Host: The Japan Society of Mechanical Engineers
Name : Dynamics and Design Conference 2018
Date : August 28, 2018 - August 31, 2018
In the mechanical design of an impeller for an automotive turbo-charger, it is pointed out that the mistuning effect caused by the difference of the casting condition should be considered. Namely, the difference of the casting condition causes the small variation of Young’s modulus of each blade on an impeller. These small variations break the cyclic symmetry, and split the eigenvalue pairs. In the forced response of a mistuned impeller, the responses of all the blades become different, and the response of a certain blade may become extremely large due to splitting of the duplicated eigenvalues and distortion of the vibration modes. In this study, the reduced order model FMM (Fundamental Mistuning Model) is applied to evaluate the resonant response of mistuned impeller. First, the frequency response analysis of mistuned impellers is carried out, using both of the FMM and the direct FEA, and the calculated results are compared to confirm the validity of the FMM. Second, the frequency response analysis of mistuned impellers is carried out using the FMM, the Monte Carlo simulation and the optimal method, to examine the effect of various parameters on the maximum response of a mistuned impeller. In addition, the effect of the intentional mistuning on the reduction of the maximum response is researched in detail using the genetic algorithm.
