Challenges in the design of radial turbines for small gasoline engines

The modern trends in automotive turbocharger applications are towards the boosting of smaller internal combustion engines in passenger cars. The use of turbochargers in gasoline engines is increasingly common. There are particular issues relating to gasoline engines that result in the aerodynamic efficiency of the turbine design being less than the achievable. The turbine must be designed to provide the best compromise between engine efficiency and transient response. This paper explains the reasons for compromise in the design and presents an example of a design methodology by which a design optimum may be developed.