Computing ship wave resistance from wave amplitude with a non-local absorbing boundary condition

STORTI, MARIO; D'ELÍA, JORGE; IDELSHON, SERGIO

COMMUNICATIONS IN NUMERICAL METHODS IN ENGINEERING

JOHN WILEY & SONS LTD

Año: 1998 vol. 14 p. 997 - 1012

1069-8299

A method for computing ship wave resistance from a momentum flux balance is presented. It is based on computing the momentum flux carried by the gravity waves that exit the computational domain through the outlet plane.  It can be shown that this method ensures a non-negative wave resistance, in contrast with straightforward integration of the normal pressure forces. However, this calculation should be performed on a transverse plane located far behind theship. Traditional Dawson-like methods add a numerical viscosity that dampens the wave pattern so that some amount of momentum flux is lost, and resulting in an error in the momentum balance. The flow field is computed, then, with a centered scheme with absorbing boundary conditions.