Solid Cylinder Research Articles

ANALYTICAL AND NUMERICAL ANALYSIS OF SOLID CYLINDER MADE OF RADIALLY NONUNIFORM MATERIAL UNDER EXTENSION

Functionally graded materials are inhomogeneous composite materials, composed of two or more constituents selected to achieve desirable properties for specific applications. In this work, a solid cylindrical tube made of inhomogeneous composite materials under tensile action was analyzed within the context of three-dimensional elasticity theory. An analytical solution was obtained for computing the displacement and stress fields. It has been assumed that the elastic stiffness is varying through the functionally graded material according to radial variation laws: linear, power, and exponential laws, while Poisson's ratio is considered as constant. In order to check the relevance of the analytical solution, a finite element model of the cylindrical tube was constructed, taking into account variations in Young's modulus. Very good agreement has been found between the numerical results and the predictions of the analytical solution, which confirms the accuracy of our model. Numerous curves were plotted by adjusting the inhomogeneity parameter and the elongation value, revealing a significant effect. Thus, the inhomogeneity in material properties can be exploited to optimize stress distribution. Indeed, by tailoring the material properties to match the stress distribution in a specific load scenario, stress concentrations can be minimized in high-stress areas.

MODELING OF VIBRATIONS OF A STACKED PIEZO ELEMENT MADE OF POROUS PIEZOCERAMICS

The work is devoted to a numerical study of the effectiveness of using porous piezoceramics in a stacked piezoelectric element, which can be used as a power drive element, a piezoelectric generator, or an ultrasonic emitter. The use of porous piezoceramics in stacked piezoelements has not received enough attention in the literature. The use of porous piezoceramics in stacked piezo elements has not received enough attention in the literature. The paper considers a stacked piezo element consisting of eight solid cylinders counter-polarized in the axial direction. The material of the cylinders is PZT-4 piezoceramic, the porosity of which varies from 0% to 80%. The problem of axial steady-state oscillations in the vicinity of the first resonance frequency and below it is solved. The lower end of the cylinder is fixed along the normal, excitation of oscillations is carried out by mechanical action under uniformly distributed pressure at the upper face or by the action of electric potential difference at the electrodes. The problems are solved in the framework of linear axisymmetric theory of electroelasticity. With mechanical action, the output characteristic of the device is the electrical potential of the free electrodes; with electrical action, it is the amplitude of the axial vibrations of the upper end or the reaction force if it is fixed. The finite element method implemented in the ACELAN package is used as the solution method. As a result of the numerical solution, the dependence of the percentage of porosity on the output characteristics of the piezo element is investigated: the frequencies of resonance and antiresonance, the electromechanical coupling coefficient, the output potential under mechanical loading, the amplitude of oscillations of the free upper end and the coupling reaction at its fixing when the oscillations are excited by the potential difference and the energy of the elastic element attached to this end. The analysis of the dependence of these characteristics allows us to conclude that it is reasonable to use such an element with porous ceramics as a piezoelectric generator and transmitter. It is noted that the choice of the percentage of porosity depends directly on the intensity of loads and the strength of porous piezoceramics.

Estimating the interfacial permeability for flow into a poroelastic medium.

Boundary conditions between a porous solid and a fluid has been a long-standing problem in modeling porous media. For deformable poroelastic materials such as hydrogels, the question is further complicated by the elastic stress from the solid network. Recently, an interfacial permeability condition has been developed from the principle of positive energy dissipation on the hydrogel-fluid interface. Although this boundary condition has been used in flow computations and yielded reasonable predictions, it contains an interfacial permeability η as a phenomenological parameter. In this work, we use pore-scale models of flow into a periodic array of solid cylinders or parallel holes to determine η as a function of the pore size and porosity. This provides a means to evaluate the interfacial permeability for a wide range of poroelastic materials, including hydrogels, foams and biological tissues, to enable realistic flow simulations.

