# “Calculate the wind load in the direction of the incoming wind from 0° to 180° with an angle of 30°

Discussion in 'Hydrodynamics and Aerodynamics' started by sun, Nov 3, 2021.

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### sunJunior Member

When calculating the action of wind or waves in different directions on offshore structures, why only calculate the "0°～180° load in the direction of the incoming wind or waves"? Why are all "30° angles as an interval"?

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### gonzoSenior Member

The maximum force is the only value of interest. That is what the design loads are.

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### sunJunior Member

I want to calculate the force on a structure. How to choose wind direction or wave direction？ （10°、20°、30°......360°）？

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### CT 249Senior Member

What force and why?

As Gonzo implies, this is not a simple question.

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### sunJunior Member

A new marine structure.

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### gonzoSenior Member

Unless you are one of the sea gods, you don't get to choose the direction/force of the wind and waves. You need to use observed values for your location.

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### TANSLSenior Member

As in many other calculations, it is difficult to know a priori which is the worst circumstance. One must calculate several options to know which is the worst condition among the several possible ones.

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### wet feetSenior Member

Surely you ought to calculate the loads that may be imposed from any direction.Failing to include all scenarios would be negligent.

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### sunJunior Member

Thank you everyone for your valuable feedback.

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yes all the forces can be calculated, the offshore industry does it all the time.
Sometimes from wind tunnel data if availible
The Dynamic Positioning industry is required to do this on Dp vessels.
You get printed tables from the DP supplier and the data is used in the DP software.
You do front area and then beam area, wind calc at 10metre level std air density and then there are formulas to do the other angles.

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