کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
671016 | 887075 | 2011 | 12 صفحه PDF | دانلود رایگان |
![عکس صفحه اول مقاله: Floquet stability analysis of viscoelastic flow over a cylinder Floquet stability analysis of viscoelastic flow over a cylinder](/preview/png/671016.png)
A Floquet linear stability analysis has been performed on a viscoelastic cylinder wake. The FENE-P model is used to represent the non-Newtonian fluid, and the analysis is done using a modified version of an existing nonlinear code to compute the linearized initial value problem governing the growth of small perturbations in the wake. By measuring instability growth rates over a wide range of disturbance spanwise wavenumbers α, the effects of viscoelasticity were identified and compared directly to Newtonian results.At a Reynolds number of 300, two unstable bands exist over the range 0 ≤ α ≤ 10 for Newtonian flow. For the low α band, associated with the “mode A” wake instability, a monotonic reduction in growth rates is found for increasing polymer extensibility L. For the high α band, associated with the “mode B” instability, first a rise, then a significant decrease to a stable state is found for the instability growth rates as L is increased from L = 10 to L = 30. The mechanism behind this stabilization of both mode A and mode B instabilities is due to the change of the base flow, rather than a direct effect of viscoelasticity on the perturbation.
Journal: Journal of Non-Newtonian Fluid Mechanics - Volume 166, Issue 11, June 2011, Pages 554–565