Effects of particle inertia on turbulent channel flow in dense suspensions

Dense suspensions of finite-size particles exhibit strongly heterogeneous modulation of wall-bounded turbulence. Using interface-resolved Direct Numerical Simulations over a wide range of particle inertia, we show that low-inertia particles homogenize near-wall flow topology and restore a symmetric tear-drop structure in the Q--R plane, whereas high-inertia particles generate asymmetric wake-driven topology, suppress Reynolds stresses, and reorganize the momentum and energy budgets. These results establish a clear physical link between particle-migration-induced flow topology and the regional modulation of turbulence in dense suspensions.