Added resistance in waves: Response Amplitude Operator (calculation)


How it works
When sailing against waves, a sailing craft experiences an additional resistance that penalizes its performance. To study how the boat is affected, one of the methods developed requires both a statistical model of the sea’s surface the yacht is sailing in (usually through the wave spectral density) and the Response Amplitude Operator (RAO) of the yacht (yacht’s response to waves of different amplitudes and frequencies).
This calculation estimates the RAO (Response Amplitude Operator) of an arbitrary yacht. The calculation needs basic hull data such as LWL, TC, BWL, ∇C, and CP and the value of the density of the water (default is 1026 kg/m3). The latter is necessary for transforming the non-dimensional RAO into a dimensional one.
The results are calculated for the combination of different values of the longitudinal radius of gyration, Froude number, and wave directions:


See also:
- Added resistance in waves of a yacht (calculation).
- Added resistance in waves knowing yacht’s radius of gyration (calculation).
- What the hydrodynamic resistance is and why it matters.
- Sea state and wave forecasting.
- Surface waves.
- Introducing the hull.
References:
Some of the links shown below are affiliate links and we may earn a commission at no additional cost to you:
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Claughton A. R., Wellicome J. F., Shenoi, R. A. (2006). Sailing Yacht Design: Theory
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Larsson, L., Eliasson, R.E, Orych, M. (2014). Principles of Yacht Design
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Fossati, F. (2009). Aero-Hydrodynamics and the Performance of Sailing Yachts
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Slooff, J. (2018). The Science behind Sailing
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