TELEMAC-MASCARET Forum: The best way to model inflow to dry bed (1/1)

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TOPIC: The best way to model inflow to dry bed

The best way to model inflow to dry bed 6 years 11 months ago #28427

shenh
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Posts: 148
Thank you received: 37

I am setting up a t2d model with single inflow boundary and with dry bed as initial conditions. I understand with inflow boundary i need to have some water at the inflow boundary for the program to calculate inflow velocity. I can use continued computation to accomplish this. In the initial conditions file, I will set initial depth to very small value (say 0.01 m) only for the nodes at the inflow boundary, and zero depth for elsewhere.

Alternatively, i can use source points at the inflow boundary nodes. I will divide the temporal flow by the total number of nodes at inflow boundary, and set the new hydrograph in the source file.

Could anyone comment on both methods? I am also wondering whether there is a better way to model this.

Your inputs are greatly appreciated,

Hailiang

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The best way to model inflow to dry bed 6 years 11 months ago #28428

konsonaut OFFLINE openTELEMAC Guru Posts: 413 Thank you received: 144	Hi, option 1 should work normally. We use it to initialize flood simulations. With best regards, Clemens
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The best way to model inflow to dry bed 6 years 11 months ago #28437

shenh OFFLINE Senior Boarder Posts: 148 Thank you received: 37	Thanks. Have you compared option 1 with the source method? I am wondering how different the results could be. How the code handle both methods internally? Hailiang
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The best way to model inflow to dry bed 6 years 11 months ago #28440

konsonaut OFFLINE openTELEMAC Guru Posts: 413 Thank you received: 144	Hi, what I remember this is well explained in the user manual. The fundamental difference between the methods is that by prescribing the discharge by means of source terms, the momentum is not accounted. Hence, depending on your case, you should prescribe also velocities at the source points. I never did this. Best regards, Clemens
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The best way to model inflow to dry bed 6 years 11 months ago #28453

riadh	Hello Yes as said by Clemens, the option with soruces will give less physical result locally since it will just introduce water without preveleged direction for the velocity. This will give wrong momentum in the vicinity of the boundary but also could even distord all the hydrodynamics downstream. Conclusion: option1 is highly recommended. with my kind regards Riadh
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The best way to model inflow to dry bed 6 years 6 months ago #30149

Sameer Akhtari	Hello everyone, I have read this topic and I want to know how you assign a very small water depth as initial conditions for the liquid boundaries and zero else where, I mean by the keyword INITIAL CONDITIONS? If yes how? because this keyword then needs a single value for the entire domain. Thank you in advance.
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The best way to model inflow to dry bed 6 years 6 months ago #30190

riadh	Hello You can not use a keyword to introduce wome water in a particular place. Instead, you can use either Blue Kenue or fortran user. You can see for instance the fortran file of examples dambreak or malpasset where subroutine condin.f is used. Subroutine inpoly.f (bief) can help you to detect nodes within a polygone. with my best regards Riadh Ata
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