Arama Sonuçları

Listeleniyor 1 - 3 / 3
  • Yayın
    Weakly nonlinear waves in a prestressed thin elastic tube containing a viscous fluid
    (Pergamon-Elsevier Science Ltd, 1999-11) Antar, Nalan; Demiray, Hilmi
    In this work, we studied the propagation of weakly nonlinear waves in a prestressed thin elastic tube filled with an incompressible viscous fluid. In order to include the geometrical and structural dispersion into analysis, the wall's inertial and sheer deformation are taken into account in determining the inner pressure-inner cross sectional area relation. Using the reductive perturbation technique, the propagation of weakly nonlinear waves, in the long-wave approximation, is shown to be governed by the Korteweg-de Vries-Burgers (KdVB) equation. Due to dependence of coefficients of the governing equation on the initial deformation, the material and viscosity parameters, the profile of the travelling wave solution to the KdVB equation changes with these parameters. These variations are calculated numerically for some elastic materials and the effects of initial deformation and the viscosity parameter on the propagation characteristics are discussed.
  • Yayın
    Waves in fluid-filled elastic tubes with a stenosis: Variable coefficients KdV equations
    (Elsevier B.V., 2007-05-15) Demiray, Hilmi
    In the present work, by treating the arteries as thin-walled prestressed elastic tubes with a stenosis and the blood as an inviscid fluid we have studied the propagation of weakly nonlinear waves in such a medium, in the longwave approximation, by employing the reductive perturbation method. The variable coefficients KdV and modified KdV equations are obtained depending on the balance between the nonlinearity and the dispersion. By seeking a localized progressive wave type of solution to these evolution equations, we observed that the wave speeds takes their maximum values at the center of stenosis and gets smaller and smaller as one goes away from the stenosis. Such a result seems to reasonable from the physical point of view.
  • Yayın
    A certain class of starlike log-harmonic mappings
    (Elsevier Science BV, 2014-11) Aydoğan, Seher Melike; Polatoğlu, Yaşar
    In this paper we investigate some properties of log-harmonic starlike mappings. For this aim we use the subordination principle or Lindelof Principle (Lewandowski (1961) [71).