How to create scatter data using the Metocean task


Main steps

  • Scatter data is generated using the metocean task

    • Set up the the type of scatter data

    • Specify the scatter data calculation

    • Make a and run the condition


Generate a metocean task

Right click and choose new

  • Metocean Task

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  • Give the metocean task a name

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Choose Scatter Data

  • Choose the type of scatter data you want to model

    1. Omnidirectional Scatter Data

    2. Direction dependent Scatter Data

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Example: Choose omnidirectional data

  • Specify the input in the cells

    • Start values for significant wave height, Hs, and peak period, Tp

    • Stepping (=Delta)

    • Number of values you want

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  • Add data to the cells

    • This can be entered manually

    • or imported from the clipboard

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Enter data

  • Import from clipboard

  • If you have the data in excel, you may copy these cell and choose Import from clipboard Add data to the cells

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  • Enter data by typing in the cells

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Scatter data calculation

  • Set up scatter data calculation by right click New

    • Choose Scatter Data Calculation

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  • In the Scatter Data Calculation

    • Choose the Scatter Data: omni

    • Set wave directions: 0 deg

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Make a condition

  • Make a new metocean condition

  • Give it a name MyCondition

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  • In the condition

    • Choose ScatterDataCalculation in the drop down list

    • Run by clicking on the green icon

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Study the results

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Relation between the sea states and selected wind and current data

Procedure

  • For each sea state, \(H_{s}\),\(T_{p}\) and \(\theta_{}\)

    • for all wind speed levels

      • interpolate to find wind speed and direction using \(H_{s}\) and \(T_{p}\)

    • for all current speed levels

      • interpolate to find current speed and direction using \(H_{s}\) and \(T_{p}\)


Use of profiles to find the current speed

The current levels for different water depth can be calculated using the option From wind velocity for Scatter Data and Hind Cast Calculation.

The current speed is estimated using the wind speed in a given Wind reference level combined with two profile.

  • Wind Current Profile, \(f_{w2c}(z)\)

  • Base Current Profile, \(f_{cbase}(z)\)

    • The Base Current Profile is multiplied with the Base Current Speed, \(u_{mean}\)

\[U_{current}(Z)=u_{wind}(z_{ref})\cdot f_{w2c}(z) + u_{mean}\cdot f_{cbase}(z)\]

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