Proper orthogonal decomposition analysis of vortex dynamics of a circular cylinder under synthetic jet control

Feng, Li-Hao; Wang, Jinjun; Pan, Chong

doi:10.1063/1.3540679

Cited by 184 publications

(70 citation statements)

References 40 publications

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“…It can be shown that combining the u-and v-based POD results leads to the same results as obtained with the velocity-based POD carried out above. This is consistent with Feng et al (2011) who showed that the POD analysis-based one-velocity component only is appropriate for investigating the near wake.…”

Section: Podsupporting

confidence: 92%

“…On the contrary, the velocity-based POD performed in the same flow fields exhibited such a high relative contribution in the most dominant mode (e.g., 30-40 %), showing that the flow is highly organized. In addition, Feng et al (2011) applied both the vorticity-based POD and the velocity-based POD to the wake of a circular cylinder with synthetic jet control and showed that the POD results based on streamwise and vertical velocities are similar to those from the vorticitybased POD for different vortex shedding regimes. It thus seems that the type of POD that is better suited for extracting the dominant structures may depend on the particular flow.…”

Section: Introductionmentioning

confidence: 50%

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Comparison between velocity- and vorticity-based POD methods in a turbulent wake

et al. 2015

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Section: Podsupporting

confidence: 92%

Section: Introductionmentioning

confidence: 50%

Comparison between velocity- and vorticity-based POD methods in a turbulent wake

et al. 2015

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“…The POD, a flow field analysis method, is a tool that is used to overcome this difficulty. Based on this POD and its analysis of the spatiotemporal characteristics [23,27], it will be more effective to extract the coherent vortical structures and understand the mechanism of the unsteady flow control. The POD method is briefly discussed.…”

Section: Flow Field Analysis Methods (Pod)mentioning

confidence: 99%

Research on Pulsed Jet Flow Control without External Energy in a Blade Cascade

Chen

Huang

et al. 2017

Energies

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Abstract:To control the flow separation in the compressors, a novel pulsed jet concept without external energy injection is proposed. The new concept designs a slot in the middle of the blade and sets a micro device to switch the slot periodically. Such a structure is expected to generate a pulsed jet by the pressure difference between the pressure side and the suction side of the blade. In order to analyze the interaction between the pulsed jet and unsteady separated flow, our numerical and experimental study is based on a specific cascade (with a flow separation inside) and a pulsed jet (one of the unsteady flow control method). The experimental and numerical results both show that when the frequency of pulsed jet is approximate to that of the separation vortex, then the control tends to be more effective. Based on the numerical simulations, the proper orthogonal decomposition (POD) is then used to reveal the control mechanism, extracting the different time-space structures from the original field. The results with the aid of POD show that the pulsed jet can redistribute the kinetic energy of each mode, and strengthen or weaken certain modes, particularly, while the steady jet reduces the kinetic energy of high-order modes in whole. Also, pulsed jet with proper parameters can transfer the energy from higher modes to the first flow mode (averaged flow), which is due to the conversion of the spatial vortical structures and the time evolution of the modes.

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“…It is an effective way to extract the dominant structures in turbulent flow based on the turbulent energy rank. Feng [9] used POD method to acquire the vortex dynamics of a circular cylinder controlled by a synthetic jet. The coefficient by POD and corresponding dominant frequency can reveal the characteristics of the flow mode.…”

Section: Introductionmentioning

confidence: 99%

Dynamic Mode Decomposition on LES Result of Cylinder Cascade Wake

Wang¹

2017

Proceedings of the 4th International Conference of Fluid Flow, Heat and Mass Transfer (FFHMT'17)

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-Flow around cylinder cascade is a common flow configuration which can be used in heat transfer and other industries. The interaction of vortices has an unavoidable impact on the downstream. The information of transient flow can be acquired by large eddy simulation(LES). In this paper, the cylinder cascade with the gap ratio of 2.0 was simulated by large eddy simulation method at two Reynolds number conditions and the mode decomposition algorithm was adopted to analyze the movement of vortex. Compared with information extracted by POD algorithm and FFT method, the validation of DMD algorithm was discussed by the results from the hypothetic scalar field and the experimental data. The accuracy of LES results and the characteristic of the vortex were analyzed by DMD algorithm. It has been verified that DMD algorithm can be used for cascade engineering on account of the accurate description of the flow structure.

show abstract

Proper orthogonal decomposition analysis of vortex dynamics of a circular cylinder under synthetic jet control

Cited by 184 publications

References 40 publications

Comparison between velocity- and vorticity-based POD methods in a turbulent wake

Comparison between velocity- and vorticity-based POD methods in a turbulent wake

Research on Pulsed Jet Flow Control without External Energy in a Blade Cascade

Dynamic Mode Decomposition on LES Result of Cylinder Cascade Wake

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