Turbine power - theory?
Turbine power - theory?
(OP)
Hi,
Can anyone help and explain in 'laymans terms' why the power delivered to a turbine is proportional to: -
i) the density of a fluid, and
ii) the cube of the speed of a fluid.
My question application is related to hydro-electric power generation.
Many thanks
cctdiag
Can anyone help and explain in 'laymans terms' why the power delivered to a turbine is proportional to: -
i) the density of a fluid, and
ii) the cube of the speed of a fluid.
My question application is related to hydro-electric power generation.
Many thanks
cctdiag





RE: Turbine power - theory?
How fast are you dropping them (kinetic energy/speed)
total energy=potential energy + kinetic energy
RE: Turbine power - theory?
To get power, multiply this energy term by the mass flowrate of liquid thru the turbine, and get:
KW= c*rho*V^3 , where c is some proportional constant.
RE: Turbine power - theory?
I have a short discussion on work here:
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Basically, without getting into nitpicking details, work is force times distance. Speed is distance over time. Power is work over time. Putting all that together (using a little algebra I guess), you get that power is force times speed.
Drag force is proportional to the square of the speed, and therefore, power is proportional to the square of the speed, times the force, times the speed, which lends to power being proportional to the cube of the speed.
I honestly don't remember the derivation of why drag is proportional the square of speed, but the units check out. Sorry.