TY  - EJOU
AU  - Mittal, Sanjay 

TI  - Linear Stability Analysis of Time-Averaged Flow Past a Cylinder
T2  - Computer Modeling in Engineering \& Sciences

PY  - 2008
VL  - 27
IS  - 1&2
SN  - 1526-1506

AB  - Flow past a circular cylinder looses stability at a Reynolds number,<i>Re~47</i>. It has been shown, in the past, that the linear stability analysis (LSA) of the steady state solution can predict not only the critical <i>Re</i>, but also the non-dimensional frequency, <i>St</i>, of the associated instability. For larger <i>Re</i> the non-linear effects become important and the LSA of the steady-state flow does not predict the correct <i>St</i>. It is shown that, in general, the LSA applied to the time-averaged flow can result in useful information regarding its stability. This idea is applied to the <i>Re = 100</i> flow past a circular cylinder. The LSA of the time-averaged flow results in the correct value of <i>St</i>. Proper Orthogonal (POD) or Karhunen-Loéve (K-L) decomposition of the unsteady flow using the snapshot method is also carried out. The modes from this decomposition are compared to the unstable modes computed using the LSA.
KW  - Circular Cylinder
KW  -  Linear Stability Analysis
KW  -  Finite Element Method
KW  -  Reynolds Averaged Navier Stokes Equations
KW  -  Proper Orthogonal Decomposition
KW  -  Karhunen-Loéve (K-L) decomposition

DO  - 10.3970/cmes.2008.027.063