scientimate.mindurationdeep#
tmin, tminhat, Fetchhat = scientimate.mindurationdeep(windvel, Fetch, CalcMethod='carter', dispout='no')
Description#
Calculate a minimum required wind duration for wave to be fetch limited in deep water
Inputs#
- windvel
- Wind velocity in (m/s)Wind velocity should be measured (or represents velocity) at 10 m above surfaceWind velocity should be a 10 minutes averaged wind for all methods, except for for ‘cem’ and ‘spmdeep’ methodsFor ‘cem’ and ‘spmdeep’ methods, wind velocity should be converted to duration of sustained wind by using gust factor
- Fetch
Wind fetch in (m)
- CalcMethod=’carter’
- Parametric wave model to be used for calculation‘wilson’: Use method by Wislon (1965)‘jonswap’: Use method by Hasselmann et al. (1973) known as JONSWAP‘carter’: Use method by Carter (1982)‘spmdeep’: Use method by Shore Protection Manual (SPM),U.S. Army Corps of Engineers (1984) in deep water‘cem’: Use method by Coastal Engineering Manual (CEM),U.S. Army Corps of Engineers (2015)
- dispout=’no’
Define to display outputs or not (‘yes’: display, ‘no’: not display)
Outputs#
- tmin
Minimum required wind duration for wind to be fetch limited in (second)
- tminhat
Dimensionless minimum required wind duration for wind to be fetch limited: tminhat=g*tmin/U10
- Fetchhat
- Dimensionless Fetch: Fetchhat=g*Fetch/U10^2Note, g=9.81: gravitational accelerationU10: wind velocity
Examples#
import scientimate as sm
import numpy as np
windvel=10*np.random.rand(100)
Fetch=10000*np.random.rand(100)
tmin,tminhat,Fetchhat=sm.mindurationdeep(windvel,Fetch,'carter','no')
windvel=10
Fetch=np.arange(1e3,1e6,1000)
tmin,tminhat,Fetchhat=sm.mindurationdeep(windvel,Fetch,'carter','yes')
References#
Carter, D. J. T. (1982). Prediction of wave height and period for a constant wind velocity using the JONSWAP results. Ocean Engineering, 9(1), 17-33.
Department of the Army, Waterways Experiment Station, Corps of Engineers, and Coastal Engineering Research Center (1984), Shore Protection Manual, Washington, D.C., vol. 1, 4th ed., 532 pp.
Hasselmann, K.; Barnett, T. P.; Bouws, E.; Carlson, H.; Cartwright, D. E.; Enke, K.; Ewing, J. A.; Gienapp, H.; Hasselmann, D. E.; Kruseman, P.; Meerbrug, A.; Muller, P.; Olbers, D. J.; Richter, K.; Sell, W., and Walden, H., (1973). Measurements of wind-wave growth and swell decay during the Joint North Sea Wave Project (JONSWAP). Deutsche Hydrographische Zeitschrift A80(12), 95p.
U.S. Army Corps of Engineers (2015). Coastal Engineering Manual. Engineer Manual 1110-2-1100, Washington, D.C.: U.S. Army Corps of Engineers.
Wilson, B. W. (1965). Numerical prediction of ocean waves in the North Atlantic for December, 1959. Ocean Dynamics, 18(3), 114-130.