As the temperature of the air compressed by turbocharger becomes very high, it sometimes causes problems in combustion such as engine knocking or pre-ignition. Therefore, in order to prevent deterioration of engine performance, intercooler is used to cool the compressed air for turbocharged engine.

To overcome such a problem, new compressor which has dual water-cooling passage is developed. Not only can it reduce the size of the inter-cooler, but it can also improve the compressor pressure ratio at low flow rate condition, and prevent deposit formation. In this paper, we discuss internal flow analysis and experimental test of the compressor. In the future, we are planning to carry out further development for actual application.