The shape of an axisymmetric meniscus in a static liquid pool: effective implementation of the Euler transformation

Abstract We examine the classical problem of the height of a static liquid interface that forms on the outside of a solid vertical cylinder in an unbounded stagnant pool exposed to air. Gravitational and surface tension forces compete to affect the interface shape as characterized by the Bond number. Here, we provide a convergent power series solution for interface shapes that rise above or fall below the horizontal pool as a function of contact angle and Bond number. We find that the power series solution expressed in terms of the radial distance from the wall is divergent, and thus rewrite the divergent series as a new power series expressed as powers of an Euler transformed variable; this series is modified to match the large distance asymptotic behaviour of the meniscus. The Euler transformation maps non-physical singularities to locations that do not restrict series convergence in the physical domain, while the asymptotic modification increases the rate of convergence of the series overall. We demonstrate that when the divergent series coefficients are used to implement the Euler transformation, finite precision errors are incurred, even for a relatively small number of terms. To avoid such errors, the independent variable in the governing differential equation is changed to that of the Euler transform, and the power series is developed directly without using the divergent series. The resulting power series solution is validated by comparison with a numerical solution of the interface shape and the small Bond number matched asymptotic solution for the height of the interface along the cylinder developed by Lo (1983, J. Fluid Mech., 132, p.65-78). The convergent power series expansion has the ability to exceed the accuracy of the matched asymptotic solution for any Bond number given enough terms, and the recursive nature of the solution makes it straightforward to implement.

OUTER CYLINDRICAL SPACES OF A HOLLOW CYLINDER OF FINITE LENGTH

Introduction. The solution of the Laplace equation by the method of separation of Fourier variables for cylindrical domains makes it possible to study electromechanical devices in 3D format.
 
 The purpose of the study is to obtain analytical expressions for magnetic potentials and inductions of external three-dimensional spaces of electromechanical devices in a cylindrical coordinate system.
 
 Materials and methods. The unknown constants in the expressions for the regions under consideration are found from the boundary conditions of the magnetic field at the common boundaries of the electromechanical device with its outer space: the scalar magnetic potentials and magnetic inductions are the same, the current sheets experience a jump. When obtaining analytical expressions, the methods of mathematical physics were used.
 
 Research results. To find the Fourier constants, the outer three-dimensional spaces of classical electromechanical devices (generators, motors) are considered, which in a cylindrical coordinate system are represented by both hollow and solid cylinders joining the active regions of the devices with their cylindrical or end surfaces. General expressions for magnetic potentials and inductions of external spaces are obtained based on the solution of the Laplace equation as the Sturm–Liouville problem by the Fourier method of separation of variables. The magnetic fields of the outer spaces of the original hollow cylinder are analyzed: an outer cylinder with an infinitely large radius; internal solid cylinder; end cylinders of finite length. These data make it possible to increase the required number of equations to find the required number of Fourier constants in the analytical calculation of electromechanical devices by the method of separation of variables.
 
 Findings. Analytical expressions for the boundary values of magnetic potentials and inductions of the external space adjacent to the active regions of electromechanical devices with air gaps of both radial and axial form are obtained.

Neutral inhomogeneity in circular cylinder subjected to prescribed boundary displacement

In this paper a single circular inhomogeneity embedded within a solid circular cylinder whose curved boundary surface is subjected to a given boundary displacement in axial direction is considered. The displacement neutrality of the coupled system of host body and inclusion is studied. The neutral inhomogeneity (inclusion) does not disturb the displacement, strain and stress fields in the host body. In this paper the deformation of the considered inhomogeneous cylinder is a linear antiplane shear deformation.

