scientimate.wavebedstress#
Tau, Tauc, Tauw, Ust, z0 = scientimate.wavebedstress(h, heightfrombed, d50, Uc=0, H=0, T=0, Rho=1000, kCalcMethod='beji')
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 wavesHrms: root mean square wave height, Hrms=Hm0/sqrt(2)=Hs/sqrt(2)Hm0: zero moment wave height, Hs: significant wave heightset equal to 0 if not exist
- T=0
- Wave period in (s), T can be approximated and replaced by mean wave period for random wavesif peak wave frequency (Tp) is used, calculated values represent peak waveset 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 valueNote: 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#
import scientimate as sm
import numpy as np
Tau,Tauc,Tauw,Ust,z0=sm.wavebedstress(2,1.1,0.0000245,1.5,0.5,3,1000,'beji')
Tau,Tauc,Tauw,Ust,z0=sm.wavebedstress(2,1.1,0.0000245,[1.5,2],[0.5,0.6],[3,3.1],1000,'exact')
Tau,Tauc,Tauw,Ust,z0=sm.wavebedstress(2,1.1,0.0000245,np.array([1.5,2]),np.array([0.5,0.6]),np.array([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.