In this paper, 3-dimensional linear instability analysis has been carried out for unsteady pipe flow. An inflectional velocity profile from [2] has been considered and the stability analysis of it has been carried out for (axisymmetric mode) and 0 = n 2 & 1 = n . It was revealed that the profile is unstable for both axisymmetric and non-axisymmetric modes. The mode 1 = n was observed to be most...

A 2D (axisymmetric) computational study of the discharge characteristics of an atmospheric pressure plasma jet as a function of gas flow rate was performed. The helium jet emerged from a dielectric tube, with an average gas flow velocity in the range 2.5–20 m s−1 (1 atm, 300 K) in a nitrogen ambient, and impinged on a substrate a short distance dowstream. The effect of the substrate conductivit...

We find closed-form solutions for axisymmetric plane strain radial deformations of a functionally graded circular hollow cylinder and radial expansion/contraction of a hollow sphere loaded on inner and outer surfaces by uniform hydrostatic pressures. The cylinder and the sphere are presumed to be made of isotropic and incompressible linear elasticmaterials with the shearmodulus a general functi...

The Abel inversion, used to reconstruct axisymmetric radial profiles from line-of-sight intensity measurements, is increasingly used to make spatially resolved combustion measurements. An Abel deconvolution is valid only when incoming rays are parallel, whereas most practical optical setups used for emission imaging consist of single-lens and multilens systems that collect light in a cone, over...

Acoustic waves in a rigid axisymmetric tube with a variable cross-section are considered. The governing Helmholtz equation is solved using Neumann series (expansions in Bessel functions of various orders) with a stretched radial coordinate, leading to a hierarchy of one-dimensional ordinary differential equations in the longitudinal direction. The lowest approximation for axisymmetric motion in...

Radial forging is an open die forging process used for reducing the diameters of shafts, tubes, stepped shafts and axles and also for creating internal profiles such as rifling the gun barrels. The radial forging of tube is usually performed over a mandrel to create an internal profile and/or size the internal diameter. Most of the previous studies conducted on the radial forging process have u...

Context. The high-frequency quasi-periodic oscillations (HF QPOs) in neutron star and stellar-mass black hole X-ray binaries may be the result of a resonance between the radial and vertical epicyclic oscillations in strong gravity. Aims. In this paper we investigate the resonant coupling between the epicyclic modes in a torus in a strong gravitational field. Methods. We perform numerical simula...

The analytical solution of functionally graded piezoelectric hollow cylinder which is under radial electric potential and non-axisymmetric thermo-mechanical loads, are presented in this paper. Using complex Fourier series and estimation of power law for variations of material characterizations through the thickness, the electro thermo mechanical behavior of the FGPM cylinder is obtained. The st...

Sound waves along a rigid axisymmetric tube with a variable cross-section are considered. The governing Helmholtz equation is solved using power-series expansions in a stretched radial coordinate, leading to a hierarchy of one-dimensional ordinary differential equations in the longitudinal direction. The lowest approximation for axisymmetric motion turns out to be Webster’s horn equation. Fourt...

In this article we investigate the numerical approximation of the Darcy equations in an axisymmetric domain, subject to axisymmetric data. Rewriting the problem in cylindrical coordinates reduces the 3-D problem to a problem in 2-D. This reduction to 2-D requires the numerical analysis to be studied in suitably weighted Hilbert spaces. In this setting the Raviart-Thomas (RT) and Brezzi-Douglas-...