Child pages
  • Hydrodynamic bodies
Skip to end of metadata
Go to start of metadata

aNyMoor is delivered with a set of HYD-files with hydrodynamic coefficients. These coefficients are calculated with MARIN's inhouse developed package DIFFRAC and comprise added mass, potential damping and transfer functions for first and second order (drift) wave forces for a number of wave frequencies and wave directions. The coefficients are calculated for a specific draft and waterdepth.
Apart from the hydrodynamic coefficients the HYD-file contains also hydrostatic data: draft, waterdepth, displacement, waterline area, flotation and buoyancy position and the transverse and longitudinal metacentric heights. The hydrostatic data is used for the calculation of the hydrostatic springs for heave, roll and pitch.

Specific for aNyMoor extra data has been added in the HYD-files. This data has been put at the 15 comment lines at the top of each HYD-file, recognizable by the keyword "IDENT". Below an example is shown:

The following data is read from the IDENT records:

  • LPP
  • B
  • XCOG
  • ZCOG
  • KXX
  • KYY
  • KZZ

The sequence of these properties is free. Their values must be given after the colon.  

The draft is read from the REFS record. The displacement, the transverse metacentric height KMt and longitudinal metacentric height KMl are read from the SPRING record.

All the above mentioned properties are shown at the "Ship data" panel.

A HYD-file can contain coefficients of upto 3 bodies (not supplied with aNyMoor). Such a multi-body HYD-file has been made for one specific configuration of two or three bodies. Care must be taken that:

  • the correct body index is set in the GUI for each vessel;
  • the multi-body configuration in a simulation is equal, or at least very close, to the configuration for which the HYD-file has been made. This is important because the distance between the vessels and their orientations determine the magnitude and phase of the hydrodynamic interactions.

HYD-files can be generated by MARIN on request. It is also possible to use another diffraction package, like WAMIT, as long as the format of the HYD-file is correct.

Termsim HYD-files

There are 60 HYD-files for Termsim each covering one specific tanker in a specific condition. There are four different tankers:

Length [m]325.00325.00286.40310.00
Width [m]65.0053.6043.7047.17
 100% loading condition
Draft [m]22.3022.1615.8018.90
Displacement [m3]392,400329,700164,500234,994
 70% loading condition
Draft [m]15.6115.5111.0613.23
Displacement [m3]268,300225,900111,500159,698
 40% loading condition
Draft [m]8.928.866.327.56
Displacement [m3]155,400125,90062,20088,956

For each tanker three loading conditions are present; 100% (fully loaded), 70% and 40% of the fully loaded draft. For each of these tankers and loading conditions the water depth to draft ratio WD/T varies:

    WD/T = 20.0 - 5.0 - 3.0 - 1.5 - 1.2

This totals the number of cases to 4 (tanker) x 3 (loading) x 5 (WD/T ratios) = 60 cases.

The names of the HYD-files are composed as follows:


in which: i = number of tanker 1, 2, 3 or 4

              j = number of loading condition 1 = 100%, 2 = 70%, 3 = 40%

              k = number of water depth to draft ratio 1 = 20.0, 2 = 5.0, 3 = 3.0, 4 = 1.5, 5 = 1.2

Besides the 60 tanker bodies, an SPM buoy is added to the database, including its damping file.

Dynfloat HYD-files

For Dynfloat there are 6 HYD-files delivered with aNyMoor. They comprise 3 tankers at 2 drafts: 100% and 40%, all for a waterdepth of 1000 m:

Length [m]310.00285.00305.45
Width [m]44.1741.4053.50
 100% loading condition
Draft [m]18.9018.5020.00
Displacement [m3]234,994205,922282,000
 40% loading condition
 Draft [m] 7.567.408.00 
 Displacement [m3]88,95679,937106,000


Reference is made to aNyWiki's Bodies for more information.






  • No labels