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Hello,

I have a canal and would like to install a turbine perpendicular to the flow half way along the length of the canal.

I have tried to triangulate the mesh and create a boundary conditions file with Blue Kenue. The issue however is that the boundary conditions only works around the perimeter of the mesh.

I've tried to use the closed line tool to create two seperate submeshes, however the closed line needs to be set at a constant value which would be a problem when mapping the varying bathmetry of a real river.

What I would like to do is create boundary conditions across the river with what I would imagine a negative prescribed flowrate to simulate the effect of a turbine.

I don't know if anyone would be able to help me out please?

Hi,

will you able to post the scope of your work included drawings and geometry file plus turbine?

I may able to help since I worked on this before and if you look at the user conference 2016 you can find an article on it.

are you working on Telemac 2D or 3D?

AMANJ

Dear Amanj,

Thank you for your reply.

In this case, i've ran a simulation without the turbine installed and ran a simulation that has run for 30 minutes. The full selafin file is too big to upload so i have included the bottom file.

What I would next like to do is run another simulation but with a turbine installed. the intended location of the turbine is on the image provided where I have changed the elevation to 25 metres. At the moment I need to know what approach to take first.

I do not have any drawings or geometry as it isn't a real example and am happy to use made up values as I need to learn how to do this should I get a real example to model in the future.

Well, as far as I know, we have two approaches to implement turbine. One is putting stress (drag) on nodes that representing turbine drag force ( coefficient) and treat as bridge piers BUT with actual turbine drag ( friction) since the flow is still passing through it ( not blockage 100%). Or the second approach by finding nodes affected by the turbine using poy function to find them inside TELEMAC system and then add the drag force as source/sink to the hydrodynamic model ( system of equations where one of the right terms is source/sink) in the momentum equations.

Hope this helps you even though a bit confusing for beginners!

AMANJ

Dear Amanj,

Thank you for your help, it certainly provides me with direction.

As a new user, could I ask how I would put drag on the selected nodes through both methods you have mentioned?

Hi,

for the second approach please refer to the Telemac user conference 2015 page 182 Using the DRAGFO subroutine to model Tidal
Energy Converters in Telemac-2D
for the first approach as I said you have to treat nodes as a bridge pier by introducing friction coefficient determined based on drag force of the turbine. One more thing is to try to do the sensitivity analysis to find out the impact of nodes affected by the turbine and observe the wake behind the turbine. PleaSE ALSO read about different turbulent models in detail since it has a great impact on the shape and strength of the wake behind and around the turbine.

AMANJ

That's great, thanks for you all your help

no problem.

Amanj