Syntax:
fix ID group-ID seaice/waves wavetype keyword value
region value = region-ID region-ID = ID of region atoms must be in to have added force
Examples:
fix f3v all property/global jonswap vector 0.75 20. 0. 0.33 50. 20 0.05 0.3 5 -14. 14. fix f3 all seaice/waves jonswap fix w2v all property/global regWaves matrix 2 0.75 0.15 25. 18. -5. 5. 0. 20.
Description:
This fix is part of the USER-SEAICE package; it is only enabled if LIGGGHTS was built with that package.
It adds wave-generated force and torque (due to the curvature of the sea surface) to forces/torques acting on each disk-shaped atom in the group.
It is assumed that the wave-induced torque acts in the horizontal plane and results from unbalanced buoyancy forces present if the upper surface of a disk-shaped particle is not parallel to the local sea surface.
This fix requires atom_style hybrid disk disk/waves and, if bonds are used, bond_style gran/disk/waves.
The wavetype option is used to specify the type of wave forcing used in the simulations: either jonswap for a Jonswap spectrum or regWaves for a superposition of regular waves. The wave characteristics for these options have to be specified with a global property jonswap or regWaves, respectively, as in the examples above. The general syntax of these commands is:
fix ID group-ID property/global regWaves matrix N a1 a2 ... aN T1 T2 ... TN th1 th2 ... thN ph1 ph2 ... phN
fix ID group-ID property/global jonswap vector Hs Tp thm gamma m Nf fmin fmax Nd dmin dmax
In the case of the jonswap option, the spectrum specified by the set of parameters Hs, Tp, thm, gamma and m is expressed as a set of Nf*Nd sine waves with random phases and with frequencies logarithmically distributed between fmin and fmax.
The values th1, th2, ..., and thm describe directions to which waves are propagating; zero means waves propagating to the 'east' (positive x-direction), 90 degrees to the 'north' (positive y-direction), -90 degrees to the 'south', and so on.
No default values for the regWaves or jonswap global properties are predifined and the lack of the above definitions in the input script will produce an error.
If the region keyword is used, the atom must also be in the specified geometric region in order to have the force added to it.
Restart, fix_modify, output, run start/stop, minimize info:
See the documentation of the fix addforce command.
Restrictions: none
Related commands:
fix addforce, fix seaice/coriolis, fix seaice/current, fix seaice/wind
Default: none
(Herman) Agnieszka Herman, Geosci. Model Devel., submitted (2015).