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| 21. |
The effect of wall compliance on inflexion point instability in boundary layers |
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Physics of Fluids,
Volume 9,
Issue 2,
1997,
Page 468-470
Alison J. Cooper,
Peter W. Carpenter,
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摘要:
A study into the effects of wall compliance on boundary layer flow in an adverse pressure gradient has been undertaken. The two-dimensional flow given by a Falkner–Skan profile was considered where a powerfulinviscidinstability mechanism occurs as a result of a point of inflexion in the boundary layer profile. Results are presented for two cases: (a) a purely inviscid calculation where the compliant wall is modelled as a thin plate supported by a spring foundation, (b) a double-layer viscoelastic wall model with viscous effects retained. Wall parameters which ensure the absence of hydroelastic instability were used and found to produce growth rate reductions in excess of50&percent;of the corresponding rigid wall values. ©1997 American Institute of Physics.
ISSN:1070-6631
DOI:10.1063/1.869141
出版商:AIP
年代:1997
数据来源: AIP
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| 22. |
A logarithmic 3dEuler inequality |
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Physics of Fluids,
Volume 9,
Issue 2,
1997,
Page 471-472
J. D. Gibbon,
J. Gibbons,
M. Heritage,
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摘要:
The magnitude of the vorticity&ohgr;=|&ohgr;|for the3dincompressible Euler equations on the domain&OHgr;=[0,L]3with boundary conditionsun|∂&OHgr;=0is shown to satisfy the inequality‖log&ohgr;(t)‖2−‖log&ohgr;(0)‖2⩽∫0t‖&ohgr;(&tgr;)‖2 d&tgr;,for smooth initial data with no zeros in&ohgr;. The notation is‖&ohgr;‖22=∫&OHgr;&ohgr;2dVandtis time. The case when initial data have zeros in&ohgr;is also discussed. ©1997 American Institute of Physics.
ISSN:1070-6631
DOI:10.1063/1.869142
出版商:AIP
年代:1997
数据来源: AIP
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| 23. |
Galilean invariance and filtering dependence of near-wall grid-scale/subgrid-scale interactions in large-eddy simulation |
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Physics of Fluids,
Volume 9,
Issue 2,
1997,
Page 473-475
Carlos Ha¨rtel,
Leonhard Kleiser,
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摘要:
A numerical study is presented which was conducted to examine how the average transfer of kinetic energy between large and small turbulent scales in the near-wall flow depends on the filter function. In contrast to some previous findings of other authors, the present analysis reveals that these interactions are qualitatively almost independent of the type of filter employed. It is shown that conclusive results for the individual subgrid-stress components (Leonard stresses, cross stresses, and Reynolds stresses) can only be obtained if a Galilean-invariant form of these components is used. ©1997 American Institute of Physics.
ISSN:1070-6631
DOI:10.1063/1.869143
出版商:AIP
年代:1997
数据来源: AIP
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