Re: Crossing profile problem

Dear Matthew,
are the profiles consistently sub- or supercritical in the areas where you have crossing? If not, then that would account for it.

--Karl

Matt,

Have looked at your model. The supplied results have no EG values (I was trying to see what the crossing at 17.25 was operating under - inlet or outlet control). When I re-run the simulation the results came out as would be expected - i.e. no crossing profiles.

Regards
Mike Vaughan BEng (Hons) CEng MICE Chartered Civil Engineer
VaughanM@pbworld.com

Fellow Hec-Users,

I am modeling 4 steady flow profiles using Hec-Ras 2.2. Unfortunately, the profiles cross one another for about 3500' from the upstream end flowing through or over 14 structures. I have been unable to de-bug the model despite a thorough check of the flows and manipulation of the ineffective flow areas and mannings "n". Does anyone have any general guidelines for troubleshooting crossing profiles? If anyone has the time, I have attached the project file (matt.zip). Any help would be greatly appreciated.

Thank you,
Matthew P. Fischer
Taylor Engineering, Inc.

Mike,

I don't understand your email. Did you change anything to Matt's model/file? What was it that you did to eliminate the crossing profiles?

We've had the same problem of dealing with crossing profiles. We haven't had flows that were in the sub- or supercritical regime as suggested by Karl. Attempts to fix the problem involved modifying the ineffective flow areas. We have someone helping us deal with the problem and hope to learn from him what was done to solve the problem.

Melissa C. Henderson, E.I.T.
mchenderson@lan-inc.com

Melissa,

I did absolutely nothing! except resimulated the model here. The issued version contained a results file with no Energy Grade answers in it. Whilst the original profile did show a crossing 100 and 500 year hydraulic surface, my HEC RAS was not happy about showing the graphic. When I re-ran the model - everything was fine.

Guys,

Is everyone using V2.21? I thought that the original problem was encountered in a model run in that version.

Be careful - There is a bug in V3.0 that makes it default to normal depth under certain circumstances.

Michael E. Fanning
Milone & MacBroom, Inc.

I'm using V3.0.1 and encountered the problem.

Melissa C. Henderson, E.I.T.
mchenderson@lan-inc.com