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Probing horizontal convection instability via perturbation of the forcing boundary layer using a synthetic jet
| Content Provider | Semantic Scholar |
|---|---|
| Author | Leigh, M. A. M. S. Tsai, Tzekih Sheard, Gregory J. |
| Copyright Year | 2016 |
| Abstract | Horizontal convection driven by a linear temperature profile along the bottom of a two-dimensional rectangular enclosure is perturbed by a small tuned synthetic (zero-net-mass-flux/ZNMF) jet. The jet permits instability in the horizontal convection boundary layer to be investigated in a controlled manner. At a Prandtl number Pr 1⁄4 6.14 and Rayleigh number Ra 1⁄4 2.5 108, slightly below the natural onset of instability, the boundary layer is found to be convectively unstable, exhibiting a disturbance pattern consistent with a RayleigheB enard mechanism. Advection of the boundary layer disturbance gives rise to unsteadiness in the vertical end-wall plume. Nusselt number is enhanced across a range of frequencies for all perturbation amplitudes, with the response dominated by two frequencies differing by approximately a factor of two: each invokes the periodic shedding of vorticity into the vertical end-wall plume at the higher frequency. This suggests that there exists a natural sensitivity in this flow to disturbances convecting in the upstream boundary layer. That is, a convective instability in the horizontal convection boundary layer serves as a disturbance amplifier, with the end-wall plume controlling the frequency of the resulting instability mode. The increase in Nusselt number achieved by a jet with peak speed of the same order as the horizontal convective velocity in the unperturbed flow is consistent with a greater than two-fold increase in Rayleigh number. © 2016 Elsevier Masson SAS. All rights reserved. |
| File Format | PDF HTM / HTML |
| Alternate Webpage(s) | http://sheardlab.org/assets/LeighTsaiHussam_IJTS2016.pdf |
| Language | English |
| Access Restriction | Open |
| Subject Keyword | Amplifier Arabic numeral 0 Control theory Convection Dominator (graph theory) Embedded system Embedding Emergence Enclosure Device Component Ephrin Type-B Receptor 1, human Excitation Excite Exhibits as Topic Instability Large License MATCHING Onset (audio) Perturbation function Perturbation theory Plume (fluid dynamics) Rayleigh–Ritz method SAS Synthetic data Synthetic intelligence Unstable Medical Device Problem Velocity (software development) |
| Content Type | Text |
| Resource Type | Article |
