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Hi,

I have a validated 2D tidal hydrodynamic model of a region in the Arabian Gulf for which I am currently studying. I am assessing current speeds within a proposed inland canal/ channel (10m wide) where current speeds are extremely small (less than 0.1m/s).
I am interested in determining the head difference between two points in the canal due to differences in the free surface levels to plot against flow rates. I have performed this analysis for larger flow rates and found a correlation between positive head and positive flow rate (and vice verca) in previous models. However in this case there doesn't seem to be any correlation which I find a little bit strange. Am I overlooking something here or are there problems that may arise because the variation in free surface is extremely low. I have included a plot of flow rates vs head difference for reference below.
Thanks in advance





Regards,
Toby

Hello

We have too few informations about your model (mesh, boundaries, tide effects, wetting and drying, calibration, etc...). We can not give straightforward instructions.
The variations of free surface and velocities are extremeley low. You are, thus, deeply in the margin of uncertainties (of measures, calibrations (choice of friction coefficients), input data, mesh discretization etc.). That's why, in my opinion, the random variation of the head can not be exploited significantly.
A last recommendation, use the double precision format for your geometry file and particularly for your result file, this could help to minimize trancation errors. (use RESULT FILE FORMAT = 'serafind', GEOMETRY FILE FORMAT='serafind' (need to be generated in double precision with mesh generator, otherwise useless)).

I hopte that this helps

with my best regards

Riadh