Some guidelines for the experimental characterization of turbocharger compressors

While performance and efficiency measurements of turbocharger compressors are common and standardized, a comprehensive published investigation of uncertainties and repeatability is quite rare. This might be on the one hand due to individual in-house experimental developments and experiences but on the other hand caused by the great number of influencing factors. Therefore, the aim of this paper is to provide a comprehensive structured study of a variety of uncertainty sources gained at the turbocharger test facilities at Technische Universität Darmstadt. The test facilities have been set up with the focus on turbocharger compressor investigations and a great variety of compressor configurations have been investigated during the last years. The investigations showed, that the efficiency uncertainty is dominated by the uncertainty in the temperature measurement. The efficiency uncertainty decreases with increasing wheel speed and total pressure ratio.