[denny.rivas]

Hi, I am trying to set a simulation in Flow-3D v10.1 to assess erosion over a natural dam. The bed in front of and surrounding the dam is initially dry. However, results show that despite there is not fluid flow over those areas in the initial time steps, packed sediment is moving and rearranging. Indeed, that movement looks like fluid flow. How is this possible? wrong boundary or initial conditions?

The Upstream boundary condition is "wall" since the fluid source is mass-moment type. The downtream boundary condition is "continuative", and I have a fluid region representing impounded water. The whole domain, except by reservoir water, is comprised of a single-species packed sediment.

What is making the whole packed sediment to flow under no fluid-flow influence?