How to get rotating speed if I know power?
hello
I need to get RPM at my axial wing turbine but I know only torque/power
2 Answers
The basic engineering formula that applies to this is :
POWER (W) = TORQUE (N-M) 2πN(rev.sec) in SI units. So if we know the power in watts, the torque in N-M we can transpose this formula into :
POWER / (TORQUE x 2π) = N (rev/sec) and therefore work out the required rotational speed.
As mechanical engineers, this power, torque, revs per second relationship is fundamental mechanical knowledge we should know, if you arn't familiar with this, to be an effective mechanical engineering professional you need to learn it. I have attached a pdf document Problem-2 solution that looks at this power, torque, rev per second relationship in more detail
Torque (lb.in) = 63,025 x Power (HP) / Speed (RPM)
Power (HP) = Torque (lb.in) x Speed (RPM) / 63,025
Torque (N.m) = 9.5488 x Power (kW) / Speed (RPM)
Power (kW) = Torque (N.m) x Speed (RPM) / 9.5488
