Spatiotemporal spectral analysis of a forced cylinder wake

Spatiotemporal spectral analysis of a forced cylinder wake.

The wake of a circular cylinder performing rotary oscillations is studied using hydrodynamic tunnel experiments at Re=100. Two-dimensional particle image velocimetry on the midplane perpendicular to the axis of a cylinder is used to characterize the spatial development of the flow and its stability properties. The lock-in phenomenon that determines the boundaries between regions of the forcing ...

Stability and Bifurcation Analysis of a Forced Cylinder Wake

We present a study on the dynamics of a cylinder wake subjected to forced excitation. Williams et al. (1992) discovered that the spatial symmetry of the excitation plays a crucial role in determining the resulting wake dynamics. Reflection-symmetric forcing was found to affect the Karman wake much more strongly compared to 2 ( , ) Z κ π asymmetric forcing. For low forcing amplitudes, the existe...

Lagrangian and spectral analysis of the forced flow past a circular cylinder using pulsed tangential jets

On Spatiotemporal Spectral Analysis

The wavenumber-frequency spectrum reveals dynamic features of spatiotemporal processes such as traveling oscillatory components, turbulent structures, and linear transfer functions. It can be used to estimate multidimensional covariance, or to directly perform parameter estimation with reduced computational cost. However, simple extensions of univariate spectral estimators can be shown to have ...

Confined three-dimensional stability analysis of the cylinder wake.

A spatially confined stability analysis is reported for the cylinder wake at Reynolds numbers 190 and 260. The two three-dimensional instabilities at these Reynolds numbers are shown to be driven by the flow just behind the cylinder.