(L) Instructs Aqwa-Line to print the hydrodynamic database (the .HYD file) in a compact ASCII format to a new file with a .AH1 extension. If the option AHD? is ALSO used, a file will be printed that explains the format.

(L) When used with the AHD1 option, instructs Aqwa-Line to print a sample of the .AH1 file, with annotation to explain the format.

(L) The AQTF run-time option for Aqwa-Line will output an ASCII file AL*.QTF which can be used for external postprocessing. A description of the file format may be found in The CQTF Data Record - Import of QTF Database. Details of how Aqwa computes the QTF matrices can be found in General QTF Coefficient Matrix in Multiple Directional Waves in the Aqwa Theory Manual.

(DN) Instructs Aqwa-Drift or Naut to use the convolution method in the radiation force calculation. This is a more rigorous approach to the radiation force calculation in the time domain and will enhance the capability of handling a non-linear response of structures. This method is used by default but can be turned off using NCNV.

(L) The CQTF run-time option for Aqwa-Line requests calculation of the full QTF matrix. Note that this option does not give printed output; the AQTF option is needed to obtain this.

(F) Instructs Aqwa-Fer to calculate and output the RAOs for each structure, INCLUDING the mooring lines, but assuming each body is independently moving. These may be used to assess the effect of the coupling of the complete system by comparing these RAOs with those for the fully coupled system (see PRRI). This is done for the first spectrum of each mooring line combination only, unless the PRRP option is used.

(BDFLN) This option may be used with Aqwa-Line but is more useful with the program Aqwa-Fer. This option instigates the calculation of RAOs using the values of added mass, wave damping, stiffness and wave forcing specified by the user. The RAOs are then written into the database.

(BDFLN) This option is used to check the data input to the program and provides a means by which the user may check all input data whilst incurring minimum cost of the program run. This option is equivalent to performing the analysis up to the end of the second stage in Aqwa-Line, and up to the end of Stage 4 in Aqwa-Drift/Fer/Librium/Naut. If the data proved to be correct, then the program would be restarted at next stage of the analysis by using the RESTART option.

This is used to indicate the end of the option list.

(DN) This option instructs the program to call a routine called "user_force" at each stage of the calculation. This routine can be used to add externally calculated forces to the simulation.

(N) This option switches on the printing of the *.ADM file which contains the fluid added mass matrix at the infinite frequency.

(FD) This option specifies that the full matrix of difference frequency QTFs is to be used when calculating slowly varying drift forces. See also SQTF.

(F) This option switches the axis system in Aqwa-Fer output into the global system.

(L) This option allows the analysis to go on in spite of the modeling rule violations. Most of the modeling errors will be turned into warnings by this option. Users are advised not to use this option unless the violations are minor and difficult to correct. For more information on modeling rules, see Mesh Quality Check in the Aqwa Theory Manual.

(BFDN) This option is used to output articulation reaction forces in the local articulation axis system. This means that the moments in unconstrained freedoms, e.g. the hinge axis, will always be zero within roundoff. Note that for fixed articulations or ball-joints the local axes are parallel to the FRA.

(L) This option is used in Aqwa-Line to output RAOs, including linearized Morison drag, on all TUBE and DISC elements. It is only available for a single spectrum which must be defined in Data Category 13. Although multiple structures can be analyzed they must not be connected by an additional structural stiffness matrix, articulations, or moorings. The run must include stage 5. Morison element linearization is not available when forward speed is defined.

(F) This option is used in Aqwa-Fer to include linearized drag in the calculations. Linearized drag includes:

Unlike Aqwa-Line, it is available for multiple spectra. Multiple structures can be analyzed with any combination of connections provided by Aqwa.

(L) This option is used in Aqwa-Line to calculate the first order hydrodynamic properties at low and high wave frequencies. The low wave frequency corresponds to the encounter frequency of rad/s, where g = acceleration due to gravity and d = water depth. The high wave frequency corresponds to the absolute value of the encounter frequency, i.e. 100 rad/s.

This option is automatically turned on if the full QTF option CQTF is used.

(N) This is used to start a simulation with the motions and velocities derived from the Aqwa-Line results. This can be used to limit the transient at the start of a simulation.

(BFDN) This option is used to output articulation reaction force in the local structural axis system. This means that the direction of the output reaction force will follow the structure.

(BN) This option should be used when the user wishes to use the linear stiffness matrix (calculated by Aqwa-Line or input in Data Category 7) as opposed to the program recalculating the hydrostatic stiffness from the hydrostatic element model. This normally will reduce the time to run the program substantially.

(DN) From version 5.3K onward the default method for calculation of the Convolution Integral Function uses the radiation damping only. This option forces the program to use the previous method based on both added mass and damping.

(N) The MNVR run-time option for Aqwa-Naut requests calculation of low frequency maneuvering loads.

(L) The MQTF run-time option for Aqwa-Line requests calculation of QTF coefficients including interaction between different wave directions. This will result in output of a new binary file with a .MQT extension. This can be utilized in a subsequent Aqwa-Librium. Aqwa-Fer, or Aqwa-Drift analysis using the FILE and CSTR data records in the Drift Motion Parameters data category.

(DN) This option instructs Aqwa-Drift or Naut to calculate motions using RAOs only. These may be defined by the user in Deck7. Note that this option suppresses all motion except that defined by the RAOs. In particular current, wind, drift forces, moorings etc. have no effect on the motions of the structure.

