minimum water depth error

Adnan · 2015-09-20 16:05:01

respected sir ,

i am running software basement for my coupling 1D network and geting this error

*******************************************************************************
*!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! Error !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!*
*******************************************************************************
-> Newton-iteration in calculateZ(A) for cross section 'st4_3' failed after
reaching max #iteration (1000).
Requested A = 1.48703e+030
Current z = 0
A-Anew = 1000
[z0,z1] = [57.074, 67.34]
[A0,A1] = [0, 225.775]
Your minimum_water_depth might be the problem, try to vary your
minimum_water_depth

*******************************************************************************
*!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! Error !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!*
*******************************************************************************

how to solve this ?

regardz

Lukas Vonwiller · 2015-09-23 09:41:17

Hi Adnan

Do you start your simulation with dry initial conditions?
Try to get reasonable initial conditions for all your 1-D subdomains first!

Hope this helps!
Cheers, Lukas

Adnan · 2015-10-06 07:37:13

yes i choose dry condtions.

ok but what will be the suitable conditions to run ?

Lukas Vonwiller · 2015-10-06 08:57:11

Please try to produce reasonable initial condition by using e.g. initial condition of type 'backwater'.
Furthermore check your parameters in HYDRAULICS -> PARAMETERS -> SECTION_COMPUTATION, you might adapt for example 'min_interval', 'max_interval' (for type 'table') or change
to type 'iteration'.

Hope this helps!
cheers, Lukas

Adnan · 2015-10-08 06:33:08

Dear Lukas ,

my conditions are

as below

INITIAL {
type = dry
}
PARAMETER {
minimum_water_depth = 0.0001
SECTION_COMPUTATION {
type = iteration
precision = 0.0001
}
}
}

i am doing an urban flood modelling project in whch i am taking streets as channel and coupling them

for every channel my condition is same as above ,

regards

Adnan · 2015-10-08 08:25:39

further more my model is oneway 1d couple and

other thing is if you can make me a simple tutorial/run file on using the initial conditions other than dry that is ( backwater & continue ) would be appreciated .

thanks

Lukas Vonwiller · 2015-10-08 08:26:35

Hi Adnan

Did you try
INITIAL {
type = backwater
}
PARAMETER {
minimum_water_depth = 0.0001
SECTION_COMPUTATION {
type = table
max_interval= 0.001
min_interval= 0.0001
}
}
}

try to play with the parameters 'max_interval' and 'min_interval' for all your subdomains, even with dry initial condition.

hope this helps!
cheers, Lukas

Adnan · 2015-10-08 08:34:16

thanx for the help i will look into it and will tell you what i get from the above conditions

regards

Adnan · 2015-10-13 07:32:56

choosing the backwater option ask for parameters q_out and wse .

i tried with your specified conditions and i was able to run basement after a little tweaking in x-sections but after i change my hydrographs bsement starts giving the above errors again ,

Lukas Vonwiller · 2015-10-13 08:22:53

If you were able to run basement for a constant hydrograph, then use the result file '_restart' as a initial condition (continue) for all your future model runs!

Adnan · 2015-10-14 10:11:09

dear Lukas ,

i did as what you have said , but now i am having this issue

-> OpenMP: Computation is executed sequentially
-> Domain: Starting time loop
-> Domain: Run Time of the simulation= 0 sec
-> Domain: Finished simulation.

Lukas Vonwiller · 2015-10-14 10:39:12

Try to use 'start_time' = 0.0 or increase your simulation run in the TIMESTEP block.

Hope this helps!
cheers, lukas

Adnan · 2015-10-15 09:57:54

i have run the basement on constant hydro graph of 30 m^3/s and set them as initial condition for my other hydrograph . basement runs

but 30 cumecs is too much value . so i now want to run for 1 0r 0.5 cumecs but again i am having the same problem .

the other thing is how much the minimum water depth value should be used ? i am using 0.0001 default

also i am using cfl value 0.6 . is it ok ?

regards

Lukas Vonwiller · 2015-10-16 10:19:20

With such small discharges you will have very small flow depths, which will cause problems.
Try to use type table for section computation with very small intervalls.

With CFL=0.6 you will have quite high numerical diffusion.
As you can read in the help button of the GUI, the CFL should be as close as possible to 1.0.

Adnan · 2015-10-17 14:35:12

thanx lukas for the quick replies

User Forum of Software BASEMENT

#1 2015-09-20 16:05:01

minimum water depth error

#2 2015-09-23 09:41:17

Re: minimum water depth error

#3 2015-10-06 07:37:13

Re: minimum water depth error

#4 2015-10-06 08:57:11

Re: minimum water depth error

#5 2015-10-08 06:33:08

Re: minimum water depth error

#6 2015-10-08 08:25:39

Re: minimum water depth error

#7 2015-10-08 08:26:35

Re: minimum water depth error

#8 2015-10-08 08:34:16

Re: minimum water depth error

#9 2015-10-13 07:32:56

Re: minimum water depth error

#10 2015-10-13 08:22:53

Re: minimum water depth error

#11 2015-10-14 10:11:09

Re: minimum water depth error

#12 2015-10-14 10:39:12

Re: minimum water depth error

#13 2015-10-15 09:57:54

Re: minimum water depth error

#14 2015-10-16 10:19:20

Re: minimum water depth error

#15 2015-10-17 14:35:12

Re: minimum water depth error

Board footer