Homemade Spinning Motor Describe The Physics Behind This Homemade Motor/fan?

Describe the physics behind this homemade motor/fan? - homemade spinning motor

I have the fan with a 9V battery, engine 1.5, and the owner of a 9V battery. To cut for the propeller fan of the real part of a beverage. I have a site about the physics behind the subjects to write about: What makes the engine, the interactions between the battery and the motor, contact to the battery with the engine running, etc. Please help me describe them?