The effects of controlled excitation on elliptic jets of moderate aspect ratios have been studied via hot-wire measurements and flow-visualization. Like axisymmetric jets, elliptic jets are also found to be characterized by the 'preferred mode' and the 'stable pairing mode'. The jet spread and locations of switching of major and minor axes of the jet cross-section as well as the near-field turbulence characteristics are drastically altered under excitation depending on the frequency and amplitude of excitation. 'Preferred mode' and 'stable pairing mode' coherent structures have been educed through phase-locked hot-wire measurements. The coherent structure dynamics in the near field of an elliptic jet are considerably different from that in the axisymmetric jet.
|State||Published - 1985|