Unexpected fluctuation in total emissivity before the temperature T=1000 K

[ahsadeghi]

Hi,
The values for total emissivity have some unexpected fluctuations and bumps before the temperature 1000 K with the relative minimums at the temperatures where the experimental data were reported [Wakatsuki, 2005]. Does anyone know why it happens and where it is calculated or interpolated? Please see the attached figure for gas Heptane for total emissivity which is calculated by ((1-total_transmissivity)).

[ahsadeghi]

Hi @gforney, Could you help me?

[rmcdermo]

This may take us some time to look at. We do not run RADCAL off line very often. Please be patient.

[rmcdermo]

@drjfloyd can you take a look at this? Does stand alone RADCAL actually give a continuous function EMISSIVITY(T)? It is not clear to me where the blue line comes from versus where the black dots come from.

[drjfloyd]

ahsadeghi,

Where did the blue line and the black dots come from? Is the blue line FDS or are you running RADCAL? Can you attach the input you are using?

[ahsadeghi]

I run Radcal for different temperatures and then plot this (as I explained in the question topic).

[ahsadeghi]

Do you know how Radcal calculates SNB parameters at the temperatures other than the FTIR experiment temperatures? In which part of the code it is?

[drjfloyd]

None of the current development team were part of the development of RADCAL. The original RADCAL source and the theory manual for RADCAL can be found here: https://github.com/firemodels/radcal

If you ran RADCAL as a standalone code using the RADCAL namelist format can you attach the input file you used.