Maximum Power of A Drag Based Wind Turbine
Equation (1) will be the starting point in this derivation. Equation (CD) is used to define the force, and equation (RelativeSpeed) is used for the relative speed. These substitutions give the following formula for power.
-
(DragPower)
The formulas (CP) and (SpeedRatio) are applied to express (DragPower) in nondimensional form:
-
(DragCP)
It can be shown through calculus that equation (DragCP) achieves a maximum at . By inspection one can see that equation (DragPower) will achieve larger values for . In these circumstances, the scalar product in equation (1) makes the result negative. Thus, one can conclude that the maximum power is given by:
Experimentally it has been determined that a large is 1.2, thus the maximum is approximately 0.1778.
Read more about this topic: Wind Turbine Aerodynamics
Famous quotes containing the words maximum, power, drag, based and/or wind:
“Probably the only place where a man can feel really secure is in a maximum security prison, except for the imminent threat of release.”
—Germaine Greer (b. 1939)
“But the life of Spirit is not the life that shrinks from death and keeps itself untouched by devastation, but rather the life that endures it and maintains itself in it. It wins its truth only when, in utter dismemberment, it finds itself.... Spirit is this power only by looking the negative in the face, and tarrying with it. This tarrying with the negative is the magical power that converts it into being. This power is identical with what we earlier called the Subject.”
—Georg Wilhelm Friedrich Hegel (1770–1831)
“Dying smokers sense
Walking towards them through some dappled park
As if on water that unfocused she
No match lit up, nor drag ever brought near....”
—Philip Larkin (1922–1986)
“The time must come, my friend ... when brutality and the lust for power must perish by its own sword.... For when that day comes, the world must begin to look for a new life, and it is our hope that they may find it here. For here we shall be, with their books, and their music, and a way of life based on one simple rule: Be kind.”
—Robert Riskin (1897–1955)
“God tempers the wind to the shorn lamb.”
—Laurence Sterne (1713–1768)