[Tinystick]

Hello guys:
Recently, I was working on the evaluation of mixing performance in Y-type reactor by way of simulation.There are two liquid inlets,one solution contains I3-, IO3- and H2BO3-, and the other mainly contains H+ (Villermaux - Dushman competing reaction).If mixing is perfect, only H3BO3 will be produced, if not, I3- will also appear.
Laminar model is used to simulate the interaction of molecular diffusion and chemical reaction.In order to attain convergence quickly, I first turn off the volumetric reaction and product eauqtions,only simulating the flow pattern.When it attains convergence,I turn on the chemical reaction and select all the equations, but the result can't achieve convergence,making me really confused.
Anyone can help me? I'd like to extend my sincere appreciation to you!