다운사이징 GDI엔진에서 TiAl 터빈휠 터보차저의 적용에 따른 성능 특성

다국어 초록 (Multilingual Abstract)

In this study, steady and transient tests in a multi-cylinder engine were carried out to investigate performance of turbocharger equipped with TiAl alloy turbine wheel. TiAl alloy has low rotational inertia compared to Inconel 718 alloy, conventional turbine wheel material. In the result of the engine experiment, the boost pressure and turbocharger speed started to increase at 12 bar BMEP. In addition, the turbine wheel faced under pulsating flow condition even in steady engine operation condition. The compressor total-to-total pressure ratio of TiAl turbocharger was higher under wide open throttle condition due to low inertia of TiAl turbine wheel. The efficiency of TiAl turbocharger was also higher than that of Inconel 718 turbocharger. In the transient test, time for boost pressure build-up of TiAl turbocharger was shorter than that of Inconel 718 turbocharger, and turbocharger speed of TiAl turbocharger was also higher. However, even though time for pick engine torque was shorter in case of TiAl turbocharger, the pick engine torque of Inconel 718 turbocharger was higher.