Ocean waves are an essential input for calculation of wave loads and response of marine structures. Traditionally, when it comes to irregular waves, analysis has been limited to linear, or at most, second order irregular waves. These theories fail to describe important nonlinear dynamic interaction between wave components, which may have an important impact on the statistical properties of the waves, for example, the occurrence of so called rogue or freak waves. In order to get more realistic description of waves and their associated effects on loads and responses, a nonlinear description is needed. In contrast to linear or second order theories where analytical solutions are available, higher order nonlinear waves must be described through numerical simulations of the basic hydrodynamic equations.

Using DNV's Wasim and Wamod programs will allow an efficient sea-keeping computation of both linear and nonlinear random seas, and also facilitate the use of the same sea-state realization in different tools.

In this webinar we will go through the theory behind Wamod, Higher Order Spectral Method (HOSM). The interface options between Wamod and Wasim will be explained and benefits of using Wamod generated wave kinematics as input to Wasim will be demonstrated by some examples. The Spectral Wava Data (SWD) format and its interface to other tools will be shown in the end.  Join this webinar as we will demonstrate how to use the new product and new features to carry out linear and nonlinear hydrodynamic analyses in random sea states.

Topics covered:

• Challenges and background
• Why Wamod and HOSM
• Basic theory of HOSM
• Benefits of using Wamod/Wasim
• Examples and testing 
• Short introduction to SWD interface

About the speakers:

• Torgeir Vada has been working in DNV since 1985, when he achieved a PhD in Hydrodynamics from the University of Oslo. He has worked with Sesam since 1997, first as a developer and then in various line manager positions. He is currently Product Manager for Floating Structures.
• KaiJai Han has been working in DNV at Høvik since 2008 and had a background of Hydrodynamics covering ship resistance, propulsion, seakeeping, testing and CFD. She has been responsible for developing, maintaining and supporting the hydrodynamic product Wasim.