A Combined Experimental - Numerical Approach for Motorcycle Crank Noise: Modeling 2002-01-2209

The crank noise of a motorcycle often spoils the product value because of its annoying sound. Many approaches have been tried to cope with this troublesome issue. In recent years, a CAE-based method has been adopted to evaluate new designs for engines and to propose design changes that determine any identified issue. But it was a challenge to make an accurate CAE model due to the relatively high frequency characteristics of the noise generated by ball bearing-supported crankshafts. This paper presents the virtual modeling of a single-cylinder engine of a motorcycle that succeeds in identifying the mechanism behind the generation of annoying noise. Furthermore, different possible design changes were evaluated in order to determine the issue. A combined experimental and numerical approach was adopted to obtain the necessary accuracy. Experimental data were used to identify important parameters that determine the engine behavior and thus are critical to the modeling of such an engine.