and vault, and finally formed an irregular ring-shaped plastic zone around the tunnel. The higher the initial temperature of surrounding rocks, the larger the plastic deformation and the range of the plastic zone. When the temperature exceeded 80∘∘C, the plastic zone was more likely to expand to the spandrel and vault; and meanwhile, when the bolt was closer to the hance, the neutral point was closer to the cavity wall. As the stress was released, the neutral point moved from close to the cavity wall to away from the cavity wall. Anchoring support can effectively limit the development of plastic zone in surrounding rocks under high ground temperature. After 10 days of anchoring support at 60∘∘C, 80∘∘C, and 100∘∘C, the range of the plastic zone decreased by 9%, 20%, 24%, respectively, and the maximum axial force of a single bolt was 19.4 kN, 20.1 kN, and 23.8 kN, respectively. The higher the temperature, the higher the strength of the bolt.
{"title":"Analysis of Characteristics of Plastic Zone and Mechanical Properties of Anchor Structure in Hydraulic Tunnels with High Ground Temperature","authors":"Yuhang Huang, Haibo Jiang","doi":"10.13052/ejcm2642-2085.30468","DOIUrl":"https://doi.org/10.13052/ejcm2642-2085.30468","url":null,"abstract":"In order to explore the characteristics of plastic zone and the mechanical properties of anchor structure during the construction of hydraulic tunnels with high ground temperature, the high-temperature section of the diversion tunnel of a hydropower station in Xinjiang was studied. Based on the temperature data and the axial force data of the bolt on-site, the Drucker-Prager constitutive model and the finite element method were adopted to simulate and analyze the temperature-stress coupled field and the initial anchoring support during the construction of the high ground temperature tunnels. The results showed that, after the excavation of the tunnel, a crescent-shaped plastic zone first appeared at the hance, then expanded to the spandrel and vault, and finally formed an irregular ring-shaped plastic zone around the tunnel. The higher the initial temperature of surrounding rocks, the larger the plastic deformation and the range of the plastic zone. When the temperature exceeded 80∘∘C, the plastic zone was more likely to expand to the spandrel and vault; and meanwhile, when the bolt was closer to the hance, the neutral point was closer to the cavity wall. As the stress was released, the neutral point moved from close to the cavity wall to away from the cavity wall. Anchoring support can effectively limit the development of plastic zone in surrounding rocks under high ground temperature. After 10 days of anchoring support at 60∘∘C, 80∘∘C, and 100∘∘C, the range of the plastic zone decreased by 9%, 20%, 24%, respectively, and the maximum axial force of a single bolt was 19.4 kN, 20.1 kN, and 23.8 kN, respectively. The higher the temperature, the higher the strength of the bolt.","PeriodicalId":45463,"journal":{"name":"European Journal of Computational Mechanics","volume":" ","pages":""},"PeriodicalIF":1.2,"publicationDate":"2022-01-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42231319","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 : 2022-01-22DOI: 10.13052/ejcm2642-2085.30469
Vijay Panchore
The rotating Rayleigh beam problem is solved with meshfree method where the radial basis functions are explored. Numbers of basis functions have been used for meshfree methods which also include radial basis function. In this paper, the Gaussian radial basis function and multiquadrics radial basis functions are combined to get the new basis function which provides accuracy for higher natural frequencies. The radial basis functions satisfy the Kronecker delta property and it is easy to apply the essential boundary conditions. The Galerkin method is used for weak formulation. The matrices have been derived. The results are obtained for Gaussian radial basis function and new basis function. The results show more accurate values for fourth and fifth natural frequency with new basis function where only six nodes are used within the subdomain of trial and test function. The results are also obtained with conventional finite element method where forty, two node elements are considered. Also, the results are obtained for rotating Euler-Bernoulli beam to observe the difference in results with rotating Rayleigh beam.
