DAMBRK Problems

We have recently bought the BREACH and DAMBRK program. BREACH has
worked as expected, but DAMBRK which I have used with success before has
been troublesome. Actually I dont get any results at all, even though I have
entered only a fraction of the geometry, and no dams. I have attached
the actual DAMBRK file and hope for a quick response.

The error message I get is: "Floating point error occured, computation
processing suspended. Abort comp. proc. (Y/N)? If I answered yes, the
initial condition were calculated but nothing more (domain error in
pow). Inspections of the initial condition table showed negative values
for the hydraulic depth.

Please help me to find a way out of this. I have tryed to modify the
geometry, the boundary conditions the inflow hydrograph, but with no
success.

As our documentation states, you must have the same number of top widths at each cross- section. I deleted some of the top widths at cross-sections so that the same number exists at each cross-section. Also, you need to turn on the mixed flow algorithm since some of your model is quite steep and the flow is supercritical. And, I had problems at the downstream most cross-section 5.71, so I deleted it and the model runs (as is included in the ZIP file). You should be able to further manipulate cross-section 5.71 to make it operate.

Sincerely,

Chris Maeder, M.S.
Senior Technical Engineer
BOSS International