The shape of a cusped galactic nucleus is constrained by the range of shapes of orbits in its gravitational potential. It is shown for scale-free non-axisymmetric discs that while a plausible elongated density model requires at least some orbits to spend more time near the major axis than anywhere else, both regular boxlets and tube orbits generally cross the major axis too fast for self-consis...

The purpose of introducing ultrasonic vibrations in the tube hydroforming process is to create more formability by obtaining a lower corner radius, improve thickness distribution of the wall and provide good tribological conditions at the tube and the die interface. Vibrations imposed on the die create alternating gaps which improve the formability in the tube hydroforming process in the presen...

In this research, the convective heat transfers of turbulent water fluid flow in alternating oval tubes is studied using computational fluid dynamics. The purpose of the study is to analyze the heat transfer enhancement and secondary internal flows under different alternate angles. Also, comparing the effect of two schemesfor the domain discretization to be used in the soluti...

This paper investigates the propagation of an air finger into a fluid-filled, axially uniform tube of elliptical or rectangular cross section with transverse length-scale a and aspect ratio α. Gravity is assumed to act parallel to the tube’s axis. The problem is studied numerically by a finite-element-based direct solution of the freesurface Stokes equations. In rectangular tubes, our results f...

Abstract We present a detailed analysis of the behavior triaxial Schwarzschild orbit superposition method near axisymmetric limit. Orbit modeling is primary used to determine dynamical masses supermassive black holes ( M BH ) in nearby galaxies; however, prior studies have reported conflicting results when comparing outcome from codes with that code show order achieve (oblate) axisymmetry code,...

An alternating method, in conjunction with the finite element method and a newly developed analytical solution for an elliptical crack in an infinite solid, is used to determine stress intensity factors for semi-elliptical surface flaws in cylindrical pressure vessels. The present finite element alternating method leads to a very inexpensive procedure for routine evaluation of accurate stress i...

A fast and robust ellipse-detection method based on sorted merging is proposed in this paper. This method first represents the edge bitmap approximately with a set of line segments and then gradually merges the line segments into elliptical arcs and ellipses. To achieve high accuracy, a sorted merging strategy is proposed: the merging degrees of line segments/elliptical arcs are estimated, and ...