Abstract
The nonlinear mechanisms responsible for the generation of subharmonic fluctuations in a transitioning mixing layer are determined by using polyspectral transfer function techniques. Cross-bispectral analysis is used to identify three-wave couplings, and quadratic transfer functions are measured to determine the spectral transfer of energy due to nonlinear interactions. The concept of interaction potential is used to identify potential pairs of fluctuations which can transfer energy to subharmonic fluctuations. The results show that the initial stage of subharmonic growth docs not seem to be due to nonlinear interactions. In this stage, fluctuations near the subharmonic frequency grow at a rate close to that predicted by linear instability theory. The second stage of subharmonic growth docs seem to be due to a nonlinear three-wave interaction mechanism.
Original language | English |
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DOIs | |
State | Published - 1989 |
Event | AIAA 2nd Shear Flow Conference, 1989 - Tempe, United States Duration: 13 Mar 1989 → 16 Mar 1989 |
Conference
Conference | AIAA 2nd Shear Flow Conference, 1989 |
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Country/Territory | United States |
City | Tempe |
Period | 13/03/89 → 16/03/89 |