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Hi,

I have simulated a river and released particles from a single source. I have attached a figure showing particles released at 10 minute intervals over 24 hours. The river flow is transient (tidally influenced) and the flow at the final timestep is shown. The issue is that particles are following streamlines and do not exhibit any turbulent or diffusive properties. Is there any way to incorporate turbulent effects such as a random-walk model based on turbulent kinetic energy or other diffusivity?

Thanks!
-Simon

Hi Simon,

Check out the PSed model integrated in Blue Kenue.
It uses a random walk scheme to model diffusion.
If you set Sediment Density = 1000 kg/m3 and VarLog2D = 0 you
will have neutrally buoyant particles.

You supply the HD (depth and currents) from a Telemac or other
model as input. It's very easy to setup and runs fast.

Hope this helps... Martin

Hello,

We do have a random walk model for oil particles and algae, but we lack the (small ?) development and the keyword that would allow to use it for other particles. So provisional answer is no but I'll see with colleagues if it would be easy to do it soon.

With best regards,

Jean-Michel Hervouet

I agree, a simple random-walk model for drogues would be very useful. I hope you guys can build it!

Hi Simon,

If you want to use a stochastic diffusion with particles in 2D, it has been done. You just need to put the following additional keyword in the Telemac steering file :

STOCHASTIC DIFFUSION MODEL (= 0 or 1) (p.39 of the manual)

All options concerning particles in Telemac-2D are explained in the manual "Adding a particle transport module to Telemac-2D with applications to algae blooms and oil spills" which is available in this website.

Best regards,

Cédric

Thank you Cédric, the stochastic diffusion model worked perfectly.

Cheers,
Simon