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Importing hydrodynamic data: WADAM |
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Importing hydrodynamic data: WADAM |
The easiest way to import from WADAM into OrcaFlex is to save the results in WAMIT format, an option available in more recent versions of WADAM. You should be aware that complete WAMIT-format files are not saved by default in WADAM, and you must follow a specific procedure to obtain such a file. The procedure for creating a complete WAMIT .out file from WADAM is described in the WADAM manual for versions which allow this option (v9.2 onwards). Once you have a WAMIT-format output file, OrcaFlex will recognise it as such and import it as it does native WAMIT .out files, with no need for any markup or other editing of the results file.
If the WAMIT format option is not available to you, the data can be imported from WADAM but will need some manipulation and some mark-up text to get them into the format required by OrcaFlex: if at all possible, we recommend that you follow the WAMIT-format route as this should be less error-prone. If this is not possible then you should refer to the remainder of this topic, which describes the ways in which you need to manipulate native WADAM files in order to import their data into OrcaFlex.
OrcaFlex is not able to import any WADAM RAO data directly: WADAM displacement and load RAO tables have the 6 degrees of freedom arranged as rows rather than columns, and it is not possible to mark up this format in a way which is consistent with the required OrcaFlex headers. So we suggest that you read the file into Excel (or similar), transpose each of the RAO tables and add the required mark-up text, and save the file as text. This file can then be imported in the usual way.
Newman QTFs, as for RAOs, are transposed by WADAM from the format required by OrcaFlex. And, again as for RAOs, you can transpose each table of QTFs in Excel or similar and add the required markup text to each.
Full QTFs cannot be imported in a straightforward way from WADAM. They are written to the WAMIT-format .out file, but WADAM uses an early version of WAMIT so it does not output a complete set of full QTFs by this method. And the generic text format does not, unfortunately, support full QTFs.
WADAM's native output does include $6{\times}6$ added mass and damping matrices in a non-dimensional form which can be imported by OrcaFlex with the required markup, so long as the non-dimensionalising factors are specified in the file.
Since the data are fully non-dimensional, the scaling is rather complex: the factors differ between the added mass and damping matrices, and each matrix requires a different factor for each constituent $3{\times}3$ sub-matrix (since their units differ). Full details of the calculation of these factors are given in the WADAM output file itself (search for the string 'non-dimensional'); see the example below, which shows the relevant text and the corresponding markup text required by OrcaFlex.
| Warning: | Remember that you must ensure that the units of your re-dimensioned WADAM added mass and damping data, are consistent with your OrcaFlex model units. If your OrcaFlex and WADAM units differ, you should be able to take account of the difference by modifying the scaling factors accordingly. |
[…]
4.1 EXPLANATION OF THE RESULTS
------------------------------
NON-DIMENSIONAL DEFINITIONS:
---------------------------- I=1-3 I=1-3 I=4-6 I=4-6
J=1-3 J=4-6 J=1-3 J=4-6
MASS INERTIA MATRIX NON-DIMENSIONALIZED BY: RO*VOL, RO*VOL*L RO*VOL*L*L
ADDED MASS MATRIX NON-DIMENSIONALIZED BY: RO*VOL, RO*VOL*L RO*VOL*L*L
DAMPING MATRIX NON-DIMENSIONALIZED BY: RO*VOL*SQRT(G/L) RO*VOL*SQRT(G*L) RO*VOL*L*SQRT(G*L)
RESTORING MATRICES NON-DIMENSIONALIZED BY: RO*VOL*G/L, RO*VOL*G RO*VOL*G*L
[…]
NON-DIMENSIONALIZING FACTORS:
-----------------------------
THE OUTPUT IS NON-DIMENSIONALIZED USING -
RO = DENSITY OF THE FLUID
G = ACCELERATION OF GRAVITY
