[magicbretzel]

Hi,

I am running some IC spark-ignited engine simulations, and I am running into some errors outputted by Converge when I use a fine mesh. More precisely, I get this warning followed by this error message:

(Rank 8) WARNING: [ 365] it = 6000, it_out = 6000, extrapolating on the temperature calculation.
WARNING: [3467] Temperature extrapolation error found at cell 65104, located at (6.25e-05, -7.115e-05, -0.00440044), in region 0, whose level=11
ERROR: The temperature is greater than max_temp in calc_temp_fraction
ncyc 15258; Crank -39.699 (deg); dt= 1.000000000e-07 (dt_recover)


What is this due to? And why does it only happen when I run on a finer mesh?

For info, I have a source activated at a crank angle of -40 degrees, depositing 0.15 J over a sphere with a radius of 0.5 mm, and a maximum temperature of 60000 K . This angle coincides with the appearance of these error messages. Depending on what is needed, I will be happy to provide more details. If that can help, I put the input files here:

https://jmp.sh/4mqfiMC

Many thanks!
Guillaume

[magicbretzel]

Quick update: is it simply due to the fact that I am depositing too much energy in a short time and that causes the temperature locally to reach the maximum value, hence the error message?

Thank you,
Guillaume

[nitesh.attal]

Originally Posted by magicbretzel

Quick update: is it simply due to the fact that I am depositing too much energy in a short time and that causes the temperature locally to reach the maximum value, hence the error message?

Thank you,
Guillaume

Hello,


It may very well be that you are dumping a lot of energy. Typically, spark energy is of the order of 20mJ and you are adding an order of magnitude more. Where does the value of 0.15J come from, experiments?


Thanks,

[magicbretzel]

Hi Nitesh,

Indeed, it is probably too much energy. I tried with less energy and I don't run into these problems anymore. Thank you for your help!