{"title":"Meshfree Galerkin Method for a Rotating Non-Uniform Rayleigh Beam with Refinement of Radial Basis Functions","authors":"Vijay Panchore","doi":"10.13052/ejcm2642-2085.30469","DOIUrl":"https://doi.org/10.13052/ejcm2642-2085.30469","url":null,"abstract":"The rotating Rayleigh beam problem is solved with meshfree method where the radial basis functions are explored. Numbers of basis functions have been used for meshfree methods which also include radial basis function. In this paper, the Gaussian radial basis function and multiquadrics radial basis functions are combined to get the new basis function which provides accuracy for higher natural frequencies. The radial basis functions satisfy the Kronecker delta property and it is easy to apply the essential boundary conditions. The Galerkin method is used for weak formulation. The matrices have been derived. The results are obtained for Gaussian radial basis function and new basis function. The results show more accurate values for fourth and fifth natural frequency with new basis function where only six nodes are used within the subdomain of trial and test function. The results are also obtained with conventional finite element method where forty, two node elements are considered. Also, the results are obtained for rotating Euler-Bernoulli beam to observe the difference in results with rotating Rayleigh beam.","PeriodicalId":45463,"journal":{"name":"European Journal of Computational Mechanics","volume":" ","pages":""},"PeriodicalIF":1.2,"publicationDate":"2022-01-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46195088","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 : 2022-01-22DOI: 10.13052/ejcm2642-2085.304610
Mohammad Mehdi Zamani Asl, Zahra Dastyar
An axisymmetric numerical model is conducted to study the droplet impingement into a liquid film and crown formation. Through numerical modeling and experimental validation, the effect of different parameters such as surface tension, Weber number, and film thickness on crown evolution is investigated. Surfactant is added to water, aiming reduction of the surface tension in the surfactant-water mix. It was shown that the crown rim diameter increases with Weber in both water and surfactant-water mixture cases. Likewise, crown rim diameter increases with the film thickness in both different cases of fluids. Additionally, results revealed that surface tension does not affect the crown rim diameter. Nevertheless, crown height increases as surface tension decreases. At low values of surface tension, secondary droplets and the de-wetting region appear. These outcomes can be attributed to the domination of kinetic energy of crown rims in cases with low surface tensions.
{"title":"Droplet Impingement into a Liquid Film; Numerical Study of Surface Tension Effect on the Crown Formation","authors":"Mohammad Mehdi Zamani Asl, Zahra Dastyar","doi":"10.13052/ejcm2642-2085.304610","DOIUrl":"https://doi.org/10.13052/ejcm2642-2085.304610","url":null,"abstract":"An axisymmetric numerical model is conducted to study the droplet impingement into a liquid film and crown formation. Through numerical modeling and experimental validation, the effect of different parameters such as surface tension, Weber number, and film thickness on crown evolution is investigated. Surfactant is added to water, aiming reduction of the surface tension in the surfactant-water mix. It was shown that the crown rim diameter increases with Weber in both water and surfactant-water mixture cases. Likewise, crown rim diameter increases with the film thickness in both different cases of fluids.\u0000Additionally, results revealed that surface tension does not affect the crown rim diameter. Nevertheless, crown height increases as surface tension decreases. At low values of surface tension, secondary droplets and the de-wetting region appear. These outcomes can be attributed to the domination of kinetic energy of crown rims in cases with low surface tensions.","PeriodicalId":45463,"journal":{"name":"European Journal of Computational Mechanics","volume":" ","pages":""},"PeriodicalIF":1.2,"publicationDate":"2022-01-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44875689","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 : 2022-01-22DOI: 10.13052/ejcm2642-2085.30467
Zhicheng Wang, Jie Zhao, Md Rayhan Tanvir, Jiexian Mao
To further improvement of the aerodynamic performance simulation model accuracy of Vertical Axis Wind Turbine (VAWT), based on the traditional double multi-flow tube theoretical model, the aerodynamic parameters of the airfoil before and after stall are modified by the Lanchester method. Prand model is used to modify the aspect ratio of the airfoil under the condition of the small angle of attack before stall. Viterna Corrigan model is used to modify the aspect ratio, lift and drag coefficients of the airfoil under the stall. And a relaxation factor is introduced to correct the induction factor, also to improve the iterative non-convergence of the simulation under the condition of large tip speed ratio. The simulation results match the experimental data very well. Based on this new aerodynamic performance analysis method, the influence of blade tip speed ratio, blade number, blade chord length, rotor radius, and incoming wind speed on power coefficient and tangential force coefficient is studied, which can provide a reference for the design of aerodynamic performance parameters of the wind turbine.
