Numerical simulations of dense suspensions with a high resolution of the liquid phase (below the particles scale) requires two-way coupling of particle dynamics with stepwise resolution of Navier-Stokes equations for the fluid phase. The Lattice Boltzmann Method (LBM) provides a versatile approach, which has shown its high robustness for the simulation of simple situations such as the free fall of a particle inside a fluid and for the calculation of the permeability of a packing of fixes particles [1,2]. We show here how LBM can be coupled with DEM and parametrised for the simulations of suspensions with several thousands of particles. In particular, we show the differences between the MRT and BGK models for the collision term. Then, we briefly present a parametric study of the effects offluid properties (viscosity, density), particle properties (size, density) and boundary conditions (shear rate, confining pressure) in immersed flows. We show that our results, in terms of effective viscosities of the flow, are in excellent agreement with reported experiments in literature [3].[1] Aidun, C.K. and Clausen, J.R., 2010. Lattice-Boltzmann method for complex flows. Annual review of fluid mechanics, 42, pp.439-472.[2] Mutabaruka, P., Delenne, J.Y., Soga, K. and Radjai, F., 2014. Initiation of immersed granular avalanches. Physical Review E, 89(5), p.052203.[3] Amarsid, L., Delenne, J.Y., Mutabaruka, P., Monerie, Y., Perales, F. and Radjai, F., 2017. Viscoinertial regime of immersed granular flows. Physical Review E, 96(1), p.012901.