FREQUENCY ANALYSIS OF CENTRIFUGAL FAN IMPELLERS.

The geometric periodicity is utilized to determine the natural frequencies of centrifugal fan impellers. Triangular plate elements having six degrees of freedom are used to model the impellers. Potter's scheme of solving tridiagonal block matrices is extended to the present analysis. The simultaneous iteration scheme is modified to extract the natural frequencies from the resulting complex eigenvalue problem. Analytical results are compared with experimental results.