A BOUNDARY INTEGRAL APPROACH IN PRIMITIVE VARIABLES FOR FREE SURFACE FLOWS

The boundary integral formulation, very efficient for free surface potential flows, has been considered in the present paper for its possible extension to rotational flows either inviscid or viscous. We analyse first a general formulation for unsteady Navier Stokes equations in primitive variables, which reduces to a representation for the Euler equations in the limiting case of Reynolds infinity. A first simplified model for rotational flows, obtained by decoupling kinematics and dynamics, reduces the integral equations to a known kinematical form whose mathematical and numerical properties have been studied. The dynamics equations to complete the model are obtained for the free surface and the wake. A simple and efficient scheme for the study of the non linear evolution of the wave system and its interaction with the body wake is presented. A steady state version for the calculation of the wave resistance is also reported. A second model has been proposed for the simulation of rotational separated regions, by coupling the integral equations in velocity with an integral equation for the vorticity at the body boundary. The same procedure may be extended to include the diffusion of the vorticity in the flowfield. The vortex shedding from a cylindrical body in unsteady motion is discussed, as a first application of the model.

• Supplemental Notes:
  • Naval Hydrodynamics, 18th Symposium; 19-24 August 1990; Ann Arbor, MI, USA. Sponsored by Office of Naval Res, USA, Univ. Michigan & National Res Council, USA. Pprs. Publ by National Academy Press Washington D.C., USA. 1991, p 221 [17 p, 25 ref, 6 fig]
• Authors:
  • Casciola, C
  • Piva, R
• Publication Date: 1991

Language

• English

Subject/Index Terms

• TRT Terms: Boundary element method; Flow; Free surface; Inviscid fluids; Viscous flow
• Old TRIS Terms: Inviscid flow
• Subject Areas: Marine Transportation; Materials;

Filing Info

• Accession Number: 00701542
• Record Type: Publication
• Source Agency: British Maritime Technology
• Files: TRIS
• Created Date: Aug 14 1995 12:00AM