Hello, I have some problems with the PRENEK tool. I would like to simulate the flow past a sphere with NEK5000. But I have some problems to set up this case with PRENEK. When I defined a straight open-channel with some element (lets say Nx * Ny * Nz = 2 * 2 * 4, whereas x is the transverse, y the vertical and z the flow direction). To put a sphere into the channel, I'm using the CURVE SIDES > SPHERICAL MESH tool. I'm typing the following w (whole sphere) 0 1 2 (coordinates of sphere center) ("center of the channel") n (no prolate spheroid) s (spherical shell) 0.5 (radius) c (extend to cartesian box) 1.0 (minimal distance to box) Then I'm defining the elements of the sphere as "Wall", but I also have to define all the sides of the cartesian box... And how should I do this, because this box just should be a part of the channel... Thanking you in anticipation.. Best regards, Fred