A Nonlinear Frequency Domain Simulation for SWATH Craft,
Abstract
The development of a nonlinear frequency domain simulation which accommodates frequency independent nonlinearities is described. Although developed around the dynamics of a particular naval craft, the simulation can be applied to the most general situation and need not be restricted solely to the prediction of ship motions. The workability and usefulness of the simulation is demonstrated by carrying out three scenarios with the SWATH 6A craft. Two scenarios are open loop; the third includes automatic control. These scenarios are also simulated in the time domain using a generalized nonlinear time domain simulation which is based on the same modeling of the craft dynamics that is used for the nonlinear frequency domain simulation. The results obtained with these simulations agree for each of the scenarios simulated. When the results obtained with the nonlinear frequency domain simulation are contrasted with those obtained with a linear frequency domain simulation which employs equivalent linearization, the lack of agreement is noticeable. This highlights the limited usefulness of equivalent linearization. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Mar 01, 1980
- Accession Number
- ADA084674
Entities
People
- David W Taylor
- Walter H. Livingston