(LBFDN) This option will cause any additional structural stiffness, whether in the database or input in Data Category 7, to be ignored. Its purpose is to allow an Aqwa-Line run including additional stiffness to be followed by stages 3 - 6 in another module which may include moorings with an equivalent stiffness.

(DN) This option switches off the convolution method (CONV) in AQWA-Drift/NAUT. In AQWA DRIFT and NAUT, the convolution method is set as default for the radiation force calculation. This option forces AQWA-Drift to use the RAO based radiation method instead of the convolution method, or forces AQWA-Naut in the regular wave case to include the added mass and damping matrices at the defined regular wave period in the equation of motion.

(L) This option will cause Aqwa-Line to use the old method (pre 5.5D) for integration of the Green's Function. It has been added for compatibility with previous versions.

(ND) This option switches off the wave phase shift due to a current speed.

(BDFN) This option switches off all extended data output in the .LIS file.

(L) This option flags the program not to perform the Mean Wave Drift Force calculations.

(L) This is to switch off the output of field point wave elevation in the .LIS file.

(LFDN) This option stops the progress window being displayed.

(L) This option stops the merging of hydrodynamic databases and re-calculation of QTFs. It is required if a .HYD file is imported (into Aqwa-Line only) but the .PAC and .VAC files are not available.

(D) This option stops the automatic calculation of statistics at the end of each simulation run. Statistical processing can be lengthy for long simulations. This option can be used to reduce processing time if statistics are not required.

(D) This option stops the automatic calculation of wave drift damping for a floating structure in Aqwa-Drift. When this option is used, the wave drift damping should be defined in data category 9. Note that the wave drift damping calculated by the program is only for the floating structure defined in Aqwa-Line, damping from risers, etc is not included. The NYWD option stops calculation of wave drift damping for yaw motion only.

(L) This option tells the program that there will be no pressure post-processing and therefore the connectivity warnings can be omitted.

(L) This option invokes Aqwa-Line to use the near field solution in the calculation of mean drift force. By default the far field solution is used which only calculates the mean drift force in three horizontal degrees of freedom (i.e. surge, sway and yaw). The far field solution is also unable to consider the hydrodynamic interaction between structures or a structure with forward speed.

(L) This option is used to output in Aqwa-Line run RAOs at particular nodes defined in Data Category 18. The run stages should be from 1 to 5.

(N) This option suppresses the LFP reproduction of irregular waves from the import wave height time history record. The JONSWAP fit of the wave spectrum will be used. This reproduces the approach used in Aqwa-Naut before the introduction of the LFP methodology.

(D) This option suppresses the calculation of wave drift damping for yaw motion. To prevent the calculation of ALL wave drift damping use the NOWD option.

(L) This option is used in conjunction with field point data records FPNT in Data Category 2 to output free surface elevation at specified field points.

(BDFLN) This option switches on printing of the old lineprinter-style banner page in the .LIS file.

(N) This option switches on the co-simulation mechanism for the Aqwa-Naut analysis.

(BDFN) Read the hydrodynamics database from the restart (.RES) file created by a previous Aqwa-Line run.

This option is used if the user wishes to modify the hydrodynamic data calculated in a previous Aqwa-Line run, without having to re-run the Aqwa-Line radiation/diffraction analysis.

(BFDN) This option can be used in Librium, Fer, Drift and Naut to read in the structures equilibrium position from a previous Librium run as the start position. An AB*.EQP file should be copied to AF*.EQP before a Fer run, to AD*.EQP before a Drift run or to AN*.EQP before a Naut run. The .EQP file will be copied automatically if the file root is entered on the RESTART data record.

(ALL) This option is used when the program is being restarted at any stage greater than the first (see Analysis Stages). A restart data record must follow the options list when the restart option is used This data record indicates the stage at which the program is to continue and the stage at which the program is to stop.

(Switched by SC1/Data Record)

(BDN) Together with the SC1/ data record in Data Category 17 this option causes drag coefficients to be calculated using the Wieselburger curve for Reynold's number dependent drag coefficients. Drag coefficients in Data Category 4 (including defaults) are set to zero.

(D) This option is used if users wish to use the slow velocity (drift frequency velocity) for the hull drag calculation, instead of the total velocity (drift frequency velocity + wave frequency velocity) which is the default.

(L) This option instructs Aqwa-Line to calculate shear forces and bending moments in Stage 5. A .SHB file is produced which can be read by the AGS.

(D) This option specifies that the full matrix of sum frequency QTFs is to be used when calculating slowly varying drift forces. Note that this option also sets the FQTF option. It is not possible to perform an analysis using only the sum QTFs.

(DN) This option instructs the program to look for an external server for calculating user-defined forces. For more information, see External Server for User-Defined Force Calculation.

(DN) This option switches off the slow axis system and stops printout of harmonic analysis at the end of a simulation run. This option should not in general be used. It is only provided as a workround for Drift analysis for both drift and wave frequency motions if it diverges in the time integration.

(D) When this option is used Aqwa-Drift will re-calculate the forces based on the RAOs, which can be input by the user in Data Category 7. This allows RAOs obtained from tank tests (for example) to be used with the CONV option in transient analyses. If the RAOs are not modified this option has little effect.

(L) This option instructs Aqwa-Line to update the hydrodynamic databases (.PAC and .VAC files), and to recalculate QTFs based on the RAOs input by the user in Data Category 7. It is required that a .HYD file is imported (into Aqwa-Line only) and the .PAC and .VAC files are available.

The option is ignored when the NOMG option is set.

(N) This option specifies that Wheeler stretching should be used in Aqwa-Naut when calculating the Froude-Krylov force based on the instantaneous wave surface.