Electric power from vertical-axis wind turbines

Nomenclature a = interference factor aD = downstream interference factor av = upstream interference factor A = actuator disk area & = blade aspect ratio C = blade chord CD = drag coefficient CL = lift coefficient Cn = sine response coefficient Cp = power coefficient based on wind speed CPm = maximum power coefficient based on wind speed CR = chord-to-radius ratio [ C] = Coriolis matrix Dn = cosine response coefficient F = streamwise force on actuator disk Fa = vibratory aerodynamic forces Fa = steady aerodynamic forces Fc = centrifugal forces Fg = gravitational forces K = tip speed ratio at which Kpmax occurs Kp = power coefficient based on rotor speed Kpmsx = maximum power coefficient based on rotor speed [K] = stiffness matrix m =mass flow rate through turbine M = tip speed ratio at which CPm occurs [M] = mass matrix rms = root-mean-square response R = radius of rotor [S] = softening matrix u = structural deflection U streamwise velocity at actuator disk UD = downstream disk velocity Ufj = upstream disk velocity UR = relative fluid velocity in plane of airfoil section Uw = wind velocity in far wake UWD = downstream wake velocity 'wu