wavebedstress#

[Tau, Tauc, Tauw, Ust, z0] = wavebedstress(h, heightfrombed, d50, Uc, H, T, Rho, kCalcMethod)

Description#

Calculate the bottom shear velocity and shear stress from current velocity and wave

Inputs#

h

Water depth in (m)

heightfrombed

Sensor height from bed in (m)

d50

Median bed particle diameter in (m)

Uc=0;

Current velocity at sensor height in (m/s), set equal to 0 if not exist

H=0;
Wave height in (m), H can be approximated and replaced by Hrms for random waves
Hrms: root mean square wave height, Hrms=Hm0/sqrt(2)=Hs/sqrt(2)
Hm0: zero moment wave height, Hs: significant wave height
set equal to 0 if not exist
T=0;
Wave period in (s), T can be approximated and replaced by mean wave period for random waves
if peak wave frequency (Tp) is used, calculated values represent peak wave
set equal to 0 if not exist
Rho=1000;

Water density in (kg/m^3)

kCalcMethod=’beji’;
Wave number calculation method
‘hunt’: Hunt (1979), ‘beji’: Beji (2013), ‘vatankhah’: Vatankhah and Aghashariatmadari (2013)
‘goda’: Goda (2010), ‘exact’: calculate exact value
Note: inputs can be as a single value or a 1-D vertical array

Outputs#

Tau

Total bottom shear stress from current velocity and wave

Tauc

Bottom shear stress from current velocity

Tauw

Bottom shear stress from wave

Ust

Bottom shear velocity (m/s)

z0

Surface roughness in (N/m^2)

Examples#

[Tau,Tauc,Tauw,Ust,z0]=wavebedstress(2,1.1,0.0000245,1.5,0.5,3,1000,'beji');

[Tau,Tauc,Tauw,Ust,z0]=wavebedstress(2,1.1,0.0000245,[1.5;2],[0.5;0.6],[3;3.1],1000,'exact');

References#

Beji, S. (2013). Improved explicit approximation of linear dispersion relationship for gravity waves. Coastal Engineering, 73, 11-12.

Goda, Y. (2010). Random seas and design of maritime structures. World scientific.

Hunt, J. N. (1979). Direct solution of wave dispersion equation. Journal of the Waterway Port Coastal and Ocean Division, 105(4), 457-459.

Vatankhah, A. R., & Aghashariatmadari, Z. (2013). Improved explicit approximation of linear dispersion relationship for gravity waves: A discussion. Coastal engineering, 78, 21-22.