Python reference: OrcaFlexVesselObject

The class OrcaFlexVesselObject is the Python interface representation of an OrcaFlex vessel. This class subclasses OrcaFlexObject so offers the same attributes and methods, with the addition of vessel specific methods described here.

Construction

A new OrcaFlexVesselObject is created from a Model object like this:

model = OrcFxAPI.Model()

vessel = model.CreateObject(OrcFxAPI.ObjectType.Vessel, "vessel2") # Create a new vessel object called "vessel2"

Or, where the OrcaFlex vessel already exists, like this:

vessel = model["vessel2"]

Attributes and methods

SaveDisplacementRAOsSpreadsheet, SaveSpectralResponseSpreadsheet

vessel.SaveDisplacementRAOsSpreadsheet(filename)

vessel.SaveSpectralResponseSpreadsheet(filename)

Saves displacement RAO or spectral response reports to filename. The file can be an Excel spreadsheet (.xlsx or .xls), a tab delimited file (.txt) or a comma separated file (.csv). The decision is taken based on the file extension that you specify. This method is implemented by calling C_SaveSpreadsheet.

SaveDisplacementRAOsSpreadsheetMem, SaveSpectralResponseSpreadsheetMem

vessel.SaveDisplacementRAOsSpreadsheetMem(spreadsheetFileType=SpreadsheetFileType.Xlsx)

vessel.SaveSpectralResponseSpreadsheetMem(spreadsheetFileType=SpreadsheetFileType.Xlsx)

Saves displacement RAO or spectral response reports, returning them as a bytearray object. The spreadsheetFileType parameter can be either SpreadsheetFileType.Csv, SpreadsheetFileType.Tab or SpreadsheetFileType.Xlsx to specify the spreadsheet format. This method is implemented by calling C_SaveSpreadsheetMem.

SaveSupportGeometryTable

vessel.SaveSupportGeometryTable(filename)

Saves the support geometry report to filename. The file can be an Excel spreadsheet (.xlsx or .xls), a tab delimited file (.txt) or a comma separated file (.csv). The decision is taken based on the file extension that you specify. This method is implemented by calling C_SaveSpreadsheet.

SaveSupportGeometryTableMem

vessel.SaveSupportGeometryTableMem(spreadsheetFileType=SpreadsheetFileType.Xlsx)

Saves the support geometry report, returning it as a bytearray object. The spreadsheetFileType parameter can be either SpreadsheetFileType.Csv, SpreadsheetFileType.Tab or SpreadsheetFileType.Xlsx to specify the spreadsheet format. This method is implemented by calling C_SaveSpreadsheetMem.

SaveAirGapReport

vessel.SaveAirGapReport(filename, period=None)

Saves the air gap report spreadsheet for the specified period to filename. If period is set to None or omitted then the whole simulation period is used. The file can be an Excel spreadsheet (.xlsx or .xls), a tab delimited file (.txt) or a comma separated file (.csv). The decision is taken based on the file extension that you specify. This method is implemented by calling C_SaveSpreadsheet.

SaveAirGapReportMem

vessel.SaveAirGapReportMem(spreadsheetFileType=SpreadsheetFileType.Xlsx, period=None)

Saves the air gap report spreadsheet for the specified period, returning it as a bytearray object. If period is set to None or omitted then the whole simulation period is used. The spreadsheetFileType parameter can be either SpreadsheetFileType.Csv, SpreadsheetFileType.Tab or SpreadsheetFileType.Xlsx to specify the spreadsheet format. This method is implemented by calling C_SaveSpreadsheetMem.

AirGapPointsSpecifications

vessel.AirGapPointsSpecifications

Returns an iterable of time history specifications corresponding to the user-defined air gap reporting point data for the vessel. These specifications can be passed to GetMultipleTimeHistories

PanelPressureTimeHistory

PanelPressureTimeHistory(diffraction, resultPanels, period=None, parameters=None)

Calculates time domain panel pressure results for this vessel. This method is implemented by calling C_GetPanelPressureTimeHistory.

The vessel must belong to a time domain OrcaFlex model. The OrcaFlex simulation must be complete – you can call RunSimulation to perform the simulation or call LoadSimulation to open an existing results file.

diffraction is a Diffraction object of an OrcaWave model that includes the same vessel. The diffraction object must represent a completed calculation – you can call the Calculate method to perform the calculation or call LoadResults to open an existing results file. The diffraction object must include the output option for intermediate results.

resultPanels is an iterable of 0-based indices specifying the panels for which pressure time history is to be calculated:

Each index must be in the range 0 to PanelCount-1 inclusive, where PanelCount is the number of panels for which OrcaWave panel results are available. PanelCount can be obtained from the length of the panelGeometry attribute of diffraction.
Each index must specify a panel that belongs to this vessel. If diffraction contains more than one body, or a damping lid, you may need to identify the owner of each panel. Do this using the ObjectId member of the TDiffractionPanelGeometry structure.

period is a Period object that specifies the period of the simulation over which results are to be calculated. If period is omitted then the default value is Period(PeriodNum.WholeSimulation).

parameters is a PanelPressureParameters object that specifies the components of water pressure to be included in the panel pressure calculation. If parameters is omitted then the default value is PanelPressureParameters(True, True, True).

If you include the diffraction component of panel pressure, the following requirement applies:

The calculation will include a non-zero contribution only if wave load (1^st order) is in the vessel's included effects.

If you include the radiation component of panel pressure, the following requirements apply:

The calculation will include a non-zero contribution only if added mass and damping is in the vessel's included effects.
The logging sample interval must equal the appropriate time step, i.e. the implicit integration time step or the explicit integration outer time step.
If the vessel belongs to a multibody group, the multibody group must include all the diffraction bodies from the OrcaWave model and in the same order.
If the OrcaWave model is multibody but you wish to neglect multibody effects in the OrcaFlex simulation, you must remove the vessel from its multibody group before running the simulation.

Tip:	Calculating the radiation component is particularly expensive. Use the threadCount property to set the number of processing threads, in order to calculate pressure results in parallel for different panels. Use the progressHandler property to set up a handler for progress notifications.

This method returns a numpy array with shape [N_t, N_rp], where N_t is the number of samples in the specified period and N_rp is the number of resultPanels.