{"title":"Analysis of Aerodynamic Characteristics of Vertical Axis Wind Turbine (VAWT) Based on Modified Double Multiple Stream Tube Model","authors":"Zhicheng Wang, Jie Zhao, Md Rayhan Tanvir, Jiexian Mao","doi":"10.13052/ejcm2642-2085.30467","DOIUrl":"https://doi.org/10.13052/ejcm2642-2085.30467","url":null,"abstract":"To further improvement of the aerodynamic performance simulation model accuracy of Vertical Axis Wind Turbine (VAWT), based on the traditional double multi-flow tube theoretical model, the aerodynamic parameters of the airfoil before and after stall are modified by the Lanchester method. Prand model is used to modify the aspect ratio of the airfoil under the condition of the small angle of attack before stall. Viterna Corrigan model is used to modify the aspect ratio, lift and drag coefficients of the airfoil under the stall. And a relaxation factor is introduced to correct the induction factor, also to improve the iterative non-convergence of the simulation under the condition of large tip speed ratio. The simulation results match the experimental data very well. Based on this new aerodynamic performance analysis method, the influence of blade tip speed ratio, blade number, blade chord length, rotor radius, and incoming wind speed on power coefficient and tangential force coefficient is studied, which can provide a reference for the design of aerodynamic performance parameters of the wind turbine.","PeriodicalId":45463,"journal":{"name":"European Journal of Computational Mechanics","volume":"1 1","pages":""},"PeriodicalIF":1.2,"publicationDate":"2022-01-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42032017","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 : 2022-01-01Epub Date: 2022-09-19DOI: 10.3389/fruro.2022.916259
Austin L Chien, Kevin J Chua, Sai Krishnaraya Doppalapudi, Saum Ghodoussipour
Upper tract urothelial carcinoma (UTUC) has traditionally been managed with radical nephroureterectomy, and while this approach remains the gold standard for high-risk disease, endoscopic, kidney-sparing management has increasingly been adopted for low-risk disease as it preserves kidney function without compromising oncologic outcomes. Ureteroscopy and percutaneous renal access not only provide diagnoses by tumor visualization and biopsy, but also enable treatment with electrocautery or laser ablation. Several modalities exist for laser ablative treatments including thulium:YAG, neodymium:YAG, holmium:YAG, and combinations of the preceding. Furthermore, due to high recurrence rates after endoscopic management, adjuvant intracavitary instillation of various agents such as mitomycin C and bacillus Calmette-Guerin have been used given benefits seen in non-muscle invasive urothelial bladder cancer. Other formulations also being studied include gemcitabine, anthracyclines, and immunotherapies. More recently, Jelmyto, a mitomycin reverse thermal gel, has been developed to allow for adequate drug delivery time and potency since urine flow could otherwise dilute and washout topical therapy. In this article, the authors review techniques, indications, best practices, and areas of current investigation in endoscopic management and adjuvant topical therapy for UTUC.
上尿路尿路上皮癌（UTUC）传统上采用根治性肾切除术进行治疗，虽然这种方法仍是治疗高风险疾病的金标准，但越来越多的低风险疾病采用内窥镜下的保肾治疗，因为这种方法既能保留肾功能，又不影响肿瘤治疗效果。输尿管镜检查和经皮肾穿刺不仅能通过肿瘤显像和活检进行诊断，还能通过电烧或激光消融进行治疗。目前有多种激光消融治疗方法，包括铥：YAG、钕：YAG、钬：YAG 以及上述几种方法的组合。此外，由于内镜治疗后的复发率较高，已经使用了丝裂霉素 C 和卡介苗杆菌等多种药物进行腔内辅助灌注，这对非肌层浸润性尿路膀胱癌大有裨益。其他正在研究的制剂包括吉西他滨、蒽环类和免疫疗法。最近开发的 Jelmyto 是一种丝裂霉素反向热凝胶，可提供足够的给药时间和药效，否则尿流会稀释和冲淡局部治疗。在本文中，作者回顾了UTUC内窥镜管理和局部辅助治疗的技术、适应症、最佳实践和当前研究领域。
{"title":"The role of endoscopic management and adjuvant topical therapy for upper tract urothelial cancer.","authors":"Austin L Chien, Kevin J Chua, Sai Krishnaraya Doppalapudi, Saum Ghodoussipour","doi":"10.3389/fruro.2022.916259","DOIUrl":"10.3389/fruro.2022.916259","url":null,"abstract":"<p><p>Upper tract urothelial carcinoma (UTUC) has traditionally been managed with radical nephroureterectomy, and while this approach remains the gold standard for high-risk disease, endoscopic, kidney-sparing management has increasingly been adopted for low-risk disease as it preserves kidney function without compromising oncologic outcomes. Ureteroscopy and percutaneous renal access not only provide diagnoses by tumor visualization and biopsy, but also enable treatment with electrocautery or laser ablation. Several modalities exist for laser ablative treatments including thulium:YAG, neodymium:YAG, holmium:YAG, and combinations of the