Equations Flashcards
Power extracted from wind
Pwind = 1/2 npAV^3
Power delivered from the turbine
Pd = 16/27 1/2 npAV^3
power density
Pw’’ = 1/2 pV^3
available power density
16/27 1/2 pV^3
specific rated capacity or rotor loading
= The rated generated power/the swept area of the turbine
Flux
Φ = nv
total flow across an area
Φ(extra bar) = ΦA
density =
p = mn
dynamic pressure
Wd = 1/2 nmV^2 = 1/2 pV^2
simplistic flow pattern
2mv nv = 2pV^2
realistic flow pattern
P=1/2pV^2 Cd
rankine froude theorem
Cd = Change in P times A
what does the chnage in pressure equal to for Rankine froude theorem
Change in P = 1/2p(v1^2 - V3^2) = Force on the disk
solidity
S = NAp/Av
wake rotation loss
Pg = Yw
tip speed ratio
Lambda = wR/V1
power in the wind by using power dnesity
Pw = Pw’‘A
available power using power density
PA = PA’‘A
energy of a photon
E = hf
frequncy
f = c/lambda
air mass AM =
l/h = 1/cos(x)
fill factor = (Vmp Imp)/(Voc Isc)
= (Vmp Imp)/(Voc Isc)
efficiency of solar
poer out/ Power in = generated P/ 1000W/m^2 * area
heat transfer
Ein - Eout = mcv(T2-T1)
conduction
Qcond = -KA (T2 - T1)/(X2 - X1)
T ist law
= E2 - E1 = Q - W
Wnet,out
Qin - Qout
Thermal efficiency = n =
Wnet,out/Qin
