The present invention comprises a heat source wherein a vaned rotor (2) is rotatably supported within a cavity (18) formed in a casing (16). Inlet (42) and outlet (54) ports in the casing (16) respectively conduct heat transfer fluid to and from the cavity (18). Heat is generated by blocking the inlet (42) and outlet (54) ports while rotating the vaned rotor (2) to impart mechanical energy of motion to heat transfer fluid contained within the cavity (18). Frictional forces subsequently developed between layers of rotating fluid particles serve to convert essentially all of the mechanical energy of motion of the fluid particles into heat. After the heat transfer fluid reaches a predetermined temperature, the rotation of the vaned rotor (2) is stopped and the inlet (42) and outlet (54) ports are unblocked, thereby enabling the conduction of hot heat transfer fluid to a remote heat transfer surface (116). An electrical control circuit (C) governs the sequencing of the heat generating and transfer cycles.
