CMS-Flow:Wind Pressure: Difference between revisions

From CIRPwiki
Jump to navigation Jump to search
No edit summary
Line 3: Line 3:
In CMS-Flow the wind shear stress is calculated as
In CMS-Flow the wind shear stress is calculated as
       {{Equation| <math> \tau_{Wi} = \rho_a C_d |W| W_i </math> |2=1}}
       {{Equation| <math> \tau_{Wi} = \rho_a C_d |W| W_i </math> |2=1}}
where <math>W</math> is the 10-min average wind speed at a height of 10 m, <math>C_d</math> is the drag coefficient, and <math>\rho_a</math> is the atmospheric density (~1.2 kg/m^3).


The wind drag coefficient <math> C_d </math> is calculated using the Hsu (1988)
The wind drag coefficient <math> C_d </math> is calculated using the Hsu (1988)

Revision as of 17:17, 15 October 2010

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.



Documentation Portal