Morrisons Equation

[Don84]

Am using Morrisons Equation on a submerged device.

I have the formula for a pile in the sea floor and am modifying this by subtracting the force in the sections above and below the device.

The force disappears to zero as depth increases at 250 metres - which doesnt seem right.

I am wondering can anyone advise. Are there papers or articles with the specific formula for submerged devices?

Thanks for your help.

 

[Ussuri]

Forces determined by morrisons equation are dependent of velocity (Drag Force) and acceleration (Inertia Force).

Both of these will drop off as your depth increases. You will have a current as well though (tidal and surge) so you will never have zero at the seabed.

A couple of references:

Water Wave Mechanics for Engineers and Scientists by Dean and Dalrymple

Applied Offshore Structural Engineering by Hsu

Dynamics of Fixed Offshore Structres by Barltrop

Handbook of Offshore Engineering by Chakrabarti

 

[ozziz]

Ussuri

In a river current flow, it is only the drag coeffient and ignore the inertia term? But in the waves, the above 2 terms stand?

 

[BigInch]

I thought in deep water d>L/2, wave velocity is zero at the mud line and at that depth, you wouldn't have tide currents either, although possibly other currents might exist.

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