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The original post
about “Wormhole Culverts” received thousands of hits, and many
HEC-RAS users are now applying this method regularly in their models; but how
valid are the hydraulics over the full range of open channel flow, pressure
flow, and weir flow? Given the amount of use they are getting, it’s high time
to put wormhole culverts to the test!
This test run
assesses wormhole culverts against other approaches for modelling hydraulic
structures in 1D and 2D model reaches.
The results show very
similar water surface profiles between the various methods. The wormhole method
provides the ability to correctly display terrain data for roadways and bridge
decks in viewing plan and profile results.
While coupled 1D-2D
reaches would still be required for detailed bridge designs in HEC-RAS,
wormhole culverts appear to be a viable means of accounting for bridges and
culverts with substantial terrain detail between the inlet and outlet that is
subject to 2-dimensional flood flows.
Is the Z-shape for the Wormhole Culverts mandatory ? Or is any shape possible ?
ReplyDeletePhilippe
I guess not. It needs to double back on itself so that the outlet is on the correct side of the connection line. Besides that, I think you're free to make it whatever shape you want. What shape did you have in mind, and why?
DeleteThank you for your answer. No particulary shape in mind, just a question. Is there a significative impact if the outlet is on the wrong side ?
ReplyDeleteI think about wormhole culverts to inject flow at a specific place in a 2D-model. Do you think it could possible to link a storage area outside the 2D area with this method ?
Philippe
If the outlet is on the wrong side, yes, it would be a significant impact. I would try to avoid this. Wormhole culverts can be used to inject flow on the interior of a 2D area. But instead of linking it to an external storage area, you have to create some "dummy" terrain storage inside your 2D area . Preferably in a place where you'll have no flow. Then link up your wormhole culvert from that dummy storage to the point where you want to inject flow.
DeleteVery cool workaround. Do you know approximately when the next release is scheduled, or if the next release will incorporate XS creation/editing capabilities in RAS (GeoRAS replacement)?
ReplyDeleteI would guess about 1 to 2 years from now. And yes, HEC intends to do away with GeoRAS and have all geometry preprocessing done within HEC-RAS for the next release.
Deleteso 1 to 2 years before 5.1 is out? That is interesting as the HEC UK training courses states they are showing 5.1 in July.
DeleteAll I can tell you is what I've heard. Maybe UK is getting a sneak peak into new features in 5.1.
DeleteThanks Chris... Whenever I do my daily refresh of your blog I am always hoping for impending news of the 5.1 release. Good to know what the actual timeline is. :)
DeleteYou're welcome! I'll be sure to announce the new release as soon as it comes out.
Delete