Moore–Gibson–Thompson Coupled Hygro-Photo-Thermoelastic Solid Cylinder with Hyperbolic Two Temperatures

Moore–Gibson–Thompson Coupled Hygro-Photo-Thermoelastic Solid Cylinder with Hyperbolic Two Temperatures

Novel bio-waste of Cinnamomum Verum leaves-derived carbon coin cylinder-like as sustainable electrode material for symmetrical supercapacitor

Carbon material sourced from bio-organic waste is a promising electrode material exploration for the development of sustainable supercapacitor devices. Interestingly, their relatively environmentally benign sources and unlimited availability are the right choices to be developed as energy conversion systems and energy storage applications. Here, a novel high-potential bio-waste has been studied as a carbon source for electrode materials for symmetrical supercapacitor applications. Biomass materials were selected from Cinnamomum Verum leaves waste which was given a series of measurable and systematically structured treatments. Carbon precursor was synthesized with a simple strategy through a one/two-step activation ratio in an integrated pyrolysis system. Their chemical impregnation focused on H3PO4, ZnCl2, and H3PO4+ZnCl2 solutions. The renewal of the study was also highlighted in the design of a solid coin-like carbon cylinder material without additive binder. The solid carbon material that has been obtained has been evaluated for all dimensions including mass, thickness, diameter, and volume. In addition, the density of the coins that have been generated through density calculations is also reviewed. The density of the coin’s carbon shows a value of 0.98 g cm−3 with an average standard deviation of 0.08. The electrochemical properties of carbon electrode materials were studied through cyclic voltammetry (CV) and galvanostatic charge-discharge (GCD) analysis. In the two-system configuration, the optimized electrode exhibits a specific capacitance of 162.83 F g−1 at 1 A g−1 and 101 F g−1 at 10 A g−1. Furthermore, their performance is relatively high at a coulombic efficiency of around 76.23% with a capability rate of 63.11%. Moreover, the resulting energy density is 17.18 Wh kg−1 at a maximum power density of 125 W kg−1. Therefore, this study offers a new strategy to obtain carbon solid coin-like from bio-organic sources of Cinnamon Verum leaves as a high-quality electrode material to improve the performance of symmetric energy storage devices.

Analysis of Multilayer Cylindrical Thermal Conduction With a Time-Varying Convective Boundary Condition

Abstract Heat transfer in a multilayer body plays a key role in design and optimization of several engineering systems. While the analysis of simple multilayer problems is quite straightforward, realistic scenarios such as time-dependent boundary conditions result in significant complications in analysis. This work presents thermal analysis of a one-dimensional heat-generating multilayer cylinder with time-varying convective heat transfer at the boundary. Such a scenario may occur in applications such as nuclear reactors, jet impingement cooling, turbine blade heat transfer, as well as casting and related manufacturing processes. Analysis is presented for both annular and solid cylinders. A derivation for the temperature distribution is carried out, using a shifting function to split the time-dependent boundary condition into two parts, followed by appropriate mathematical substitution. For particular special cases, the analytical results derived here are shown to reduce exactly to results from past work. Good agreement of the theoretical results with numerical simulations is also demonstrated. Thermal response to various realistic time-dependent boundary conditions is analyzed. This work contributes towards the design of realistic multilayer problems and may facilitate the optimization of engineering systems where multilayer thermal conduction plays a key role.

Passive elimination of flow-induced forces and vibrations of a circular cylinder using a slit

Here, passive flow control technique of incorporating a slit through a circular structure is utilized to dampen the flow-induced vibration (FIV). The study is segregated into two main sections, one where the effect of slit width ratio (S/D) and Reynolds number (Re) is investigated on the fixed stationary cylinder, and the other where the effect of slit size is explored on the behavior of the elastically mounted cylinder with varying reduced velocities (Ur) at Re = 100. The slit width ratio is varied from 0% (no slit) to 50% and Re from 100 to 300 for a stationary cylinder. For elastically mounted cylinder, the mass (m* = 5) and damping (ζ = 0.01) ratios and Re (100) are fixed, whereas Ur is varied from 0 to 10. The results are expressed as coefficient of lift and drag, Strouhal number, amplitude and frequency of vibration, force-displacement plots, and vorticity contours. They indicate that the presence of a slit reduces the lift and drag coefficients and suppresses the FIV. At Re = 100, the presence of 10% and 20% slit decreases the lift coefficient by 13.0% and 71.8%, respectively, as compared to the solid cylinder. Considering the maximum amplitude of vibration, a 10% slit resulted in a 5.7% amplitude drop, whilst a 20% slit resulted in a significant drop of 34.4% as compared to the solid cylinder. Further increasing the slit size from 20% to 30% completely vanished the vortex shedding and led to steady flow with zero lift and no vibration.

