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[lesmodel]

Dear developpers,

Thanks very much for your contribution to the openLB.

In the case cylinder2d. the Re is 20, latticeU is 0.02, charU is 0.2.
When I simply change the Re to 100, your know, the flow pattern
is changed, what is the new velocity for inflow?

[mathias]

There is no new inflow velocity. The viscosity is chenaged simply. Best Mathias

[lesmodel]

Dear mathias,
Thanks very much for your quick response. I have another question, in the case of aorta3d. the Re is decided by CharU, CharL and CharNu, if I change the CharU to obtain the different Re, what’s the new velocity for inflow?

[mgaedtke]

Hello,

in aorta.cpp line 174 and following the boundary velocity is set with SinusStartScale<T,int> nSinusStartScale( iTperiod,converter.getCharU() ); So, after the start time period of 0.5s, the velocity at the inlet is a circular poiseuille profile with CharU beein the maximum velocity. Change CharU in the converter, and you will get this velocity at your inlet.

Best, Max

[lesmodel]

Dear Max,
in aorta.cpp line174, it’s ‘SinusStartScale<T,int> nSinusStartScale( iTperiod,converter.getLatticeU() )’, the velocity at the inlet is a circular poiseuille profile with LatticeU beein the maximum velocity, it’s LatticeU not CharU. Looking forward to your reply.

[mgaedtke]

Hey, yes you are right, sorry for the missunderstanding. We set LatticeU here, which is the converterted physical CharU. So if you change the CharU in the converter construction, you will end up with this value beeing the physical velocity for your simulation.

Best, Max

[esposagroup]

helpful post nice reply

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