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SAKTI September 14, 2008 21:59

Multicomponent with Temperature dependent
Dear All,

I want to simulate the real exhaust gas component, the case is temperature dependent. Which thermophysical properties should I use? The multicomponent option doest concern the temperature dependent right? how about the polynomial option? will it concern the multicomponent effect?

Best regards Sakti

usker September 14, 2008 23:48

Re: Multicomponent with Temperature dependent
Multicomponent means concentration dependent, this option is suitable for multi-component mixtures. Depending on the density setting, STAR uses a constant specific heat Cv or Cp (or any other thermophysical property) for the background fluid. It also uses constant specific heats for any additional scalars present to calculate a mixture specific heat weighted according to the local concentration of each component.

Polynomial calculates the specific heat Cp (or any other thermophysical property) as a polynomial function of temperature (non-linear change of specific heat with temperature). If you click Define/Edit polynomial, it opens a special Polynomial Function Definition dialog in which polynomial coefficients may be created or edited, as necessary.


SAKTI September 15, 2008 01:20

Re: Multicomponent with Temperature dependent
Dear Mr. Usker

Thank you for your reply, what if the properties value both concentration and temperature dependent?

regards Byan

usker September 15, 2008 22:09

Re: Multicomponent with Temperature dependent
Then your Density will be a function of pressure and temperature.

Molecular Viscosity - MultiComponent, (if your Viscosity is temperature dependent, then you have to use Sutherland. Please, refer to Star-CD Methodology.

Specific Heat - Polynomial

Conductivity - Constant or Polynomial (usually Constant, but it depends on the flow conditions)

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