[FLASH-USERS] Mass scalar question

[John ZuHone]

William,

Mass scalars are defined from 0 to 1, so you need them to be Z = Z_wanted, as you said.

However, the way you set this up is up to you and whatever is most convenient with respect to the details of your initialization. You may find it easier to set your mass scalar directly, such as:

solnData(METL_MSCALAR,i,j,k) = metal_frac ! something between 0 and 1

or it may be easier to set it up in this way, if your initialization has a metal density of some kind.

solnData(METL_MSCALAR,i,j,k) = dens_metal / solnData(DENS_VAR,i,j,k)

But the main point is that your mass scalar is a *fraction*, and not a density.

Best,

John ZuHone

On Oct 13, 2010, at 10:56 AM, William Gray wrote:

> Hello FLASH users,
> 
> I have a hopefully simple question. I am wondering what is the correct method of defining a mass scalar. If I have a quantity Z (in my case I am using this to track metals) that I have defined as a mass scalar. Should it be defined as Z = Z_wanted*density or as Z = Z_wanted?  I am interested in this because I want to make sure that this quantity is advected correctly.
> 
> 
> Thanks for your help,
> 
> William Gray
> PhD Candidate, Astrophysics
> Arizona State University