I am simulating the spray injection process in a GDI engine. I want to calculate the equivalence ratio of the fuel air mixture in the vicinity of spark plug(represented by cell) by calculating the simulated fuel-air ratio divided by the stoichiometric fuel air ratio(0.0666). Please help me on how to calculate the simulated( as it is availble in the run case) fuel -air ratio inside a cell.

Thank you in advance

You can use the operate command to calculate the equivalence ratio. Unfortunately Star-CD can only give you the mass fractions of your species, so you have to calculate the molar fractions yourself. You get the ratio of the molar fractions x1/x2 by (xm1/M1)/(xm2/M2), where xm is the mass fraction and M is the molar weight. Make sure your calculated ratio is in post register 4 to visualise it.

Good luck!