L = CHARACTERISTIC LENGTH, AS GIVEN IN THE INPUT
VOL = DISPLACED VOLUME OF BODY 1 (COMBINED MORISON AND PANEL MODEL)
WA = WAVE AMPLITUDE OF THE INCOMING WAVES
RO = 0.1025E+04
G = 0.9810E+01
VOL = 0.7847E+04
L = 0.1000E+02
WA = 1.0 (IF NOT GIVEN AS INPUT)
[We use the above information to generate the following re-dimensionalising factors:]
*** OrcaFlex Added Mass Scaling Factor Start ***
TopLeft=8043175
TopRight=80431750
BottomRight=804317500
*** OrcaFlex Added Mass Scaling Factor End ***
*** OrcaFlex Damping Scaling Factor Start ***
TopLeft=7966398
TopRight=79663980
BottomRight=796639800
*** OrcaFlex Damping Scaling Factor End ***
*** OrcaFlex Conventions Start ***
SurgePositive = forward
SwayPositive = port
HeavePositive = up
RollPositiveStarboard = down
PitchPositiveBow = down
YawPositiveBow = port
*** OrcaFlex Conventions End ***
-4.3- WAVE LENGTH NO.: 1
PAGE NO.: 1
+------------------------------------------------+
:+----------------------------------------------+:
:: ::
:: W A V E L E N G T H = 1.4052E+01 ::
:: ::
:: W A V E P E R I O D = 3.0000E+00 ::
:: ::
:: ::
:+----------------------------------------------+:
+------------------------------------------------+
ADDED MASS MATRIX
-----------------
*** OrcaFlex Added Mass Matrix Start ***
Draught WadamDraught
WP 3
1 2 3 4 5 6
1 2.7488E-02 0.0000E+00 4.4755E-02 0.0000E+00 1.7670E+00 0.0000E+00
2 0.0000E+00 1.8301E-01 0.0000E+00 -1.2993E-01 0.0000E+00 -3.2616E-01
3 4.8308E-02 0.0000E+00 1.0474E+00 0.0000E+00 1.6820E+00 0.0000E+00
4 0.0000E+00 -1.7738E-01 0.0000E+00 6.5866E+00 0.0000E+00 5.5181E+00
5 1.8650E+00 0.0000E+00 1.6094E+00 0.0000E+00 2.4428E+02 0.0000E+00
6 0.0000E+00 -5.0282E-01 0.0000E+00 6.0520E+00 0.0000E+00 7.8975E+01
*** OrcaFlex Added Mass Matrix End ***
1
-4.3- WAVE LENGTH NO.: 1
PAGE NO.: 2
WAVE LENGTH = 1.4052E+01
WAVE PERIOD = 3.0000E+00
---------------------------
DAMPING MATRIX
--------------
*** OrcaFlex Damping Matrix Start ***
Draught WadamDraught
WP 3
1 2 3 4 5 6
1 1.2500E-02 0.0000E+00 6.4335E-03 0.0000E+00 4.1028E-01 0.0000E+00
2 0.0000E+00 9.8425E-02 0.0000E+00 -1.7440E-02 0.0000E+00 1.5349E-01
3 1.3153E-02 0.0000E+00 3.5738E-02 0.0000E+00 9.9838E-01 0.0000E+00
4 0.0000E+00 1.3801E-02 0.0000E+00 6.3725E-01 0.0000E+00 4.0570E+00
5 4.9925E-01 0.0000E+00 7.9205E-01 0.0000E+00 2.9864E+01 0.0000E+00
6 0.0000E+00 4.2047E-01 0.0000E+00 3.6407E+00 0.0000E+00 4.2180E+01
*** OrcaFlex Damping Matrix End ***
[…]
-4.3- WAVE LENGTH NO.: 2
PAGE NO.: 1
+------------------------------------------------+
:+----------------------------------------------+:
:: ::
:: W A V E L E N G T H = 1.9126E+01 ::
:: ::
:: W A V E P E R I O D = 3.5000E+00 ::
:: ::
:: ::
:+----------------------------------------------+:
+------------------------------------------------+
ADDED MASS MATRIX
-----------------
*** OrcaFlex Added Mass Matrix Start ***
Draught WadamDraught
WP 3.5
1 2 3 4 5 6
1 2.5336E-02 0.0000E+00 5.0048E-02 0.0000E+00 1.6437E+00 0.0000E+00
2 0.0000E+00 1.5069E-01 0.0000E+00 -1.9495E-01 0.0000E+00 -6.1593E-01
3 4.5239E-02 0.0000E+00 1.0153E+00 0.0000E+00 1.4691E+00 0.0000E+00
4 0.0000E+00 1.1348E-01 0.0000E+00 7.0831E+00 0.0000E+00 6.3706E+00
5 1.6187E+00 0.0000E+00 1.7337E+00 0.0000E+00 2.3563E+02 0.0000E+00
6 0.0000E+00 -4.9195E-01 0.0000E+00 6.4953E+00 0.0000E+00 7.7202E+01
*** OrcaFlex Added Mass Matrix End ***
1
-4.3- WAVE LENGTH NO.: 2
PAGE NO.: 2
WAVE LENGTH = 1.9126E+01
WAVE PERIOD = 3.5000E+00
---------------------------
DAMPING MATRIX
--------------
*** OrcaFlex Damping Matrix Start ***
Draught WadamDraught
WP 3.5
1 2 3 4 5 6
1 1.4643E-02 0.0000E+00 8.3292E-03 0.0000E+00 5.1915E-01 0.0000E+00
2 0.0000E+00 5.9260E-02 0.0000E+00 -8.8822E-02 0.0000E+00 4.5559E-01
3 1.1167E-02 0.0000E+00 5.5467E-02 0.0000E+00 1.1583E+00 0.0000E+00
4 0.0000E+00 -3.5266E-02 0.0000E+00 6.6946E-01 0.0000E+00 4.4530E+00
5 5.4851E-01 0.0000E+00 1.0861E+00 0.0000E+00 3.5875E+01 0.0000E+00
6 0.0000E+00 5.6372E-01 0.0000E+00 4.4606E+00 0.0000E+00 5.0875E+01
*** OrcaFlex Damping Matrix End ***
[etc]