max dpeth

When I was running the model, it kept sending me the warning and error messages.

The Warning No.144: Steady State Initial conditions calculation: Water Level at xxx exceeded max depth criteria
Error No.25: At the h-point xxx, the water depth greater than 4 times max depth

Both of them have mentioned the term of 'max depth'.

My question is how MIKE 11 defines and calculates 'max depth' for each cross section? Does the 'max depth' , to some extent, relate to Courant Number or initial water depth?
To see the 'max depth' related to the initial water depth or not,  I changed my initial water depth (global value) to different values, but the max depth criteria for each cross section didn't change at all. Hence, the max depth is nothing to do with the value of initial water depth.


Another thing is, the training material from year 2009 says the Courant Number must be [b]less than 1[/b] for the model stability. But when I checked the manual of MIKE 11 (version 2012), on page 26, it says ' MIKE 11 applies a 6-point Abbott scheme for solving the equation which does not have the typical Cournat number below one demand. Good results are obtained up to Cournat numbers [b]as high as 10-20[/b]'. I am just so confused about this conflict.

I really appreciate if someone can reply me.


Best Wishes
Yvonne

I have figured out the max depth generally is determined by the points on marker1/3 in the cross section editor.

I believe the training material you are refering to will discuss the stability criteria from the point of an explicit numerical scheme. Please note that MIKE 11 uses an implicit scheme and thus the stability analysis (based on the linearised equations) will result in an unconditionally stable scheme though note that the non-linear are not taken into account and in practice you will be looking at a Courant number in the range you mention. I hope this clears up the confussion

Good luck

For the first question, regarding WL exceed after given reference level cause error. In order to solve this problem, there is an easiest method. Go to the "bin" folder of DHI software installed and find the file "Mike 11.ini".
copy this file to a different location and find the following parameter.
"WL_EXCEEDANCE_FACTOR=4" change this 4 into 20 or bit more. then save the file and copy and replace back to the original location. I hope this will solve your problem. This method will stable your model.