Numerically defined spectrum

This is a wave spectrum specified by the user. The spectrum is defined by spectral values and frequencies. Spectral values outside the given frequency range are assumed to be zero. Linear interpolation is used within the frequency range.

The wave spectrum can be specified in an external file.

1. Numerically defined spectrum from file

One input line specifying the number of frequencies and wave directions

NWFRE NWDIR
  • NWFRE: integer: Number of wave frequencies

  • NWDIR: integer: Number of wave directions

One input line specifying the wave directions

WADIR(1) ... WADIR(NWDIR)
  • WADIR: real: Wave propagation direction, \(\mathrm {[deg]}\)

Wave propagation direction (NWDIR+1)/2 is used as average wave direction in DYNMOD in cases where responses are pregenerated in a range around the average direction.

NWFRE lines specifying the wave frequency and wave spectrum values for all directions

WAFREi SPVAL(j,i) ... SPVAL(NWDIR,i)
  • WAFREi: real: Wave frequency no. i, \(\mathrm {[rad}/T]\)

  • SPVAL(j,i): real: Spectrum value for wave frequency no. i and wave direction no. j, \([L^2T/\mathrm{rad]}\)

1.1. Input file example

Lines starting with the symbol ' is treated as a comment

The specified file must contain:

'---------------------------------------------------------------
' START OF FILE
'---------------------------------------------------------------
' NWFRE = Number of wave frequencies
' NWDIR = Number of wave directions
'---------------------------------------------------------------
'nwfre nwdir
 25    24
'---------------------------------------------------------------
' WADIR_j =  real: Wave propagation direction, [deg]
'---------------------------------------------------------------
' WADIR_1 ... WADIR_j ...  WADIR_nwdir
'
2 17 32 47 62 77 92 107 122 137 152 167 182 197 212 227 242 257 272 287 302 317 332 347
'---------------------------------------------------------------
' WAFRE_i   = Wave frequency no. i, [rad/s]
' SPVAL_j,i = Spectrum value no. ji [m**2 s/rad]
'---------------------------------------------------------------
' WAFRE_i SPVAL_1,i ...... SPVAL_j,i ... SPVAL_nwdir,i
'
0.263893783	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0
0.290283161	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0
0.319185814	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	2.60E-04	2.60E-04	0	0	2.60E-04	0	0	0	0
0.351230059	0	0	0	0	0	0	0	0	0	0	0	0	0	0	7.90E-04	0.00602	0.01047	0.00157	2.60E-04	0.00576	0.00314	7.90E-04	0	0
0.386415896	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0.00497	0.04294	0.14608	0.13352	0.01047	0.04424	0.02749	0.01518	0.00471	5.20E-04
0.424743327	0.00157	2.60E-04	0	0	0	0	0	0	0	0	0	0	0	5.20E-04	0.01257	0.09006	0.30683	0.96237	0.20211	0.10105	0.09765	0.15499	0.06807	0.01073
0.467468987	0.01754	0.00209	2.60E-04	5.20E-04	0	0	0	0	0	0	0	0	0	0.00131	0.01257	0.11153	0.70319	2.92142	1.97894	0.44558	0.26756	0.25892	0.16441	0.08666
