A high-altitude balloon team I am on is working on assessing wether or not a small AC motor with a fan is capable of generating electricity sufficient enough to power a payload. Since this our first test of the system, we will only be gathering data to test it’s feasability for future operations.
We will be reading voltage, current and power, amount other things like altitude. Everything is nearly ready to go except one thing: calculating the rotational velocity of the motor/fan.
So my question is: how does one, given voltage, current, power and altitude, calculate the RPM of an AC motor? Is it even doable?