virocon.predefined module

Common joint model structure are predefined in this module.

virocon.predefined.get_DNVGL_Hs_Tz()

Get DNVGL significant wave height and wave period model.

Get the descriptions necessary to create th significant wave height and wave period model as defined in DNVGL [1] in section 3.6.3.

Returns:

• dist_descriptions (list of dict) – List of dictionaries containing the dist descriptions for each dimension. Can be used to create a GlobalHierarchicalModel.

• fit_descriptions (None) – Default fit is used so None is returned. Can be passed to fit function of GlobalHierarchicalModel.

• semantics (dict) – Dictionary with a semantic description of the model. Can be passed to plot functions.

References

[1]

DNV GL (2017). Recommended practice DNVGL-RP-C205: Environmental conditions and environmental loads.

virocon.predefined.get_DNVGL_Hs_U()

Get DNVGL significant wave height and wind speed model.

Get the descriptions necessary to create the significant wave height and wind speed model as defined in DNVGL [2] in section 3.6.4.

Returns:

• dist_descriptions (list of dict) – List of dictionaries containing the dist descriptions for each dimension. Can be used to create a GlobalHierarchicalModel.

• fit_descriptions (None) – Default fit is used so None is returned. Can be passed to fit function of GlobalHierarchicalModel.

• semantics (dict) – Dictionary with a semantic description of the model. Can be passed to plot functions.

References

[2]

DNV GL (2017). Recommended practice DNVGL-RP-C205: Environmental conditions and environmental loads.

virocon.predefined.get_Nonzero_EW_Hs_S()

Get the non-zero EW sea state model.

Get the descriptions necessary to create the significant wave height - steepness model that is an adaptation of Windmeier’s EW model [5]_. Both, Hs and Steepness follow an exponentiated Weibull distribution.

Compared to Windmeier’s EW model, this model has a dependence function for scale that evaluates to scale > 0 at hs = 0 m . The dependence function reads: shift + a * (1 - np.exp(-b * hs))

Because the model is defined in Hs-steepness space it must be transformed to Hs-Tz for contour calculation.

This model was introduced in the virocon software, there is research paper describing it.

Returns:

• dist_descriptions (list of dict) – List of dictionaries containing the dist descriptions for each dimension. Can be used to create a GlobalHierarchicalModel.

• fit_descriptions (None) – Default fit is used so None is returned. Can be passed to fit function of GlobalHierarchicalModel.

• semantics (dict) – Dictionary with a semantic description of the model. Can be passed to plot functions.

• transformations (dict)

References

[5]

Windmeier, K.-L. (2022). Modeling the statistical distribution of sea state

parameters [Master Thesis, University of Bremen]. https://doi.org/10.26092/elib/2181

virocon.predefined.get_OMAE2020_Hs_Tz()

Get OMAE2020 significant wave height and wave period model.

Get the descriptions necessary to create the significant wave height and wave period model as described by Haselsteiner et al. [3].

Returns:

• dist_descriptions (list of dict) – List of dictionaries containing the dist descriptions for each dimension. Can be used to create a GlobalHierarchicalModel.

• fit_descriptions (list of dict) – List of dictionaries containing the fit description for each dimension. Can be passed to fit function of GlobalHierarchicalModel.

• semantics (dict) – Dictionary with a semantic description of the model. Can be passed to plot functions.

References

[3]

Haselsteiner, A.F.; Sander, A.; Ohlendorf, J.H.; Thoben, K.D. (2020) Global hierarchical models for wind and wave contours: Physical interpretations of the dependence functions. OMAE 2020, Fort Lauderdale, USA. Proceedings of the 39th International Conference on Ocean, Offshore and Arctic Engineering.

virocon.predefined.get_OMAE2020_V_Hs()

Get OMAE2020 wind speed and significant wave height model.

Get the descriptions necessary to create the wind speed and significant wave height model as described by Haselsteiner et al. [4].

Returns:

• dist_descriptions (list of dict) – List of dictionaries containing the dist descriptions for each dimension. Can be used to create a GlobalHierarchicalModel.

• fit_descriptions (list of dict) – List of dictionaries containing the fit description for each dimension. Can be passed to fit function of GlobalHierarchicalModel.

• semantics (dict) – Dictionary with a semantic description of the model. Can be passed to plot functions.

References

[4]

Haselsteiner, A.F.; Sander, A.; Ohlendorf, J.H.; Thoben, K.D. (2020) Global hierarchical models for wind and wave contours: Physical interpretations of the dependence functions. OMAE 2020, Fort Lauderdale, USA. Proceedings of the 39th International Conference on Ocean, Offshore and Arctic Engineering.

virocon.predefined.get_Windmeier_EW_Hs_S()

Get Windmeier’s EW sea state model.

Get the descriptions necessary to create the significant wave height - steepness model that was proposed by Windmeier [5]_. Both, Hs and Steepness follow an exponentiated Weibull distribution.

Because the model is defined in Hs-steepness space it must be transformed to Hs-Tz for contour calculation.

Returns:

• dist_descriptions (list of dict) – List of dictionaries containing the dist descriptions for each dimension. Can be used to create a GlobalHierarchicalModel.

• fit_descriptions (None) – Default fit is used so None is returned. Can be passed to fit function of GlobalHierarchicalModel.

• semantics (dict) – Dictionary with a semantic description of the model. Can be passed to plot functions.

• transformations (dict)

References

[5]

Windmeier, K.-L. (2022). Modeling the statistical distribution of sea state

parameters [Master Thesis, University of Bremen]. https://doi.org/10.26092/elib/2181