[shovaliye2]

hi. I am simulating flow around hydrofoil with K Epsilon method (realizable)

in boundary conditions and inlet, there are two parameters : turbulent kinetic energy and turbulent dissipation rate

how can I determine proper magnitudes for these two parameters?

[vinerm]

The relevant information is available in Fluent's User guide

https://www.afs.enea.it/project/nept....htm#ke-params

[shovaliye2]

I had seen this user guide before but I don't know how to calculate u' and uavg

can I use equations 1 and 2 and approximation table in below paper for my case?
https://www.simscale.com/forum/t/def...nditions/80895

[vinerm]

Average velocity is the velocity at the inlet. As far as is concerned, you have to assume, say 5% or 10% of average velocity. You can use the data from the table.

[shovaliye2]

Originally Posted by vinerm

Average velocity is the velocity at the inlet. As far as is concerned, you have to assume, say 5% or 10% of average velocity. You can use the data from the table.

so you mean u'= 5% or 10% of average velocity?

and I have another question. in user guide there is a formula for length scale l which is l=0.07L
what is L for my case? is this chord length of hydrofoil?

K and epsilon are independent from directions of inlet velocity (vx and vy) and only depends on magnitude of inlet velocity?

[vinerm]

Answers to all your questions is a yes.

[shovaliye2]

thanks a lot. you have helped me these days a lot.