preceding. Furthermore, due to high recurrence rates after endoscopic management, adjuvant intracavitary instillation of various agents such as mitomycin C and bacillus Calmette-Guerin have been used given benefits seen in non-muscle invasive urothelial bladder cancer. Other formulations also being studied include gemcitabine, anthracyclines, and immunotherapies. More recently, Jelmyto, a mitomycin reverse thermal gel, has been developed to allow for adequate drug delivery time and potency since urine flow could otherwise dilute and washout topical therapy. In this article, the authors review techniques, indications, best practices, and areas of current investigation in endoscopic management and adjuvant topical therapy for UTUC.</p>","PeriodicalId":45463,"journal":{"name":"European Journal of Computational Mechanics","volume":"20 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11160966/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91361201","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-12-30DOI: 10.13052/ejcm2642-2085.30466
B. J. Akinbo, B. Olajuwon
Heat generation effect in a steady two-dimensional magnetohydrodynamics (MHD) flow over a moving vertical plate with a medium porosity has been studied. By similarity transformation variables, the coupled non-linear ordinary differential equations describing the model are obtained. The resulting equation is then solved, using Galerkin Weighted Residual Method (GWRM), where the effect of heat generation, Magnetic Parameter as well as other physical parameters encountered were examined and discussed. Some of the major findings were that increase in heat generation and convective heat parameter enhances the plate surface temperature as well as temperature field which allows the thermal effect to penetrate deeper into the quiescent fluid.
{"title":"Effects of Heat Generation/Absorption on Magnetohydrodynamics Flow Over a Vertical Plate with Convective Boundary Condition","authors":"B. J. Akinbo, B. Olajuwon","doi":"10.13052/ejcm2642-2085.30466","DOIUrl":"https://doi.org/10.13052/ejcm2642-2085.30466","url":null,"abstract":"Heat generation effect in a steady two-dimensional magnetohydrodynamics (MHD) flow over a moving vertical plate with a medium porosity has been studied. By similarity transformation variables, the coupled non-linear ordinary differential equations describing the model are obtained. The resulting equation is then solved, using Galerkin Weighted Residual Method (GWRM), where the effect of heat generation, Magnetic Parameter as well as other physical parameters encountered were examined and discussed. Some of the major findings were that increase in heat generation and convective heat parameter enhances the plate surface temperature as well as temperature field which allows the thermal effect to penetrate deeper into the quiescent fluid.","PeriodicalId":45463,"journal":{"name":"European Journal of Computational Mechanics","volume":" ","pages":""},"PeriodicalIF":1.2,"publicationDate":"2021-12-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46074499","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 : 2021-12-08DOI: 10.13052/ejcm2642-2085.30464
A. Sharma, Aman Khurana, M. Joglekar
Among the available soft active materials, Dielectric elastomers (DEs) possess the capability of achieving the large actuation strain under the application of high electric field. The material behavior of such elastomers is affected significantly by the change in temperature. This paper reports a 3-D finite element framework based on the coupled nonlinear theory of thermo-electro-elasticity for investigating the thermal effects on the electromechanical performance of inhomogeneously deforming dielectric elastomer actuators (DEAs). The material behavior of the actuator is modeled using the neo-Hookean model of hyperelasticity with temperature dependent shear modulus. An in-house computational code is developed to implement the coupled finite element framework. Firstly, the accuracy of the developed FE code is verified by simulating the temperature effects on the actuation response and pull-in instability of the benchmark homogeneously deforming planar DE actuator. Further, the influence of temperature on the electromechanical responses of complex bi-layered bending actuator and buckling pump actuator involving inhomogeneous deformation is investigated. The numerical framework and the associated inferences can find their potential use in addressing the effect of temperature in the design of electro-active polymer based actuators.
