Question about heat capacity and conductivity under thermal equilibrium

[Wayne Shen]

Dear,

I want to use Cantera to draw the function of heat capacity and conductivity as a function of gas temperature under thermal equilibrium. However, the results do not agree with the other results. Does any expert know where I'm wrong in my code?

These are my results (120 mbar CO2 as initial gas):

These are other paper results (sourced from https://www.sciencedirect.com/science/article/pii/S1385894724095639 ):

Thank you in advance for your kind help!

Best,

Wayne

[Steven DeCaluwe]

Hi Wayne,

In the paper you reference, the paragraph above that figure describes the features of the figure.  

My simple understanding is that their Cp calculation implicitly factors in energies of reactions - the peaks in their Cp calculation, they note, accompanies dissociation reactions, where the heat of reaction is part of the dh/dT.  Cantera’s Cp calculation is for a given composition at the stated conditions.  I didn’t read far enough to understand how that impacts thermal conductivity.

For Cp, I’m wondering if you could replicate this by manually calculating dH/dT at constant pressure.

1. Save specific enthalpy for current T.

2. Increment T by some small amount.

3. Equilibrate at constant TP

4. Save new specific enthalpy and manually calculate Cp[i] = (h[i] - h[i-1]) / (T[i] - T[i-1]) 

Cheers,

Steven

On Jul 8, 2025, at 2:33 AM, Wayne Shen <meled...@gmail.com> wrote:

Dear,

I want to use Cantera to draw the function of heat capacity and conductivity as a function of gas temperature under thermal equilibrium. However, the results do not agree with the other results. Does any expert know where I'm wrong in my code?

These are my results (120 mbar CO2 as initial gas):

<My results.png>

These are other paper results (sourced from https://www.sciencedirect.com/science/article/pii/S1385894724095639 ):

<Screenshot 2025-07-08 103152.png>

Thank you in advance for your kind help!

Best,

Wayne

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<Code.py><gri30_highT.yaml><Screenshot 2025-07-08 103152.png><My results.png>

[Wayne Shen]

Dear  Steven，

Thank you so much for your kind reply.

The problem has been solved now:)

Best,

Qinghao

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