Dear all

I run the Xoodles\pitzDaily3D, use the default 'combustionProperties' values.
and run Xoodles\pitzDaily, set 'ignite' is 'yes',but the two cases do not ignite and combustion. when I increase the value of 'strength' of 'ignitionSites' , the cases ignite,but reach error soon,
"attempt to use janafThermo<equationofstate> out of temperature range 200 -> 5000; T = 192.877 "

I wonder how to run the cases Xoodles\pitzDaily3D and Xoodles\pitzDaily with combustion? what are the meaning of the following Properties? when 'strength' is '2', means how high temperature? and what is the 'ignitionSphereFraction' , 'ignitionThickness' and 'ignitionKernelArea' ?

thanks !

qf

--------------------------------------------------


ignitionSites
(

{
location (0 0 0);
diameter 0.003;
start 0;
duration 0.001;
strength 2;
}
);

ignitionSphereFraction 1;

ignitionThickness ignitionThickness [0 1 0 0 0 0 0] 0;

ignitionCircleFraction 0;

ignitionKernelArea ignitionKernelArea [0 2 0 0 0 0 0] 0;

----------------------------------------------------

Anyone can help me to get the correct results of Xoodles\pitzDaily and XoodlespitzDaily3D ?

thanks

[arkangel]

BUMP

[arkangel]

I run the case again this time i set the values for boundary conditions to adiabaticWall and run to the end

[hannes]

Hello qinfei,

at least in my case, which had well initialised temperature and combustion progress fields from another run with a different combustion model, I found this problem (janafThermo out of temperature range) to arise in the newton solver in "specieThermo".

I suppose, that due to an unlucky shape of h(T) or because of the break in h(T) and cp(T) at Tcommon, the calculated tangent has a too low positive ascent at certain temperatures and the newton iteration gives very low or even negative temperatures.
When the newton solver tries to evaluate the janaf polynomials for the next iteration, the error occurs.

For a very quick and very dirty fix, I inserted a
if (Tnew<TMIN) return TMIN;
at line 74 in $FOAM_SRC/thermophysicalModels/specie/thermo/specieThermo/specieThermoI.H with TMIN being of course problem specific.

Best regards, Hannes