I ought to study for my thesis heat transfer between ash and air with CFX. For me my problem is that mass flows of ash and air have the same order of magnitude. What is the main difference between eulerian and lagrangian approach? The most important problem at moment is: is there a theoretical limit to the application of lagrangian approach? Is this approach only computational expensive? Is there a limit on diameter of particles I can study with eulerian approach?

Thank you in advance

is there a theoretical limit to the application of lagrangian approach? No, but there are common sense limits.

Is this approach only computational expensive? Yes

Is there a limit on diameter of particles I can study with eulerian approach? No, numerically, but , yes, from common sense.