2D XY, Symmetry and Axisymmetry cases

Gianfranco

Hello I am modeling a compressible flow. The system is a cylinder attached to a pipe. The pipe allows water to come in and since the cylinder is full of water pressure is created. I have 3 different cases XY case in where it is just a plane, Case 2 = XY in where the center BC is a symmetry and Case 3 = Axisymmetry the axis lies in X direction with the domain in the possitive Y direction. The simulation runs ok in the XY case (case 1), in case 2 the simulation runs ok but after reaching 100 MPa in pressure the solution diverges. Case 3 is impossible to initialize the solution the initial values giving by Fluent are 1.#QNAN. I though using case 3 will simplify my problem from a 3D to 2D. At the inlet the BC is mass flow rate of 0.01 kg/s. Does anyone knows why the case 3 and after some iterations case 2 does not work? I have all the files and I would email them per request. Kind regards Gianfranco