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traveller444
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What effect does rotation have on a sphere moving through a fluid (liguid or gas) when traveling along the axis of rotation? The simplest being an up or down motion.
traveller444 said:Yes, exactly. Like rifling for a bullet or a stabilizing spin for a football. However, I'm wondering more about whether it would affect velocity or general momentum.
Drakkith said:I don't know, but I would guess that it would not unless the spinning somehow caused there to be less friction on the object.
The concept is based on the fluid dynamics principle of Bernoulli's equation, which states that an increase in the speed of a fluid results in a decrease in its pressure. In this case, the spinning sphere creates a lower pressure zone in front of it, causing the fluid to flow towards the back of the sphere and creating a propulsive force that moves the sphere forward.
The faster the sphere rotates, the greater the difference in pressure between the front and back of the sphere, resulting in a stronger propulsive force and faster movement through the fluid. However, if the sphere moves too fast, it can create turbulence and decrease its efficiency.
The efficiency of the sphere's movement is affected by various factors, including the shape and size of the sphere, the viscosity of the fluid, and the speed of rotation. A streamlined shape and slower rotation speed can increase efficiency, while a more viscous fluid can decrease it.
No, a spinning sphere can only travel in the direction of its axis of rotation. The propulsive force generated by the difference in pressure only works in the direction of the axis of rotation, so the sphere cannot move sideways or backwards.
The concept is used in various engineering applications, such as propellers on ships and submarines, turbine blades in power plants, and even in sports equipment like golf balls and tennis balls. It is also studied in aerodynamics and fluid dynamics research to better understand the movement of objects through air and water.