On Poro-hyperelastic Torsion

The paper examines the torsion of a solid cylinder composed of a fluid-saturated porous medium with a hyperelastic porous skeleton. The general formulation of the problem is followed with applications to special cases where the strain energy function for the skeletal behavior is described by either a neoHookean or an Ogden-type hyperelastic behavior. The analytical developments involve the numerical solution of the governing equations followed by a computational treatment of the problems using the ABAQUS™ finite element code. The time-dependent mechanics of the twisted cylinder is examined for the instantaneous short-term behavior as well as the long-term behavior when the excess fluid pressures generated during the application of a finite twist have dissipated.

High power pulse delivery over a short distance through an all-solid anti-resonant microstructured optical fiber at [formula omitted] wavelength

We propose an all-solid silica-based, large mode area (LMA) anti-resonant microstructured optical fiber through which optical pulses of high-power can be delivered at the near mid-infrared wavelength range. Anti-resonant guidance of light has been achieved in the silica-based microstructured geometry by embedding 15 high-index solid cylinders in a low-index background matrix that essentially creates a node-less negative curvature cladding region surrounding the low-index core. The fiber geometry has been optimized in such a way that a large mode area of ∼2000μm2 is achieved for the fundamental mode with a loss in the order of 0.04 dB/m at 2μm wavelength. Moreover, the higher-order modes are at least one order of magnitude lossy than the fundamental mode at the operating wavelength. The optimized fiber structure has exhibited that a pulse of peak power as high as 1 kW and width of 2.2 ps can be sustained without any alteration in shape and degradation of power when the pulse is delivered through the fundamental mode over the proposed fiber length of 25 m. Hence, this proposed unique silica-based all-solid anti-resonant fiber structure is suitable for short-distance delivery of high-power pulses at 2μm wavelength with effective single mode separation.

Hygro-photo-thermoelastic solid cylinder under moisture and thermal diffusivity with Moore-Gibson-Thompson theory

A new model for the simulation of moisture and thermal diffusivity in a semiconducting solid cylinder according to the Moore-Gibson-Thompson-Photo-Thermal (MGTPT) theory of thermoelasticity has recently been presented. The purpose of this study is to investigate the photo-thermoelasticity of an infinite semiconducting solid cylinder rotating with the boundary surface being subjected to a laser pulse with variable heat flux. For this purpose, the mathematical model is solved by using the Laplace transform technique in the transformed domain. The numerical inversion of the mathematical model yields all the physical parameters in the physical domain, such as displacement components, thermal stresses, and carrier densities. To clearly illustrate the effects of reference moisture, a graphic representation of all these parameters is generated by using the MATLAB software. The results of this study will be useful in further enhancing the behavior of semiconductors under these dynamic loading conditions and hence, improve their performance in various applications.Thus, the model provides an effective way to model the moisture and thermal diffusivities of the solid cylinder to better understand phenomena occurring in a broad range of semiconductor devices and more effectively design them.

Application of Collins’ upper bound theorem to upsetting processes

The standard formulation of the upper bound theorem is incompatible with the Coulomb friction law. However, this law is widely used in metal forming processes analysis. An alternative formulation based on non-kinematically admissible velocity fields can evaluate the load required to deform the material. The present paper adopts this formulation for evaluating the compression force in solid and hollow cylinder compression processes. The trial velocity fields are continuous. The field for the solid cylinder involves no parameter for minimization, and the field for the hollow cylinder involves one parameter. Parametric analyses of the solutions are provided. The compression forces found are compared to available results at small friction coefficients. The solution is also in agreement with physical expectations. In particular, the solution for the hollow cylinder compression predicts that the radial velocity is everywhere positive in the friction coefficient is small enough. For larger friction coefficients, the radius where the radial velocity vanishes propagates from the inner radius as the friction coefficient increases. The final result can be used in conjunction with standard procedures for evaluating the friction coefficient.

