Analysis of the periodical behavior on an impinging jet interfering with a Couette flow

Abstract

We have studied an impinging jet interfering with a Couette flow by using the numerical simulation, then found that the jet angle toward the Couette main flow affects the heat transport mechanism and the periodical vortex structure. However, this periodicity has been captured by just visual check or basic frequency analysis, thus the qualitative and quantitative discussion is still not enough. In this research, we try applying the phase analysis on the time series of flow velocity with the aim of a more essential understanding of this flow field dynamics. To be specific, we apply Takens’s theorem and the recurrence plot to analyze the attractor or periodic pattern of the main flow direction velocity fluctuation. As a result, we found that there is no attractor when the jet flows opposite to Couette main flow, while there is some limit-cycle or strange attractor when the jet flows same direction as the main flow. Especially, the unique and clear strange attractor is reconstructed only when the jet flows orthogonally to the main flow.