[chripasch]

Dear experts,
following this website of FLOW-3D:

https://www.flow3d.com/hydraulic-boundary-conditions/

it is stated "To reduce the “profile-development-length” is the goal of a third new type of hydraulic boundary conditions, the Inlet Profile, which is currently under development." Does anyone know when we can expect this new feature?

Thanks for any hint and best regards

[bfox48]

There were some complications with this development that caused its delay. It is currently not scheduled to be included in the 2017 11.3 release.

[chripasch]

Thanks for this information. Such a pity.

[bfox48]

A grid overlay boundary is a potential alternative for some types of simulations. You can also define an inlet velocity profile through customization, but you would need code that yourself and have access to the necessary FORTRAN compilers

[chripasch]

Yes, thanks for this hint. I used the grid overlay option in combination with utilizing several mesh blocks to reproduce the deskired velocity field quite well. It is a big effort, but it works satisfactorily.

[huythanhdhtlgmail.com]

Dear brian,
Can you tell me how to define velocity profile at inlet boundary in FLOW3D? I want to give the velocity profile at inlet of the flume with turbulence modeling, I failed when validation with my experiment. Do you have any introduction or anything else to help me building the code? Thanks so much!

[chripasch]

Hi,
you could reproduce the desired velocity field by means of using several mesh blocks and then perform a restart and grid overlay simulation of this (lets call it) pre-simulation. I did so to e.g. obtain a nice logarithmic velocity profile quite quickly downstream of the inlet boundary by using 10 mesh blocks along the water depth.

Bests
Chris

[huythanhdhtlgmail.com]

Dear Chris,
you mean of using 10 mesh blocks along the water depth at the first running (pre-simulation) or in the restart simulation combination with grid overlay (second running)? if you do it in the first running, why did you do that? Can you explain to me? I really don't understand how to do it. Thanks for your help!