modified Faraday disc
the EMF for the Faraday disc is calculated as an integral of (v x B) between the disc axis and its edge. As for uniformly rotating disc v = w x r (Bfield is orthogonal to the disc plane) one gets famous result:
EMF = 1/2 w B R^2 , R  disc radius
However such calculation works only if the integrand (v x B) is curlfree, then the integration does not depends on the contour and the EMF is well defined. But anybody can imagine that instead of solid disc we have a conducting fluid flowing out from the center and rotating. In this case v has radial component, curl(v x B) is nonzero and the integral for EMF depends on the shape of the contour.
So then, what is the actual EMF ?
