[Nek5000-users] Variable density flows

[nek5000-users at lists.mcs.anl.gov]

I am not sure that what you are solving for  c  is a normalized scalar like a mass fraction Y for example 
If c is not normalized May be the formulation is equivalent to
C= rho* Y where y is a normalized scalar and rho is the total density..

Finally check mass conservation
By integrating over the volume of the channel, the density equation
d/dt integral(rho) + integral (u. Grad rho) =error 
And see how error changes over time

Ammar

Sent from my iPhone

> On Oct 13, 2013, at 1:46 AM, nek5000-users at lists.mcs.anl.gov wrote:
> 
> 
>> On Sun, Oct 13, 2013 at 10:35 AM, <nek5000-users at lists.mcs.anl.gov> wrote:
>> You can also try error function like profile with 0 value at the inlet and increases to a peak somewhere and stays constant up to the exit so gradient is0 at the exit
>> Insulation normally refers to the diffusive flux (first form)
>> Ammar
> 
> Thanks for the tips. I am using a smoothed initial condition for scalar now. However after some time the scalar does not stay within [0,1] which is important. My time step is already small with cfl ~= 0.1. What can I do to get better behaviour of the scalar ?
> 
> The diffusion coefficient for my scalar is quite small, D = 5*10^(-5).
> 
> Regards
> praveen
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