Wake characteristics of wall-mounted solid and foam-covered circular cylinders

The wake characteristics of wall-mounted finite submerged solid and foam-covered circular cylinders (height/diameter = 0.9) are explored using large-eddy simulation for a Reynolds number (based on the cylinder diameter) of 13 000, and the simulation results are validated using particle image velocimetry. The foam-covered cylinder consists of an inner cylinder wrapped with a highly porous open-cell foam and capped by circular plates at the top and bottom. Two recirculation regions are identified for both cylinders, based on time-averaged data, one downstream and another above the top surface of the cylinder. The presence of the foam induces changes in the characteristics of both recirculation regions. The foam covering also interrupts the formation of large periodic structures, the evidence of which can be seen in the temporal distribution and discrete Fourier analysis of the force coefficients and velocity fluctuations. The temporal lateral oscillations, represented by the coefficient of sway, are observed for the solid cylinder but are suppressed in the case of the foam-covered cylinder. Two dominating frequencies are consistently present for the solid cylinder, but no such frequencies can be identified for the foam-covered cylinder. Finally, spectral proper orthogonal decomposition modes are presented in order to further substantiate the findings.

Nonlinear mechanics of remodeling

In this paper, we present a large-deformation formulation of the mechanics of remodeling. Remodeling is anelasticity with an internal constraint—material evolutions that are mass and volume-preserving. In this special class of material evolutions, the explicit time dependence of the energy function is via one or more remodeling tensors that can be considered as internal variables of the theory. The governing equations of remodeling solids are derived using a two-potential approach and the Lagrange–d’Alembert principle. We consider both isotropic and anisotropic solids and derive their corresponding remodeling equations. We study a particular remodeling of fiber-reinforced solids in which the fiber orientation is time-dependent in the reference configuration—SO(3)-remodeling. We define an additional remodeling energy, which is motivated by the energy spent in collagen fiber-reinforced living systems to remodel to enhance stiffness or strength in the direction of loading. We consider the examples of a solid reinforced with either one or two families of reorienting fibers and derive their remodeling equations. This is a generalization of some of the proposed remodeling equations in the literature. We study three examples of material remodeling, namely finite extensions and torsion of solid circular cylinders, which are universal deformations for incompressible isotropic solids and certain anisotropic solids. We consider both displacement and force-control loadings. Detailed parametric studies are included for the effects of various material and loading parameters on fiber remodeling. It is observed that during remodeling, there is a competition between the action of the internal strain energy function and the remodeling energy. For a given material, a remodeling process dominated by strain energy works to align fibers in a direction that minimizes strain energy. On the other hand, a remodeling process dominated by the remodeling energy aligns fibers in the direction of the maximum principal strain according to a constitutive choice. We finally linearize the governing equations of the remodeling theory and derive those of linear remodeling mechanics.

