Hello, developers.
I performed calculations for a chemical reaction case using mfix-23.3.2 and mfix-22.4.3, respectively. In the first scenario (mfix-23.3.2), there is a chemical reaction rate in the monitoring data, but the chemical reaction is not substantially carried out, and the solid mass and components do not change at all; in the second scenario (mfix-22.4.3), the calculation is correct. Please verify this.
pickedbed_2023-12-12T170116.513783.zip (3.8 MB)
When will mfix-23.4 be released, thanks！
Hello, is it convenient to add a contact information?
Thanks for the report. We will double check the reaction code.
MFiX 23.4 will be released before the end of the year.
of course, my QQ:781585020
I’m sorry, I couldn’t find the account you provided. You can add my QQ: 641929223
Something has definitely changed between MFiX versions 22.4.3 and 23.3.2. I am not sure if this is a bug.
With 22.4.3:
(mfix-22.4.3)$ cut -d, -f 8,9,10 < PARTICLE-AVERAGE.csv
#
# Run type: NEW
"x_p(1)","x_p(2)","RRates_RX1"
0.99000000 , 0.0000000 , 0.0000000
0.98994414 , 0.55681454E-04, 0.30000000E-09
0.98988926 , 0.11038650E-03, 0.30000000E-09
0.98983255 , 0.16691443E-03, 0.30000000E-09
0.98977971 , 0.21958674E-03, 0.30000000E-09
0.98972551 , 0.27361148E-03, 0.30000000E-09
0.98967022 , 0.32871865E-03, 0.30000000E-09
0.98961602 , 0.38274718E-03, 0.30000000E-09
0.98956344 , 0.43515665E-03, 0.30000000E-09
0.98950924 , 0.48918888E-03, 0.30000000E-09
0.98945395 , 0.54430368E-03, 0.30000000E-09
With 23.3.2:
(mfix-23.3.2) $ cut -d, -f 8,9,10 < PARTICLE-AVERAGE.csv
#
# Run type: NEW
"x_p(1)","x_p(2)","RRates_RX1"
0.99000000 , 0.0000000 , 0.0000000
0.99000000 , 0.0000000 , 0.30000000E-09
0.99000000 , 0.0000000 , 0.30000000E-09
0.99000000 , 0.0000000 , 0.30000000E-09
0.99000000 , 0.0000000 , 0.30000000E-09
0.99000000 , 0.0000000 , 0.30000000E-09
0.99000000 , 0.0000000 , 0.30000000E-09
0.99000000 , 0.0000000 , 0.30000000E-09
0.99000000 , 0.0000000 , 0.30000000E-09
0.99000000 , 0.0000000 , 0.30000000E-09
0.99000000 , 0.0000000 , 0.30000000E-09
Despite a nonzero reaction rate, the mass fractions for the reactants is unchanged.
I’m investigating further to see exactly when this behavior changed.
– Charles
Please set STIFF_CHEM_MIN_RATE to a very small value. I tried with 1E-25 and it seems to help. This keyword is not exposed in the GUI (it will be in 23.4 release). You can either edit the .mfx file outside the GUI, and add
STIFF_CHEM_MIN_RATE = 1.0E-25
or go to the Advanced pane in the GUI. Make sure you click on the tiny lock icon next to “Update key” to unlock the keyword.
1 Like