Is 1800 Newton meters enough torque to generate 1.5 kilowatts of power?

[Tony Singh]

Homework Statement

The problem is i am not sure if i am right with my calculation please check

Relevant Equations

3 motors with propellers thrust force = 40 Newton meter(NM)
39= 13 Nm each motor, times 3 (13 X 3 = 39)
The turbine blade or the lever arm 3 meters that is the radius fro the rotor or axis
Multiply (Force 40 NM times distance 3 m equals torque 120 NM gearbox input shaft
Torque 120 NM at 120 revolution per minute (RPM) goes into the gearbox at ratio of 1-15 to get output gearbox shaft torque multiply 120 NM with ratio 15 equals (1800 NM at 1800 RPM) = (120 rpm X 15) Is good for 1.5 kilowatt generator with 100% efficiency

i am working on new project so i could use your help.
Please and Thank you
Tony

 

[jbriggs444]

You've quoted a lot of numbers. It is not clear which ones go with which other ones.

It appears that the input is a torque of 120 Newton-meters at 120 revolutions per minute. [If you were trying to calculate this, I could not follow the calculation -- it did not make sense to me].

We have a 15 to one gearbox. You seem to think that this gearbox will both multiply torque by fifteen and multiply rotation rate by fifteen. It does not work that way. If you multiply torque by some factor in a gearbox, you divide the rotation rate by the same factor.

 

[David Lewis]

3 motors with propellers thrust force = 40 Newton meter(NM)

Thrust is measured in Newtons.
Torque is in Newton-meters.

 

[CWatters]

Can you provide a sketch diagram of the system.

 

[Dr.D]

You have provided a torque, but no speed. The information is incomplete because we don't know how much power is available.