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Setting Boundary Condition for Transient Navier Stokes
Posted 2010年1月14日 GMT-5 21:10 Studies & Solvers 1 Reply
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Hi all!
SETTING BOUNDARY CONDITION FOR TRANSIENT NAVIER STOKES
I want to set a boundary (i.e. inlet) with constant flow rate of 1.11 m/s.
In "Constant" option, I have set
u_in = 1.11 [m/s]
However, I cannot get initial value with the solver. I need the initial value (at t=0) for the transient solver to begin.
In the second case, I tried setting the flow rate at
u0 = 1.11*(t[1/s])
The transient solver (i.e. BiCGStab) could give a solution but the velocity is increasing with time and this is not what I want.
Basically, my case is very simple. A step increase of constant magnitude (i.e. constant velocity). How should I set me boundary condition in order for the solver to be able to obtain constant inlet flow?
Please help me! Thank you very much!
SETTING BOUNDARY CONDITION FOR TRANSIENT NAVIER STOKES
I want to set a boundary (i.e. inlet) with constant flow rate of 1.11 m/s.
In "Constant" option, I have set
u_in = 1.11 [m/s]
However, I cannot get initial value with the solver. I need the initial value (at t=0) for the transient solver to begin.
In the second case, I tried setting the flow rate at
u0 = 1.11*(t[1/s])
The transient solver (i.e. BiCGStab) could give a solution but the velocity is increasing with time and this is not what I want.
Basically, my case is very simple. A step increase of constant magnitude (i.e. constant velocity). How should I set me boundary condition in order for the solver to be able to obtain constant inlet flow?
Please help me! Thank you very much!
1 Reply Last Post 2010年1月15日 GMT-5 02:50
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Posted:
1 decade ago
Hi
if you want to study th step, I wouuld trie one of the "heaviside" functions to make a short but smooth step, this helps the solvers to follow the non-linearities
Good lukc
Ivar
if you want to study th step, I wouuld trie one of the "heaviside" functions to make a short but smooth step, this helps the solvers to follow the non-linearities
Good lukc
Ivar