[siamakkhayyatrostami]

hi
i am trying to model Sediment Scour in Shallow Water in flow-3D, the example of software has this topography component in format of .inp , which contains facet normal and vertexes coordinate in order of "X" "Y" "Z" and even with one cell in z direction software recognizes component finely, i used Topo2STL utility of flow-3d to create my own topography from a "XYZ" grid file which results in facet normal and vertexes coordinate contained .stl file. so far like example, flow 3d can recognizes my component even with one cell in z direction, i define this component as sediment packed, after one time step of simulation my topography is vanishing and water surface is adjusting itself with the floor of my mesh block, ignoring the topography (shallow water mesh block and physic is active). does Sediment Scour in Shallow Water in flow-3D work only with .inp format for component?
(i defined bed load coefficient and entrainment coefficient equal to zero to prevent sediment scour, but it didn't work too and component is ignored)