Motor design

I need to optimize brushless electric motor design. It should be high torque and look like the image attached. The amount of copper and iron should be minimized given a target torque. The programmer needs to know topology optimization and be aware of concept of rope-length. The algorithm developed should first be able to optimize rope-length the trefoil knot and borromean rings, and then be extended to the final task of optimizing the motor. The "ropes" does not need to be circular. Programming language doesn't matter.