Fan moment of nertia / force question

[sulbien]

Hey everyone,

This is my first post here and I just had a question seeing if anyone could help me with it. I'm performing an experiment using a fan blades which are attached to a shaft that will be rotating a certain amount of weight which is also attached to the shaft but at a different location along it. The question I have is how would I go about mathematically figuring out what is the maximum amount of mass I can rotate and what speed it can rotate at? I'm assuming about a 7mph wind speed pushing on the fan with the fan size being about 2 inches. The shaft size can be variable. Any extra information that is needed I will provide. Thank you so much.

 

[AndyW]

Hello,

Thank you for reaching out to the forum for assistance with your experiment. I would recommend using the principles of torque and rotational motion to determine the maximum amount of mass that can be rotated at a given speed.

First, you will need to calculate the torque produced by the fan blades. This can be done by multiplying the force exerted by the fan blades (in this case, the wind speed of 7mph) by the distance from the center of rotation to the point where the force is applied (the radius of the fan blades).

Next, you will need to calculate the moment of inertia of the rotating mass. This is a measure of an object's resistance to changes in its rotational motion and is dependent on the mass and distribution of the mass along the shaft. The larger the moment of inertia, the more difficult it will be to rotate the mass.

Once you have determined the torque and moment of inertia, you can use the equation T=I*alpha, where T is the torque, I is the moment of inertia, and alpha is the angular acceleration, to calculate the maximum amount of mass that can be rotated at a given speed.

Keep in mind that there may be other factors at play, such as air resistance and the strength of the materials used for the fan blades and shaft. These may also need to be taken into consideration in your calculations.

I hope this helps and good luck with your experiment! If you need any further assistance, please don't hesitate to ask.