We assumed that we could get more thrust out of our bilge pumps by adding an optimal nozzle to them. To find that optimal size, we perfomed an experiment using the equipment avalable in the lab.
First, we used the lathe to make a variety of nozzles out of some nylon rod that we ordered.
The bilge pump, along with the support apparatus we made for it to have it thrust as straight down as possible.
The wires used to support the pump.
Bilge pump attached to the digital scale.
The entire experimental setup except for the computer.
A graph of the force against the signal sent to the servo controller for each of the nozzles. The force curves start with the 1/4" nozzle and climb until the peak at the 1/2" nozzle. The Curves then drop back down with the 5/8" and 3/4" nozzles.
The maximum force exerted by the pump with each nozzle graphed against the nozzle diameter. Clearly, this shows now the force peaks with the 1/2" nozzle.
The power used to run the bilge pump versus the signal sent to the servo controller.
Maximum force divided by Power to show that the efficiency also peaks witht the 1/2" nozzle. Clearly, the 1/2" nozzle is the one to go with.