摘要：

The simultaneous generation of phase-coupled plane TS waves and oblique waves with respective wave numbers (α 1 , 0) and (α 2 , β 1 ), (α 2 , β 2 ) are used to study the growth of three-dimensional disturbances in a Blasius boundary layer. This was accomplished using a computer controlled array of line heaters to produce time periodic, spanwise-phase-varying velocity perturbations. Conditions for subharmonic resonance with a TS mode (α,0) and symmetric oblique modes (α/2,+ β ) and (α/2, β )have been fully documented for different streamwise and spanwise wave numbers. Of special interest was the growth of higher harmonic modes including (3/2α, ± β ), (5/2α, ±2 β ), (α,±2 β ) and (0, ±2 β ). Contrasted with these are nonlinear interactions produced by initial nonfundamental/subharmonic modes. Comparisons point to the role of detuned modes as a mechanism for energy saturation and spectral filling associated with laminar-to-turbulent transition.

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