Search found 6 matches

by mapeifeng
Thu Oct 25, 2012 7:24 am
Forum: ROMS Problems
Topic: Spatial oscillation in bottom stress for a steady flow
Replies: 5
Views: 3202

Re: Spatial oscillation in bottom stress for a steady flow

Thanks for the help. I also tried a couple of tests with uniform vertical spacing, which does help improve the results. When using 20 uniform sigma layers, for the case of L=100km and RDRG2=0.1, oscillations do not show up until DT=60s. I have looked at some cases with LOGDRAG. The results depend on...
by mapeifeng
Wed Oct 24, 2012 2:45 am
Forum: ROMS Problems
Topic: Spatial oscillation in bottom stress for a steady flow
Replies: 5
Views: 3202

Re: Spatial oscillation in bottom stress for a steady flow

I noted that after uploading the header file. So I ran a case with correct spelling: #define UV_SMAG O RINSKY. The results are slightly different, but the oscillations remain. I also tried different advection schemes and got a little different but still oscillating results. I also ran a few tests in...
by mapeifeng
Tue Oct 23, 2012 6:51 am
Forum: ROMS Bugs
Topic: water depth in calculating wave orbital velocity
Replies: 3
Views: 4056

Re: water depth in calculating wave orbital velocity

Thanks a lot for the comments. I agree that SWAN should be coupled in order to predict more accurate wave characteristics and the neglect of "zeta" in the simple formulation usually makes minor differences although adding "zeta" should make the calculation more physically consist...
by mapeifeng
Fri Oct 19, 2012 8:37 am
Forum: ROMS Bugs
Topic: water depth in calculating wave orbital velocity
Replies: 3
Views: 4056

water depth in calculating wave orbital velocity

In the BBL models, the still water depth h is used to compute wave bottom orbital velocity if *_CALC_UB is defined such as that of ssw_bbl below. I think total water depth h+zeta should be a more appropriate one to be used here as in shallow waters the surface elevation can change water depth substa...
by mapeifeng
Fri Oct 19, 2012 7:39 am
Forum: ROMS Problems
Topic: Spatial oscillation in bottom stress for a steady flow
Replies: 5
Views: 3202

Re: Spatial oscillation in bottom stress for a steady flow

Since I have been using POM, I ran the same test with POM and found that, for this particular case, POM can predict non-oscillating bottom stress at a larger time step of DT = 120sec (The bottom stress along the center line of the channel is shown below). This makes me a bit confused as, due to the ...
by mapeifeng
Tue Oct 16, 2012 9:11 am
Forum: ROMS Problems
Topic: Spatial oscillation in bottom stress for a steady flow
Replies: 5
Views: 3202

Spatial oscillation in bottom stress for a steady flow

Dear all, I got a difficulty when simulating a steady flow in an open channel of 100km length, 10km width and 10m still water depth. "Lm == 50, Mm == 3, N == 20" are specified. Uniform condition is assumed in the north-south direction. The steady flow is driven by prescribed constant flow ...