RESONANT INTERACTIONS OF TOLLMIEN-SCHLICHTING WAVES IN THE BOUNDARY LAYER ON A FLAT PLATE

<正> Resonant interaction phenomena of Tollmien-Schlichting waves（T.-S.waves）areexamined experimentally by spectral analysis method.Results demonstrate that,in the spectrameasured in the vicinity of the critical layer of the unstable boundary layer,the energy of T.-S.wavesconcentrates in a narrow band of frequency with one to three peaks in the power spectra correspondingto the eigenfrequencies of T.-S.waves and the frequency with maximum growth rate located betweenthe upper and lower branches of the neutral curve.The resonant interactions,transfer the energy ofthese eigencomponents to their subsequent subharmonics in a range of Rδ* where their growth ratesincrease from zero to a maximum value,and the boundary layer becomes turbulent after the thirdresonant interaction.