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A ceramic turbocharger rotor (CTR) for high temperature use has been developed. The features of this rotor are the use of silicon nitride which maintains high mechanical strength up to 1,200 °C and a new joining technique between the ceramic rotor and its metal shaft. The CTR is expected to cope with stoichiometrical mixture burning engines which produce a higher exhaust gas temperature for fuel economy, and the impact resistance of the rotor against foreign object damage (FOD) has been markedly increased, over that of earlier rotors, resulting in higher reliability. This paper describes the development of ceramic turbocharger rotors for high temperature use focusing on the mechanical strength of silicon nitride and the joining of the ceramic rotor and its metal shaft.

A ceramic turbocharger rotor (CTR) for high-temperature use has been developed. The features of this rotor are the use of silicon nitride, which maintains high mechanical strength up to 1200°C, and a new joining technique between the ceramic rotor and its metal shaft. The CTR is expected to cope with stoichiometric mixture burning engines, which produce a higher exhaust gas temperature for fuel economy, and the impact resistance of the rotor against foreign object damage (FOD) has been markedly increased, over that of earlier rotors, resulting in higher reliability. This paper describes the development of ceramic turbocharger rotors for high-temperature use, focusing on the mechanical strength of silicon nitride and the joining of the ceramic rotor and its metal shaft.

A hybrid numerical method, combining finite differences with respect to space and a Laplace transform with respect to time, is proposed to determine the heat transfer in a rotary heat exchanger used as a rotating ceramic regenerator for automotive gas turbines. The temperature distributions of the core and of the working fluids are solved for given boundary and initial conditions of a rotary regenerator using this method. An advantage of the present method is that it can be applied when the core and the working fluids have dissimilar temperature distributions. The temperature change in the ceramic honeycomb core was determined from start up to periodic steady state operation. The heat exchanger effectiveness was obtained for an extruded ceramic core used in automotive gas turbine applications.