Surge Definitions for Radial Compressors in Automotive Turbochargers

A standardized measurement setup and definition of compressor surge is yet to be established in the automotive community. As a consequence, compressor comparisons with regards to compressor operating map width is practically impossible today. This paper presents a possible solution to the described problem by presenting a suitable instrumentation and a correlation between measured values and actual NVH limits normally encountered in turbocharged vehicle applications. The work has been performed in laboratory conditions in a compressor test rig with both steady and pulsating flow as well as in a gas stand with steady flow. The test rig design, measurement setup and error sources are described. Some effects of different boundary conditions to the compressor and how they affect the measurement method are also presented. The definitions and viability of the described methods have been validated through vehicle tests to ensure the possibility of application not only in lab environment but also in actual field use.