Difference between MFiX and Ansys Fluent

What is basic difference between mfix and fluent? Is mfix better than fluent? Which is one better for multiphase flow and how?

Well, you’re asking on the MFiX forum, so of course we will tell you MFiX is better!!

For a more unbiased view I suggest you do a literature seach. Here’s one relevant paper:
A Comparison of Ansys Fluent and MFiX in Performing CFD-DEM Simulations of a Spouted Bed

“Despite the similarity of the setup, MFiX seems to perform significantly better.”

– Charles