터보차져 운전모드에 따른 소음맵 비교

A noise map has been developed for globally analyzing special noises radiating from automotive turbochargers. This map could be obtained by replacing the efficiency with noise data in a compressor performance map. The characteristics of a special noise could be easily understood from it since the noise distribution was shown on their operating area. Turbochargers were generally operated under constant speeds for measuring their performance. This paper compared two additional operation modes to the constant speed for the noise map. First, it was operated for almost constant volumetric flow rates in a compressor. Second, it was done for constant pressure ratios. In addition, it was investigated how the maps would be changed by the different sweeping times of surge-to-choke at the constant speeds, 1/2 and 1/4 times of the reference period.