Hey guys, I'm actually working on a project of gravitational vortex turbine at an undergrad level. I need to know the energy or the energy required to make a stable free vortex in a cylinder. The cylinder is of 1 m height and 1.5 m diameter. A channel of 0.5 m width is connected to the cylinder. The flow enters into the cylinder tangentially and leaves through an orifice at the bottom of 0.1 m diameter. Any help would be appreciated. Thanks.