Re: How do you measure the thrust of a propeller under water?

Hi Sue,

I believe that it would be extremely tricky to measure the thrust of a propellor in water by examining the water velocity. Such measurements would be difficult to make, and could be affected by conditions of the water tank. My understanding is that thrust measurements are made by determining the force necessary to hold the propellor in a stationary position. Devices to measure forces are fairly common, at least in the laboratories of introductory physics courses.