solve(fvm::ddt(rho)+fvc::div(phi));Info<<"------Timecost density = "<<tm_density.time_use<<"s-------------------"<<nl<<endl;totaldensitytime+=tm_density.time_use;
Info<<"min/max(Yt after diffusion) = "<<min(Yt).value()<<", "<<max(Yt).value()<<endl;tm_species.stop();Info<<"------Timecost species = "<<tm_species.time_use<<"s-------------------"<<nl<<endl;totalspeciestime+=tm_species.time_use;