: Resonators on the charged air side of combustion engines - solutions to prevent disturbing noise generated by resonators

Resonators used on the charged air side of turbo charged engines work in a frequency range between 1500 up to 8000 Hz (occasionally higher). They are introduced to reduce the noise inherent in the air flow. The typical challenges for such parts are the high frequency range, the rapid flow speed, and the pressure inside the ducts. Under such conditions resonators may not only reduce the noise, but unfortunately can also cause disturbing noise through the flow of the air passing the slots of a resonator. As worldwide leading company for the development and the production of such parts, Umfotec has heavily investigated the origin of this disturbing noise through numerical simulation and test stand investigations. With the capability to predict the generation of this disturbing noise via simulations, patented solutions could be derived and the effectiveness shown on test stands. Since now some few publications concerning the generation disturbing noise through air flow are known. Most of them in field of exhaust systems. The author doesn't know any publication for resonators on the charged air side in which this problem is solved at its origin. Most of the publications are showing the interaction of system resonances and aero-acoustic phenomena. Furthermore, there is no commercial simulation tool known with which a precise prediction of such aero acoustic phenomena is available for with small computational costs and time. The author will show in this contribution that via inter action of simulation and test stand measurements a precise prediction of origin of disturbing noise is possible. For this the virtual-Multi-Channel Technic is used with which the determination of interrelations by measurement and calculation becomes possible. General market solutions will be evaluated and improvements demonstrated. Also a solution will be shown with which the origins of areo-acoustic phenomena are prevented while the acoustic performance is remained.