On the Propagation of Acceleration Waves in Circular Cylindrical Elastic Membrane Tubes Subjected to Axial Extension

Time-fractional effect on pressure waves propagating through a fluid filled circular long elastic tube

The propagation and growth of acceleration waves in an incompressible thermoelastic solid in which constitutive equations also depend on the temperature rate are investigated. The speeds of propagation and the growth equations are obtained in explicit forms in the case of isotropic materials. Uncoupled growth equations of acceleration and thermal waves propagating in principal directions are integrated by assuming the medium is at rest and in thermal equilibrium ahead of the wave front. Shock formation is examined for some special waves.

Propagation of acceleration waves in micropolar elastic solids

Cylindrical tubes and membranes are universal structural elements found in biology and engineering over a wide range of scales. Working in the framework of nonlinear elasticity, we consider the possible deformations of elastic cylindrical shells reinforced by one or two families of fibres. We consider both small and large deformations and the reduction from thick cylindrical shells (tubes) to thin shells (cylindrical membranes). In particular, a number of universal parameter regimes can be identified where the response behaviour of the cylinder is qualitatively different. This include the possibility of inversion of twist or axial strain when the cylinder is subject to internal pressure.

On the flexural rigidity of a micropolar elastic circular cylindrical tube

The propagation of acceleration waves in dilute granular gases was investigated. Acceleration waves propagating in elastic gases, mixtures, and other materials are widely studied in the literature, but not in granular gases. A thirteen-moment theory for granular gas was considered in the framework of Grad’s theory. The spatially homogeneous solutions were determined, and the hyperbolicity of the model is discussed. The propagation of acceleration waves in a non-constant state was investigated; the amplitude of the fastest mode was derived, and the critical time was evaluated. The acceleration wave propagation velocity in inelastic gases was shown to be lower than in elastic gases.

A study of self-propelled elastic cylindrical micro-swimmers using modeling and computation

Bifurcation of rotating thick-walled elastic tubes

Wrinkling of inflated elastic cylindrical membranes under flexure

On the propagation of acceleration waves in incompressible hyperelastic solids

A numerical method employing an upwind finite-difference technique is adopted for an investigation of peristaltic pumping in circular cylindrical tubes. such as some organs in the living body. Various peristaltic flows are calculated under conditions of finite wave amplitudes, finite wavelengths and finite Reynolds numbers, and the influence of the magnitude of these quantities on the flow is investigated. The fluid mechanics of peristaltic mixing and transport are studied in detail by analysing the reflux and the trapping phenomena. The mechanical efficiency of peristaltic pumping is also discussed, with reference to engineering and physiological applications. It is shown that quantitative differences are observed between the results obtained for flows in a circular cylindrical tube and a two-dimensional plane channel. However, for both cases the appearance of peristaltic reflux depends upon the Reynolds number and the wavenumber (mean tube radius/wavelength). Much greater peristaltic mixing and transport are realized in a circular tube than in a plane channel.

This paper deals with modeling of nonlinear plane acoustic waves propagating through an elastic tube filled with thermoviscous gas. A description of the interactions between gas and an elastic tube wall is carried out by the continuity equation of a wall velocity. Simplification on the basis of the local reaction assumption enables to model an acoustic treatment on the tube wall by using a wall impedance. Because there are considerable losses due to wall friction, the influences of the acoustic boundary layer were also considered. Using certain assumptions a special form of the Burgers equation was derived which enables to describe the propagation of nonlinear waves in the elastic tube. This model equation takes into account nonlinear, dissipative, and dispersion effects which compete each other. Characteristic lengths of the supposed effects and numerical results with respect to the source frequency were used for a qualitative analysis of the model equation. Applicability of this model equation was demonstrated by series of measurements. By application of the long-wave approximation the Korteweg-de Vries-Burgers and Kuramoto-Sivashinsky equations were derived from the modified Burgers equation.

Thermodynamic influences on the propagation of waves in electroelastic materials

On the propagation of acceleration waves in vibrational and radiative nonequilibrium magnetogasdynamic flows

Acoustic radiation force effect upon a rigid spherical particle placed in the thin elastic tube is studied. The problem of determination of the acoustic radiation forces acting on an obstacle in an ideal liquid is formulated with respect to the Lagrange coordinate system. Thus, the radiation pressure is defined as time-averaged value of the acoustic pressure over the obstacle surface. This approach is adequate if, at determining of the acoustic pressure in a fluid, the deviation of the pressure from the harmonic law in time domain is taken into account in the obstacle vicinity. An action of the acoustic radiation force on the rigid spherical particle placed in the thin tube with elastic wall is studied here for the case of the incident plane sound wave propagating along the tube axis. Model is developed to describe the response of the system consisting of the compliant infinite thin circular cylindrical tube filled with the ideal compressible liquid and rigid spherical body which is immovable and located on the tube axis under the plane wave propagating along the tube axis. The problem of the hydrodynamic characteristics determination is reduced to the solution of the infinite system of algebraic equations that can be solved by the reduction method. The formula for the acoustic radiation force calculation is derived to characterize the force acting upon rigid spherical particle in the thin compliant elastic cylindrical tube.