Turbocharger's pumping limit measuring method for e.g. motor vehicle, involves repeating measurement operation for set of engine speed/fuel flow values to determine pumping curve points to determine pumping limit of turbocharger

摘要

The method involves fixing a value of engine speed/fuel flow. Air pressures at an inlet and an outlet of a supercharger (2) and an air flow in the supercharger are measured by reducing the air flow until an operating point of the supercharger is unstable. The obtained measurement determines a pumping point curve defined by the air flow at the unstable point and a ratio of air pressures or a compression ratio at the unstable point. A measurement operation is repeated for another set of values to determine another set of pumping curve points to determine a pumping limit of a turbocharger (T-C). An independent claim is also included for a device for measuring a pumping limit of a turbocharger, comprising an air flowmeter.