Jump to content
TUFLOW Forum
scott

Channel Flow Results

Recommended Posts

Hi,

I am running a model to compare flows and depths in a channel pre and post flood mitigation works. The mitigation works direct more flow to this particular channel which is being modelled in 1D as an 'S' type channel. The 2D results clearly show that more flow arrives at the channel as expected, but upon inspection of the 1D results (TS output) it is a little less clearer. My question is how does TUFLOW calculate the maximum flow in a 1D channel element? Is it calculated at the upstream end, the downstream end or is an average flow calculated for the length? From my results it appears that it is either the upstream end or an average value. Any help would be appreciated.

Cheers

Share this post


Link to post
Share on other sites

Scott,

May I recommend the .eof file to you? It will show you how the values that you specify in the 1d_nwk layer (or reference in the 1d_tab) are applied to the model, and in particular the calculated conveyance. The eof also contains a report of the flows, velocities, water levels, mass balance etc for each model node. Each node is suffixed by .1 or .2 to indicate either the upstream or downstream location of the channel although you can reference this against the TS output you've already looked at as not all nodes have .2 nodes (they are represented by the downstream .1 node).

Hope this helps and that I'm right!

Pete

Share this post


Link to post
Share on other sites

Hi,

I am running a model to compare flows and depths in a channel pre and post flood mitigation works. The mitigation works direct more flow to this particular channel which is being modelled in 1D as an 'S' type channel. The 2D results clearly show that more flow arrives at the channel as expected, but upon inspection of the 1D results (TS output) it is a little less clearer. My question is how does TUFLOW calculate the maximum flow in a 1D channel element? Is it calculated at the upstream end, the downstream end or is an average flow calculated for the length? From my results it appears that it is either the upstream end or an average value. Any help would be appreciated.

Cheers

Hi Scott,

As i understand, the TS output in 1D estry channel is an average of computed flows at u/s end and d/s end river cross-sections.

When an overtopping bank occurred in your case, the output flow in TS file would be different to flows at either d/s end or u/s end. When no overtopping occurred along this length, the channel flows = flows at u/s end node = flows d/d end node.

Hope this helps.

cheers,

Lei

Share this post


Link to post
Share on other sites

Hi Scott,

As i understand, the TS output in 1D estry channel is an average of computed flows at u/s end and d/s end river cross-sections.

When an overtopping bank occurred in your case, the output flow in TS file would be different to flows at either d/s end or u/s end. When no overtopping occurred along this length, the channel flows = flows at u/s end node = flows d/d end node.

Hope this helps.

cheers,

Lei

To chip in, it my understanding that flow is calculated in the middle of the pipe, not at either end at all! ESTRY has storage volumes in the nodes at the ends of channels or pipes, and the flow is calculated between them, so it is conceptually the mid-point, although mathematically it's just "between" in this case. I don't know how it handles and presents the flows added or removed when linked to 2D though, so not a very helpful contribution to this thread... :)

Share this post


Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.


×
×
  • Create New...