{"title":"Finite Element Model for Investigating the Thermo-Electro-Mechanical Response of Inhomogeneously Deforming Dielectric Elastomer Actuators","authors":"A. Sharma, Aman Khurana, M. Joglekar","doi":"10.13052/ejcm2642-2085.30464","DOIUrl":"https://doi.org/10.13052/ejcm2642-2085.30464","url":null,"abstract":"Among the available soft active materials, Dielectric elastomers (DEs) possess the capability of achieving the large actuation strain under the application of high electric field. The material behavior of such elastomers is affected significantly by the change in temperature. This paper reports a 3-D finite element framework based on the coupled nonlinear theory of thermo-electro-elasticity for investigating the thermal effects on the electromechanical performance of inhomogeneously deforming dielectric elastomer actuators (DEAs). The material behavior of the actuator is modeled using the neo-Hookean model of hyperelasticity with temperature dependent shear modulus. An in-house computational code is developed to implement the coupled finite element framework. Firstly, the accuracy of the developed FE code is verified by simulating the temperature effects on the actuation response and pull-in instability of the benchmark homogeneously deforming planar DE actuator. Further, the influence of temperature on the electromechanical responses of complex bi-layered bending actuator and buckling pump actuator involving inhomogeneous deformation is investigated. The numerical framework and the associated inferences can find their potential use in addressing the effect of temperature in the design of electro-active polymer based actuators.","PeriodicalId":45463,"journal":{"name":"European Journal of Computational Mechanics","volume":" ","pages":""},"PeriodicalIF":1.2,"publicationDate":"2021-12-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47378317","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 : 2021-12-08DOI: 10.13052/ejcm2642-2085.30465
N. Rajkamal, S. Vedantam
We present a dissipative particle dynamics (DPD) study of the deformation of capsules in microchannels. The strain in the membrane during this deformation causes the formation of temporary pores, which is termed mechanoporation. Mechanoporation is being considered as a means by which intracellular delivery of a broad range of cargo can be facilitated. In this work, we examine the strain distribution on the capsule membrane during transport of the capsule in converging-diverging microchannels of different constriction widths. The pore density is correlated to the strain in the membrane. We find that the highest strains and, consequently, the highest pore densities occur at intermediate channel widths. This occurs due to a competition of the bending of the membrane and fluid shear stresses in the flow.
{"title":"Dissipative Particle Dynamics Study of Strain Distribution in Capsules Deformed by Microfluidic Constrictions","authors":"N. Rajkamal, S. Vedantam","doi":"10.13052/ejcm2642-2085.30465","DOIUrl":"https://doi.org/10.13052/ejcm2642-2085.30465","url":null,"abstract":"We present a dissipative particle dynamics (DPD) study of the deformation of capsules in microchannels. The strain in the membrane during this deformation causes the formation of temporary pores, which is termed mechanoporation. Mechanoporation is being considered as a means by which intracellular delivery of a broad range of cargo can be facilitated. In this work, we examine the strain distribution on the capsule membrane during transport of the capsule in converging-diverging microchannels of different constriction widths. The pore density is correlated to the strain in the membrane. We find that the highest strains and, consequently, the highest pore densities occur at intermediate channel widths. This occurs due to a competition of the bending of the membrane and fluid shear stresses in the flow.","PeriodicalId":45463,"journal":{"name":"European Journal of Computational Mechanics","volume":" ","pages":""},"PeriodicalIF":1.2,"publicationDate":"2021-12-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48472067","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 : 2021-11-27DOI: 10.13052/ejcm2642-2085.30463
A. Belhocine, N. Stojanović, O. Abdullah
In this paper, steady laminar boundary layer flow of a Newtonian fluid over a flat plate in a uniform free stream was investigated numerically when the surface plate is heated by forced convection from the hot fluid. This flow is a good model of many situations involving flow over fins that are relatively widely spaced. All the solutions given here were with constant fluid properties and negligible viscous dissipation for two-dimensional, steady, incompressible laminar flow with zero pressure gradient. The similarity solution has shown its efficiency here to transform the governing equations of the thermal boundary layer into a nonlinear, third-order ordinary differential equation and solved numerically by using 4th-order Runge-Kutta method which in turn was programmed in FORTRAN language. The dimensionless temperature, velocity, and all boundary layer functions profiles were obtained and plotted in figures for different parameters entering into the problem. Several results of best approximations and expressions of important correlations relating to heat transfer rates were drawn in this study of which Prandtl’s number to the plate for physical interest was also discussed across the tables. The same case of solution procedure was made for a plane plate subjected to other thermal boundary conditions in a laminar flow. Finally, for the validation of the treated numerical model, the results obtained are in good agreement with those of the specialized literature, and comparison with available results in certain cases is excellent.
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