KNOWN ISSUE: Mass Arrhenius rate option for particles only correct for 1st order reactions (Class 3 Error)
If a particle reaction is used where the order of the reaction is greater than unity, and the Mass Arrhenius option is selected, then the CFX-Solver calculates the wrong reaction rate. The degree of error is problem specific, and in many situations the error may not be easily noticed.
The problem is due to a bug in the CFX-Solver. For the Mass Arrhenius option the solver calculates the rate of the particle reaction based on particle component mass and not (as it should) on particle component mass concentration i.e. (mass of particle component)/(particle volume).
No workaround is currently available.
ANSYS CFX Release 13.0. A custom executable for ANSYS CFX Release 12.1 is available on request.