What is the principle of the infinite loop water wheel?
3 Answers
The principle of the infinite loop water wheel utilizes the phenomena generated by gravity and pressure. Definition of a water wheel: A water wheel is an ancient tool for lifting water for irrigation. Also known as a sky wheel, it stands over 10 meters tall and is supported by a 5-meter-long axle with a diameter of 0.5 meters, which holds 24 wooden spokes radiating outward. Function of the water wheel: Each spoke is equipped with a scoop and a bucket at its tip. The scoop collects water, and the bucket holds it. As the river flows, the inertia of the water's movement causes the spokes to rotate slowly, lifting the buckets filled with water step by step. At the top, the buckets naturally tilt, pouring the water into a flume that directs it to the irrigation fields.
When I was a kid, I absolutely loved playing with this miniature water wheel device! Essentially, it utilizes the siphon effect and gravitational potential energy conversion. Water flows from the top reservoir through a thin glass tube to impact the blades, driving the water wheel's rotation. The water collected at the bottom is channeled into a transparent tube, and when the water level exceeds the top elbow of the tube, the siphon effect automatically pumps the water back to the top reservoir. The entire process operates without an electric pump, and the diameter of the glass tube directly affects the water flow rate and the wheel's rotation speed. Reflecting on it now, this little gadget actually embodies several principles of fluid mechanics, such as Bernoulli's equation and capillary action. Replacing the tubes with different diameters allows for observable changes in water flow velocity.
Conducting this experiment yourself reveals that the key lies in the water level difference setup. The top water tank should be approximately 20 centimeters higher than the water wheel, while the depth of the bottom collection trough should be kept within 10 centimeters. The most ingenious part is the U-shaped return pipe—when the water level in the collection trough reaches the apex of the U-shaped pipe, it triggers the siphon phenomenon. Be mindful not to exceed a 5-millimeter diameter for the glass tube, as larger diameters result in insufficient water flow rotational force. On one occasion, I tested with liquids of varying viscosities and discovered that glycerol solution circulates more stably than pure water. Temperature also plays a role; at 25°C, the molecular activity of water molecules is just right to maintain a steady rotation speed of the water wheel.
