Solution of the eigenvalue problem
The eigenvalue problem having up to 200 000 DOF's has to be solved. For this purpouse the Subspace Iteration Method with inverse Cayley transformation is used. The idea of SIM is to replace the large-dimensional problem with the small-dimensional one having the same dynamical properties. The original problem is replaced with the shifted (preconditioned) one :
with
 |
Eigenvalue spectrum for circular cylinder,
Re = 5, before and after Cayley transformation. |
The shift increases convergence and transforms the left-most eigenvalues, for the most amplified modes, into the dominating ones.
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Last modified: Wed Dec 15 11:54:53 CEST 1999
