Abstract: A jet engine having no moving parts includes a toroidal combustion chamber formed in a thickened cylindrical side wall of an engine housing and a toroidal exhaust port that directs exhaust gases radially inwardly and towards an outlet of the engine. The escaping exhaust gases travel at a high velocity and thus induce a secondary air flow through the engine. The entrained secondary air enters the engine inlet, cooling and slowing the exhaust gases. In a second embodiment, the trailing end of the housing is frusto-conical and the exhaust port directs the exhaust gases to converge toward one another so that entrained air also flows in a converging pattern. In a third embodiment, the housings of the first two embodiments are positioned in axial alignment with one another so that converging air entrained by the second housing augments the mass of air entrained by the first.