The study of the pulsating-flow behavior of small inward radial-flow turbines as used in automotive type turbosuperchargers is of great importance in relation to the mode of operation of such units in conjunction with internal-combustion engines. In complete engine-turbocharger systems detailed analysis of turbine behavior is handicapped by the complex interaction of engine and turbocharger, with resultant interdependence of operating variables. In the present investigation the use of a rotary valve driven at various predetermined speeds and discharging cold air under critical conditions ensures close control of the pressure pulses constituting the turbine-energy input. It has therefore been possible to investigate systematically the influence of the most important parameters, viz., (a) pulse frequency, (b) pulse form, (c) pulse amplitude, (d) pipe length, (e) pipe diameter, and (f) turbine speed.