CMS-Flow:Wind Pressure: Difference between revisions

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== Pressure ==
== Pressure ==
The atmospheric pressure is included in the momentum equations as an additional pressure gradient term
The atmospheric pressure is included in the momentum equations as an additional pressure gradient term
\begin{equation} \tag{4} \frac{h}{\rho_0} \frac{\partial p_a }{\partial x_j} \end{equation}
{{Equation|<math>\frac{h}{\rho_0} \frac{\partial p_a }{\partial x_j}</math>|4}}


== Symbol Index ==
== Symbol Index ==

Revision as of 14:59, 22 October 2012

Wind

In CMS-Flow the wind shear stress is calculated as

  (1)

where is the 10-min average wind speed at a height of 10 m, is the drag coefficient, and is the atmospheric density (~1.2 kg/m^3).

The wind drag coefficient is calculated using the Hsu (1988)

  (2)

For measurements of wind speed made at heights other than 10 m, an approximation of the 10-m wind speed is (Shore Protection Manual 1984)

  (3)

Pressure

The atmospheric pressure is included in the momentum equations as an additional pressure gradient term

  (4)

Symbol Index

Symbol Description Units
Wind shear stress Pa
Atmospheric density (~1.2 kg/m^3) kg/m^3
Wind drag coefficient none
10-min averaged wind speed at 10 m above the sea surface m/sec
Wind direction m/sec


References

  • Hsu, S.A. (1988) Coastal meteorology. Academic Press, San Diego, CA.
  • Shore Protection Manual (1984) 4th ed., 2nd Vol, U.S. Army Engineer Waterways Experiment Station, U.S. Government Printing Office, Washington, DC.



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