All programs in the Aqwa suite have a facility for gradual progression through any given analysis. This facility is made possible by structuring each program into a number of distinct stages, called Restart Stages. These are common to all programs in the suite and the user may run, in sequence, any number (there are six stages). Since the restart stages are common to all programs, this allows the user to run more than one program within any analysis (e.g. the user may run the first three stages of Aqwa-Line and then run the last two stages of Aqwa-Fer, to complete a specific type of analysis).
Aqwa-Line can also be used for geometrical scaling when comparing to model tests, and for requesting nodal information related to the radiation/diffraction results.
When the restart facility is invoked, via a program RESTART option (see Administration and Calculation Options for the Aqwa Suite), input information must be supplied from a backing file from a previous program run, and not from the normal data record input file. The required backing files, called restart files, are created automatically when a program is run. This process is also used to transfer information from one program to another so that data input is minimized.
Each of the six Aqwa Restart Stages may be categorized by two classes of activity, which are:
Data Input and Processing of the Data.
Specific Analysis or Post-Processing Activity.
This Aqwa Reference Manual is mainly concerned with the format details required for the data input. The individual Program User Manuals are concerned with the approach that should be adopted for a specific type of motion analysis.
Drag Linearization
There are several types of nonlinear drag in Aqwa, most of which can be linearized and included in the linear programs Aqwa-Line and Aqwa-Fer. TUBE, DISC and STUB elements have drag calculated according to Morison's equation and can be included in both Aqwa-Line and Aqwa-Fer. Hull drag is modeled with drag force coefficients input in Data Category 10. As with most other Stage 4 data, this is not used in Aqwa-Line but can be included in Aqwa-Fer.
For more information, see Morison Drag Linearization in the Aqwa Theory Manual.