CMS-Flow:Ripple Dimensions: Difference between revisions

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m (Rdchlmeb moved page CMS-Flow: Ripple Dimensions to CMS-Flow:Ripple Dimensions: Getting rid of the space after the colon just to be consistent with other entries.)
 
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{{Equation|<math>
{{Equation|<math>
H_{r,w} = \left\{\begin{align}
H_{r,w} = \left\{\begin{align}
&0.22A_w \quad \quad for \ \psi_w < 10 \\
&0.22A_w \quad \quad\quad\quad\quad\quad\quad\quad\quad for \ \psi_w < 10 \\
&2.8 \ x\  10^{-13}(250 - \psi_w)^5 A_w \quad for \ 10 \quad \leq \psi_w <250 \\
&2.8 \ x\  10^{-13}(250 - \psi_w)^5 A_w \quad for \ 10 \ \leq \psi_w <250 \\
&0 \quad \quad \quad \quad \quad for \ 250 \leq \psi_w
&0 \quad \quad \quad \quad \quad\quad\quad\quad\quad\quad\quad\quad for \ 250 \leq \psi_w
\end{align} \right.</math>|4}}
\end{align} \right.</math>|4}}


{{Equation|<math>
{{Equation|<math>
L_{r,w} = \left\{\begin{align}
L_{r,w} = \left\{\begin{align}
&1.25 A_w \quad \quad for \ \psi_w < 10 \\
&1.25 A_w \quad \quad\quad\quad\quad\quad\quad\quad for \ \psi_w < 10 \\
&1.4 \ x \ 10^{-6}(250 - \psi_w)^{2.5} \quad for \ 10 \leq \psi_w < 250\\
&1.4 \ x \ 10^{-6}(250 - \psi_w)^{2.5} \quad for \ 10 \leq \psi_w < 250\\
&0 \quad \quad \quad \quad for \ 250 \leq \psi_w\end{align}
&0 \quad \quad \quad \quad\quad\quad\quad\quad\quad\quad for \ 250 \leq \psi_w\end{align}
\right.</math>|5}}
\right.</math>|5}}


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:d<sub>50</sub> = median grain size [m]
:d<sub>50</sub> = median grain size [m]


:s sediment specific gravity [-]
:s = sediment specific gravity [-]


:g = gravitational constant (9.81 m/s<sup>2</sup>)
:g = gravitational constant (9.81 m/s<sup>2</sup>)


:u<sub>w</sub> = bottom orbital velocity [m/s] (for random waves u<sub>w</sub> = <math>\sqrt{2} u_{rms})</math>
:u<sub>w</sub> = bottom orbital velocity [m/s] (for random waves <math>u_w = \sqrt{2} u_{rms})</math>


:T = wave period [s] (for random waves T = T<sub>p</sub>).
:T = wave period [s] (for random waves T = T<sub>p</sub>).
Line 43: Line 43:


= References =
= References =
*Soulsby, R. L. 1997. Dynamics of marine sands. London, England: Thomas Telford Publications.
*van Rijn, L. C. 1984b. Sediment transport, Part II: Suspended-load transport. Journal of Hydraulic Engineering, ASCE 110(11):1613–1641.
*van Rijn, L. C. 1989. Handbook: Sediment transport by currents and waves. Delft, The Netherlands: Delft Hydraulics.


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[[CMS#Documentation_Portal | Documentation Portal]]
[[CMS#Documentation_Portal | Documentation Portal]]

Latest revision as of 15:34, 23 January 2023

The bed forms calculated by CMS are the wave- and current-related ripples. The ripple height (used to calculate the mixing layer thickness) is estimated as the maximum of the current- and wave-related ripple heights

  (1)

The current-related ripple height and length are calculated as (Soulsby 1997)

  (2)
  (3)

The wave-related ripple height and length are calculated using the expressions proposed by van Rijn (1984b, 1989):

  (4)
  (5)

where:

Aw = semi-orbital excurision =
= wave mobility parameter =
d50 = median grain size [m]
s = sediment specific gravity [-]
g = gravitational constant (9.81 m/s2)
uw = bottom orbital velocity [m/s] (for random waves
T = wave period [s] (for random waves T = Tp).

The current- and wave-related ripple height and length are used in calculating the bed form roughness for use in the Lund-CIRP transport formula.

References

  • Soulsby, R. L. 1997. Dynamics of marine sands. London, England: Thomas Telford Publications.
  • van Rijn, L. C. 1984b. Sediment transport, Part II: Suspended-load transport. Journal of Hydraulic Engineering, ASCE 110(11):1613–1641.
  • van Rijn, L. C. 1989. Handbook: Sediment transport by currents and waves. Delft, The Netherlands: Delft Hydraulics.

Documentation Portal