0.513964558	0.0589	0.01073	0.00105	0.00157	0	0	0	0	0	0	0	0	2.60E-04	0.00262	0.01623	0.14111	1.0506	4.81816	4.53594	2.17974	1.01814	0.38249	0.26677	0.31128
0.565486678	0.06178	0.01702	0.00262	7.90E-04	0	0	0	0	0	0	0	0	5.20E-04	0.00445	0.0267	0.19268	1.39199	4.82522	5.46244	4.45975	3.85212	1.04406	0.4982	0.42987
0.622035345	0.08299	0.0178	0.00262	0.00105	0	0	0	0	0	0	0	0	0.00131	0.00838	0.06964	0.42019	1.04877	2.88163	4.4375	3.09421	2.93111	2.17948	1.23726	0.57779
0.68423888	0.14713	0.02618	0.0034	0.00131	0	0	0	0	0	0	0	2.60E-04	0.00183	0.01518	0.13561	0.3961	0.68303	1.59933	2.69156	1.86715	1.50508	1.3467	1.32628	0.76917
0.7527256	0.17331	0.03325	0.00445	0.00105	0	0	0	0	0	0	0	2.60E-04	0.00236	0.02539	0.1542	0.3139	0.50396	0.90897	1.24407	1.21213	0.9451	0.7443	0.57439	0.50527
0.828123823	0.12933	0.03299	0.00419	5.20E-04	0	0	0	0	0	0	0	2.60E-04	0.00236	0.02827	0.14582	0.26861	0.41364	0.73356	0.87389	0.83854	0.67466	0.54795	0.41888	0.29243
0.91106187	0.10393	0.02618	0.0034	2.60E-04	0	0	0	0	0	0	0	0	0.00183	0.02644	0.12488	0.22436	0.35579	0.59952	0.68408	0.61732	0.48904	0.39139	0.32515	0.2296
1.002168056	0.08849	0.02199	0.00262	2.60E-04	0	0	0	0	0	0	0	0	0.00157	0.02173	0.09739	0.18404	0.31337	0.45003	0.50894	0.47019	0.39322	0.2885	0.22881	0.16781
1.102070703	0.06231	0.01806	0.00183	0	0	0	0	0	0	0	0	0	0.00105	0.01676	0.07173	0.13561	0.23536	0.31285	0.34348	0.31023	0.26573	0.20289	0.15053	0.11074
1.212654764	0.04006	0.01257	0.00131	0	0	0	0	0	0	0	0	0	0.00105	0.01283	0.05	0.09687	0.16415	0.20918	0.22331	0.20106	0.17253	0.13614	0.09713	0.07121
1.333920241	0.02513	0.00812	7.90E-04	0	0	0	0	0	0	0	0	0	7.90E-04	0.00995	0.03508	0.07016	0.11153	0.13456	0.13797	0.12933	0.11336	0.09032	0.06178	0.04398
1.467123769	0.01545	0.00497	5.20E-04	0	0	0	0	0	0	0	0	0	5.20E-04	0.00733	0.02513	0.05105	0.07671	0.08927	0.08901	0.08482	0.07645	0.06205	0.0411	0.02723
1.614150305	0.00916	0.00288	2.60E-04	0	0	0	0	0	0	0	0	0	5.20E-04	0.0055	0.01806	0.03665	0.0521	0.05838	0.0576	0.0555	0.05131	0.04241	0.02775	0.01702
1.775628168	0.00497	0.00157	0	0	0	0	0	0	0	0	0	0	2.60E-04	0.00393	0.01283	0.02566	0.03482	0.03744	0.03691	0.03639	0.03456	0.0288	0.01859	0.01047
1.952813993	0.00262	7.90E-04	0	0	0	0	0	0	0	0	0	0	2.60E-04	0.00262	0.0089	0.01728	0.02225	0.0233	0.0233	0.02304	0.02225	0.01885	0.0123	0.00628
2.148221057	0.00131	2.60E-04	0	0	0	0	0	0	0	0	0	0	2.60E-04	0.00183	0.00576	0.011	0.01388	0.0144	0.0144	0.01466	0.01414	0.0123	0.00785	0.00367
2.363105994	5.20E-04	0	0	0	0	0	0	0	0	0	0	0	0	0.00105	0.00367	0.00707	0.00838	0.0089	0.0089	0.00916	0.0089	0.00759	0.00497	0.00209
2.599353762	2.60E-04	0	0	0	0	0	0	0	0	0	0	0	0	7.90E-04	0.00236	0.00419	0.00524	0.0055	0.0055	0.00576	0.0055	0.00471	0.00314	0.00131
'
'---------------------------------------------------------------
' END OF FILE
'---------------------------------------------------------------