# shallow water VS deep water

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 August 26, 2004, 10:33 shallow water VS deep water #1 Paul Guest   Posts: n/a Is there any rigorous definition of shallow water and deep water in terms of depth of the water? thanks!

 August 26, 2004, 11:33 Re: shallow water VS deep water #2 Jon Guest   Posts: n/a Depends how tall you are.

 August 26, 2004, 11:36 Re: shallow water VS deep water #3 Paul Guest   Posts: n/a interesting argument. I mean the explorsion in the shallow water or the deep water.

 August 26, 2004, 11:36 Re: shallow water VS deep water #4 Jarmo Monttinen Guest   Posts: n/a Seem to recall that this would have to do something with the waves... try these links: http://www.google.com/search?hl=en&l...TF-8&q=shallow+water+approximation -- Jarmo

 August 27, 2004, 04:24 Re: shallow water VS deep water #5 Tom Guest   Posts: n/a As Jarmo points out it is defined in terms of waves. Specifically for a layer of fluid of depth H the dispersion relation linking the frequency and wavenumber is (in the absense of surface tension) w = sqrt( g.k.tanh(kH) ) where g is the acceleration due to gravity. For deep water, where kH >> 1, w ~ sqrt(gk) and the depth of the layer is much greater than the length of the surface waves which propagate on it. For shallow water the surface waves are much longer than the depth of the layer so that kH << 1 and w ~ sqrt(gH)k (which are non dispersive), Tom.

 August 27, 2004, 05:20 Re: shallow water VS deep water #6 Kel Guest   Posts: n/a Tom, that means the symbol "k" in your formula?

 August 27, 2004, 07:19 Re: shallow water VS deep water #7 Tom Guest   Posts: n/a It's the wavenumber = 2.pi/wavelength

 August 27, 2004, 15:56 Re: shallow water VS deep water #8 Wen Long Guest   Posts: n/a Shallow water approximation or deep water approximation are two ends of asymptotic approximation in water wave theory. For shallow water, when h/L is less than 1/20, it's called shallow water, when 1/20 1/2 it's called deep water. where h is depth, L is wave length(distance between to adjecent wave crests) for ocean, say h=1000m, if wave length > 20 km is still called shallow water though 1000m is not that shallow at all. For commonly seeng waves with L =10m, h <10/20=0.5m is called shallow water, h>10/2=5m is called deep water. We see that shallow water is really shallow, and deep water is not horriblely deep.

 August 27, 2004, 15:58 Re: shallow water VS deep water #9 Wen Long Guest   Posts: n/a Shallow water approximation or deep water approximation are two ends of asymptotic approximation in water wave theory. For shallow water, when h/L is less than 1/20, it's called shallow water, when h/L larger than 1/20 but less than 1/2, it's intemediate depth water. When h/L larger than 1/2, it's called deep water. where h is depth, L is wave length(distance between to adjecent wave crests) for ocean, say h=1000m, if wave length > 20 km is still called shallow water though 1000m is not that shallow at all. For commonly seeng waves with L =10m, h <10/20=0.5m is called shallow water, h>10/2=5m is called deep water. We see that shallow water is really shallow, and deep water is not horriblely deep.

 August 30, 2004, 06:41 Re: shallow water VS deep water #10 Kel Guest   Posts: n/a Hello, I also write a fortran code for simple (linear) equations of 2-D shallow water. Unknown functions are u,v, and ksi (ksi is the free surface elevation over a reference plane). Can anybody suggest some test example for program debugging? Thanks.

 August 30, 2004, 11:56 Re: shallow water VS deep water #11 Wen Long Guest   Posts: n/a Go to the following website and download the Funwave, there are many examples in the documents. http://chinacat.coastal.udel.edu/~kirby/programs/ I think one of the best is Berkhoff Shoaling, for weakly nonlinear waves,

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