So this is off-topic, but I know that we have a number of =
CFD experts floating around on the lists...

Has anyone worked with t= he 1D variable-area Euler equations before?

--

John

--001a11c3813662471604de92e023--Has anyone worked with t= he 1D variable-area Euler equations before?

I'd like=
to develop an SUPG formulation based on the typical quasi-linear form, in =
particular for general (non-ideal gas) equations of state.

As far as I can tell, the variable-area aspect doesn=
9;t change the flux Jacobian matrix... it is the same as for the constant-a=
rea equations.

But I must be making a very basic (=
and stupid!) math mistake somewhere: when I multiply (what I believe to be)=
the flux Jacobian matrix by the derivative of the conserved variables, I d=
on't recover dF/dx except in the case of an ideal gas. =A0The attached =
slides go into additional detail... I'd be grateful if someone could ta=
ke a look and point me in the right direction -- this has been driving me c=
razy for a couple days now.

Note that one small, but possibly significant, differen=
ce between the ideal gas EOS and a general EOS is that the flux vector F is=
not necessarily a "homogeneous function of degree 1" in the gene=
ral case... =A0I don't think this has any direct bearing on the quasi-l=
inear form, but I found it initially surprising.

--

John