Home        Store        Docs        Blog

Efficiency of T100 and T200 thrusters


(Santhosh R) #1

Hi!

Why are your thrusters efficient at 1600 us signal (low speed). 1600 us will also be of low thrust (0.3 kgf in your case). Why didn’t you design it to perform well at higher speeds? is it possible at all?

I also would like to know your motivation for using g/W. I appreciate this measure as it is a quantity that fully qualifies a thruster instead of the vehicle’s drag parameters. Why don’t others also use this.?


(Rusty) #2

Hi Santhosh,

Considering efficiency as “thrust per watt”, propellers are inherently more efficient at lower speeds than at high speeds. At very low speeds the friction within the motor dominates and makes the efficiency lower, which is why the efficiency is lower under 1600 us.

We use grams per Watt because it gives a very good gauge of efficiency in static conditions, which is what an ROV experiences most of the times. Note that this does not represent the efficiency under moving conditions. For instance, when used on a boat, the thrusters see an inflow velocity due to the speed of the boat. That moves the point of highest efficient and decreases efficiency at maximum speed. Most propellers (like airplane propellers) are used in forward-moving conditions like this, so efficiency is shown in different units than thrust/Watt.

-Rusty


(Santhosh R) #3

Great. Thanks for the info.