This is my concept of a flying saucer's propulsion system. This is a shaftless turbine fan. The fan hovers sandwiched at the axis extreme between an opposing magnetic system, which provides frictionless bearing support. The fan then is powered by the same motor launching system used in electronic rail guns. In a typical fan, the shaft and the fan blade area nearest the axis provides little or no usage of usable power at all, except to add additional weight and drag. Much of the pulling and pushing power on any fan system is provided by the area of the fan farthest away from the central rotating axis. With this design, the center area is free space to be occupied by the powering system and the operating crew.
Counter rotating the effects of torque would be an additional opposing magnetic flux. All of which is computer controlled.
This engine can also be adopted as a replacement for turbofan jet engine systems. There would be no central shaft, with the possibility of utilizing this void for the benefit of a ram jet add on.