Inertial capture of aerosol particles using liquid bridges in cross flow

We investigate the inertial capture of aerosol particles, suspended in a laminar cross flow between parallel plates, by stationary cylindrical liquid bridges. We track the motion and fate of individual aerosol droplets (3–9 μm diameter) suspended in a flow moving across a single liquid bridge or two-bridge systems, using high-speed imaging under a microscope. First, we measure the capture efficiency by inertial impaction of an isolated liquid bridge collector as a function of the aerosol particles Stokes number and show that it agrees with the efficiency calculated for rigid particles moving in a potential flow past a solid cylinder. We then consider two-bridge systems, that is two parallel cylindrical collectors oriented perpendicular to the flow, but offset from each other. We investigate the effect that the upstream collector has on the effective capture efficiency of the downstream test collector, depending on the transverse offset and Stokes number. The offset is the relative displacement of the downstream collector normal to its axis and in the direction perpendicular to the freestream flow. For small values of the transverse offset, smaller than the radius of the collector, small (zero) effective efficiencies are measured for the test collector, due to a partial (complete) shielding effect by the upstream collector. The effective efficiency thus increases from zero with increasing transverse offset, above a threshold value for complete shielding. As the transverse offset increases further, effective efficiencies larger than the efficiency of an isolated bridge are measured for the test collector, showing enhanced capture due to the redistribution of particles moving past the upstream collector. The relative increase in the inertial capture efficiency is significant for Stokes numbers around (but below) unity, 0.45≲St≲0.9, with relative gains as large as approximately 50%. There is an optimum offset displaying maximum effective efficiency and larger offset values lead to a slight decrease in measured efficiencies. These results demonstrate the importance of the relative arrangement of individual collectors on the overall inertial capture efficiency of aerosol particles and suggest that an array of bridges in a slanted configuration (with optimal transverse offsets) could be used as a high-performance filtration system for aerosol particles.

Modified Moore–Gibson–Thompson Thermoelastic Model with Hyperbolic Two Temperatures Effect on Semiconducting Thermoelastic Solid Cylinder

Modified Moore–Gibson–Thompson Thermoelastic Model with Hyperbolic Two Temperatures Effect on Semiconducting Thermoelastic Solid Cylinder

Hygrothermal analysis of a semi-infinite cylinder: an integral transform approach

PurposeThe purpose of this paper is to examine the impact of moisture and temperature changes on the behavior of a semi-infinite solid cylinder made of T300/5208 composite material. This study aims to provide analytical solutions for temperature, moisture and thermal stress through the de-coupling technique and the method of integral transforms. Both coupled and uncoupled cases are considered.Design/methodology/approachThis study investigates the hygrothermo-elastic response of a semi-infinite solid circular cylinder using an integral transform technique that includes Hankel and Fourier transforms. The cylinder is subjected to prescribed sources, and a numerical algorithm is developed for the numerical computation of the results. The goal is to understand how the cylinder responds to changes in temperature and moisture.FindingsThe paper presents an analytical solution for temperature, moisture and thermal stress in a semi-infinite solid cylinder obtained through the use of an integral transform technique. The study focuses on a graphite fiber-reinforced epoxy matrix composite material (T300/5208) and discusses the coupled and uncoupled effects of temperature, moisture and thermal stress on the material. The results of the transient response hygrothermo-elastic field are presented graphically to provide a visual representation of the findings.Research limitations/implicationsThe research presented in this article is primarily hypothetical and focused on the analysis of mathematical models.Originality/valueTo the authors' best knowledge, this study is the first to investigate the hygrothermal effect in a semi-infinite circular cylinder. Additionally, the material properties used in the analysis are both homogenous and isotropic and independent of both temperature and moisture. These unique aspects of the study make it a novel contribution to the field.

Natural convection from solid and hollow cylinders with concave surface: A numerical approach

The buoyancy-driven thermofluid dynamics of a solid/hollow cylinder with concave surfaces have been studied in a laminar regime () using the finite-volume method to analyze the effects of ( and . Conservation equations for mass, momentum, and energy have also been solved in a 2-D axisymmetric geometry . Second-order upwind and central difference schemes have been deployed to discretize the convective and diffusive terms. Heat dissipation increases with irrespective of for both cylinders. However, the remains constant with the ratio for a hollow concave cylinder increases with whereas, decreases. Multiple vortices appear at the outside surface at a low (i.e. = 0.2), and these vortices almost disappear at high (i.e. = 0.6), affecting the outside average Nusselt number from low to high. In all cases, is higher than The thermofluid dynamics of solid and hollow cylinders have been delineated through different countour and vector plots, and two correlations for Nu have been deveoped.