The　fundamental　problem　encountered　in　the　bubbling　fluidized　bed　reactors　is　the　presence　of　multiscale　structures　which　cannot　be　resolved　by　the　conventional　drag　models.　In　this　study,　a　novel　hybrid　Eulerian-Lagrangian　dense　discrete　phase　model　(DDPM)　based　on　energy　minimization　and　multiscale　(EMMS)　drag　is　proposed　for　the　first　time　to　analyze　the　hydrodynamics　of　bubbling　fluidized　bed　reactors　with　Geldart　A,　A/B,　and　B　particles.　By　comprehensive　and　comparative　investigations　of　a　number　of　key　modeling　parameters　(grid　size,　drag　force,　particle　number　per　parcel,　turbulence,　and　particle-particle　restitution　coefficients),　our　proposed　DDPM-EMMS　model　stands　out　of　the　currently-available　counterparts　in　terms　of　improved　grid-independency,　multiscale　structures　resolvability　with　coarser　grids,　better　parcel-independency,　and　better　performance　with　laminar　treatment　against　turbulence.　©　2020　Elsevier　B.V.