Session: 06-05-03 Marine Hydrodynamics III

Paper Number: 80174

80174 - Use of a Linear Discretization of the Velocity Potential in the Frequency-Domain Linear Potential Flow Theory 

Diffraction-radiation codes are fundamental tools for evaluating the wave-structure interaction of floating or immersed bodies in seakeeping or maneuverability, with or without foward speed, during numerical simulations. They are based on the linear potential flow theory in frequency-domain. Most of these solvers are based on the boundary element method and assume that the velocity potential is constant over each panel of the mesh. This approach is named the Constant Panel Method (CPM). It is efficient but suffers of a lack of accuracy on high-curvature surfaces. Consequently, it is necessary to increase the number of panels to reach an acceptable accuracy but at the cost of a rise of the CPU time and memory requirements. To overcome this problem, the High-Order Boundary Element Method (HOBEM) has been developed. Contrary to the CPM, the velocity potential is evaluated based on shape functions at several points of each panel, including its vertices. This method ensures the continuity of the derivatives, the numerical results are more accurate and hence meshes may be coarser. Nevertheless, this high-order approach requires more computations per panel and is more complex to handle mathematically and numerically.
 

This study investigates an intermediate appraoch based on the use of a linear discretization of the velocity potential in a frequency-domain potential flow based solver. The velocity potential is assumed to vary linearly over each panel. This approach differs from the Constant Panel Method or the High-Order Boundary Element Method. The linear discretization is studied as a possible intermediate strategy between these two latter methods in term of accuracy and CPU time.

The first objective of this paper is the development of the frequency-domain linear potential theory based on the linear discretization of the velocity potential. The second objective is the quantification of such a change compared to the classical Constant Panel Method.

Presenting Author: Pierre-Yves Wuillaume D-ICE Engineering

Authors:

Pierre-Yves Wuillaume D-ICE Engineering
Lucas Letournel D-Ice Engineering
François Rongère D-Ice Engineering
Camille Chauvigné D-Ice Engineering