This is a very clever modification, but it wouldn't work without the 2 open flaps at the bottom of the tube, and the fact that the tube makes contact with the bottom of the barrel or is otherwise sealed at the bottom. When you rotate the tube, the flaps direct the flow of corn so that its pushed against the screw as if the screw was rotating. If there really was just a normal tube rotating around the screw, no part of it would apply a force to the corn and the tube would just rotate in the still corn. If you span this tube very fast in a water bucket even without the screw it would act like a normal pump