unexpected head loss in model

[bland]

TLDR: model is producing unexpected head loss results between upper and lower sections.

I am fairly new to hec-ras, I am currently working on a 1D model using steady flow conditions. The body of water I am modelling is rather wide, and contains a change in elevation and drastically narrows before widening again. I have set up my model and I am able to run it, however the water surface profiles are not as I expected them. I expected the head loss between the lower and upper sections as shown below to increase as the flow increases, however that is not the case. The head loss vs flow inconsistently increases and decreases. I have checked my boundary conditions and cross sections and cannot to see anything wrong. Any advice on how to trouble shoot this problem is greatly appreciated!

[Jarvus]

It is hard to know for sure. Plot the energy grade line. It may be that the water surface is dropping because the velocity head is increasing where it “drastically narrows”.

[Author]

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