Random Seed |
 
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Random Seed |
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Flexcom uses a random number generator to assign phase values to harmonics in a discretised wave spectrum or spectra. Unless you specify otherwise, Flexcom always uses the same seed value, so that every time you discretise the same spectrum with the same discretisation parameters, you get the same sequence of random phases and consequently the same time history of water surface elevation. You may want to change this, so that you get a different set of phases and so a different wave elevation time history from the same spectrum and discretisation parameters (other than the seed). This can be done by specifying a different seed value.
Flexcom uses a Multiplicative Congruential Generator to generate a sequence of random phases. For best results, the random number seed for this should be a large (and preferably prime) number. You may enter your own value for the random number seed. Alternatively, you can select a seed value from a prepared list which Flexcom provides.
Specifying a random number seed is optional. If you do not specify a value, Flexcom uses the first value in the list by default.
Naturally, invoking this option is meaningful only in the case of a time domain dynamic analysis with a random wave spectrum or spectra. If your analysis includes two spectra, any seed value you input will be used in discretising both.
•*WAVE-GENERAL is used to specify miscellaneous parameters to wave loading. Specifically, the SEED= input is used to specify a seed value for the random number generator that assigns random phases to wave components when discretising a wave spectrum.