System Description File

The SYSTEM DESCRIPTION FILE is an ASCII file that contains a complete description of the system.

1. System description file layout

The input file is read by the free format reader and decoder FREAD.

Each set of data card or data card group is identified with a character string consisting of maximum 3 words. These are identified by up to maximum four characters in each word.

Comment lines in the input set are obtained by giving an accent (’) in the fist column.

Parameters in a card image are separated by ("space"). Some parameters may have default values. They are obtained simply by giving a slash (/) instead of the input value.

For missing parameters, the default value is used.

Continuation of the card image is obtained by (&).

All numbers given in the input files can be read in free formats, both integer and real numbers. Data types are specified for each input parameter as either integer, real or character, which means that text should be given as input.

Some parameters may have default values. The default values are obtained simply by giving a slash (/) instead of the input value.

The input data are defined by the following input description list:

symbolic names of parameters

  • parameter: format, default: default value: description \(\mathrm {[unit]}\)

  • parameter: format: description

note

  • symbolic names of parameters appear in the order they are decoded

  • item is repeated for all items in the heading

  • description is used for explaining the parameter

  • format is either integer, real or character

  • default value may be indicated (if relevant)

  • unit may be indicated (if relevant)

  • note may be used for comments, etc.

The system description file is divided into 7 main data groups:

  • SYSTem DESCription SIMO: Identifies the file type, always the first data group

  • HLA COMMunication SPECification: Needed only for real-time simulation

  • BODY DATA SPECification: The data group to be repeated for all bodies

  • HYDRodynamic COUPling DATA: The data group to be repeated for each coupling between 2 bodies

  • GENEral LINE DATA: Not to be repeated

  • COUPling DATA: The data group to be repeated for all couplings

  • ENVIronment DATA SPECification: Not to be repeated, environmental conditions must be specified together

  • END: Indicates end of the file

All data within a main data group e.g. BODY DATA SPECification, must be given in one sequence. However the different data groups within a main data group may be given in an arbitrary sequence.