Reducing the occurrence of volume fractions beyond physical bounds is critical in multiphase numerical simulations. This paper proposes a method for limiting the face flux of volume fractions based on local cell values, aiming at reducing unphysical values. The proposed method is applicable to three-dimensional unstructured meshes and velocity fields that are not divergence-free. To validate the approach, scalar field translation and rotation tests were conducted on unstructured meshes with varying grid resolutions. The proposed flux-limiting method demonstrated increased accuracy, particularly as the grid became coarser. Subsequently, a gravity-driven two-phase separation was simulated using an Euler–Euler multiphase model to evaluate the limiter’s performance under a non-divergence-free velocity field. Compared with the traditional first-order upwind scheme, the proposed method achieved up to an 80% reduction in error.

Bound of Volume Fraction,Flux Limit Method,Multiphase Flow,Numerical Simulation