Evaluation of hydrodynamic pressures for autoregression model of irregular waves

A. Degtyarev, I. Gankevich

In the paper a new way of simulating hydrodynamic pressure near ship’s hull is proposed. This approach is based on autoregressive model which is used for wave surface generation. This model offers certain advantages over existing wave wind models. First of all, it enables efficient computation of sea wave elevation compared to linear Longuet-Higgins model. Secondly, it can be used to produce wave fields with arbitrary chosen distribution function via nonlinear inertialess transformation of generated surface. It is important property because investigations show that real waves are characterized by non-Gaussian distribution law. However, autoregressive model is not limited only to generating wave fields and, when extended, this model can also produce pressures and/or velocity potentials within the fluid domain, so that it can be easily used to predict the Froude-Krylov forces on a ship’s hull in a seaway. Such autoregressive approach can substantially reduce complexity of computations required for producing pressures. Knowing pressures is important when solving problem of vessel dynamics in rough sea. So described approach can be employed to solve variety of simulation problems inside a virtual testbed, such as simulation of marine object behavior in irregular waves. Problems of that kind frequently involve large-scale or long-term simulation, that is why it is important to use autoregressive model to reduce computation time. In the paper calculation scheme and complete problem solution as well as test results are provided.

  title={Evaluation of hydrodynamic pressures for autoregression model of irregular waves},
  author={A. Degtyarev and I. Gankevich},
  booktitle={Proceedings of STAB'12},
  address={Athens, Greece},

Publication: Proceedings of STAB'12