Role of Time Integration in Computing Transitional Flows Caused by Wall Excitation

Sengupta, Tapan K.; Sathyanarayanan, V. K.; Sriramkrishnan, M.; Mulloth, Akhil

doi:10.1007/s10915-014-9967-1

Cited by 7 publications

(1 citation statement)

References 32 publications

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“…24,25 To cover a wide range of possibilities, a 3D spatio-temporal DNS is used in this work, and the full details of this DNS code have been published. 31,32 Furthermore, a critical study of numerical schemes for transitional boundary layers was presented by Sengupta et al 33,34 Here, we give an outline of the code for application to our specific needs of simulating a wavepacket evolving in a Blasius boundary layer.…”

Section: Computational Methodology a Dns Codementioning

confidence: 99%

Hybrid POD-FFT analysis of nonlinear evolving coherent structures of DNS wavepacket in laminar-turbulent transition

Kang

Yeo

2017

Physics of Fluids

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This paper concerns the study of direct numerical simulation (DNS) data of a wavepacket in laminar turbulent transition in a Blasius boundary layer. The decomposition of this wavepacket into a set of "modes" (a basis that spans an approximate solution space) can be achieved in a wide variety of ways. Two well-known tools are the fast Fourier transform (FFT) and the proper orthogonal decomposition (POD).To synergize the strengths of both methods, a hybrid POD-FFT is pioneered, using the FFT as a tool for interpreting the POD modes. The POD-FFT automatically identifies well-known fundamental, subharmonic and Klebanoff modes in the flow, even though it is blind to the underlying physics. Moreover, the POD-FFT further separates the subharmonic content of the wavepacket into three fairly distinct parts: a positively detuned mode resembling a Lambda-vortex, a Craik-type tuned mode and a Herbert-type positive-negative detuned mode pair, in decreasing order of energy. This distinction is less widely recognized, but it provides a possible explanation for the slightly positively detuned subharmonic mode often observed in previous experiments and simulations. a) mpeyeoks@nus.edu.sg This article may be downloaded for personal use only. Any other use requires prior permission of the author and AIP Publishing. The following article appeared in K. L. Kang and K. S. Yeo, Phys. Fluids 29, 084105 (2017) and may be found at http://dx.

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