A generator (10) of similar construction to a Tesla turbine has a rotor (12) whose working surfaces are formed by a number of interleaving conical laminas of plastic (16) on a central axis (13) free to rotate within a cylindrical housing (11) whose periphery is comprised of hinged vertical louvres (20a). The rotor (12) is connected to a generator (24) by the shaft (13) and the conical laminas (16) as positioned by the torque transmission disc (14), coupling stems (26) and spacers (not shown). Fluid inflow (33) which may be air or water enters via the appropriate louvres and viscous drag over the conical surfaces propels the rotor (12) as the fluid (33) turns through 90 deg. and exits via the centre (28).
