International Journal for Numerical Methods in Fluids

Cover image for Vol. 74 Issue 8

20 March 2014

Volume 74, Issue 8

Pages 543–622

  1. Research Articles

    1. Top of page
    2. Research Articles
    1. Towards consistent hybrid overset mesh methods for rotorcraft CFD (pages 543–576)

      M. Jarkowski, M.A. Woodgate, G.N. Barakos and J. Rokicki

      Version of Record online: 28 NOV 2013 | DOI: 10.1002/fld.3861

      Thumbnail image of graphical abstract

      A novel method for overset mesh solution localisation is presented in this paper, based on three key components: 1) The use of a pre-localisation method to reduce the required searches for bloc-to-block overlaps on multi-block structured grids. 2) A representation of the CFD mesh as a binary tree for fast point-in-box checks. 3) An exact arithmetics library to preserve accuracy for point co-ordinate comparisons. The results show minimal overhead in terms of CPU time and are compared for accuracy against matching grid results or against sliding grid methods. The method was effective for a range of test cases from simple aerofoils to rotor/fuselage configurations.

    2. A modular, operator-splitting scheme for fluid–structure interaction problems with thick structures (pages 577–604)

      M. Bukač, S. Čanić, R. Glowinski, B. Muha and A. Quaini

      Version of Record online: 10 DEC 2013 | DOI: 10.1002/fld.3863

      Thumbnail image of graphical abstract

      A novel stable, modular, operator-splitting scheme is presented for the simulation of fluid-structure interaction (FSI) problems in which the structure has finite thickness, comparable to the transverse dimension of the fluid domain. The fluid flow is modeled by the Navier-Stokes equations for an incompressible, viscous fluid, while the structure elastodynamics is governed by the equations of linear elasticity/viscoelasticity. Energy estimates associated with unconditional stability of the scheme are shown for the full, nonlinear FSI problem. Numerical examples show that this modular scheme compares well with monolithic schemes.

    3. A semi-implicit numerical method for the free-surface Navier–Stokes equations (pages 605–622)

      Vincenzo Casulli

      Version of Record online: 28 NOV 2013 | DOI: 10.1002/fld.3867

      Thumbnail image of graphical abstract

      A semi-implicit method for complex free-surface flows that are governed by the incompressible Navier–Stokes equations is derived and discussed. Finite difference equations for momentum and a finite volume discretization for continuity are derived in such a fashion that, after simple manipulation, the resulting pressure equation yields a well-posed piecewise linear system from which both the pressure and the corresponding fluid volumes are determined simultaneously. This system is efficiently solved by a specifically devised nested iterative scheme, and the resulting fluid volumes are assured to be nonnegative and bounded for any time step size.