In present work a results of experimental investigations of stability and transition in hypersonic boundary layers on cones are shown. Measurements of laminar-turbulent transition location were carried out in wind tunnels T-326 (M=6) and AT-303 (M=12) of ITAM SB RAS. Obtained transitional Reynolds numbers are close to flight data. Experimental investigations of natural disturbance and artificial wave packets development in laminar boundary layer were performed on sharp and blunted cones at zero angles. Experiments were carried out at Mach number M=5.92 and unit Reynolds number Re_1=12.5*106 1/m. For natural disturbances exist of second mode disturbances were shown. But these waves did not play sufficient role in laminar-turbulent transition process in our conditions. Wave packets were generated by point glow discharge at frequencies corresponding to most fast growing waves of the first and second modes. It was shown that inclined waves (wave vector inclination angle – 60 deg) are most unstable for first mode, 2d waves (wave vector inclination angle – 0 deg) are most unstable for second mode. Obtained phase velocities and amplification rates for both modes satisfactory agreed with computational data. Results obtained for blunted cones showed that initial levels and amplification rates are strongly dumped by bluntness.
Note. Abstracts are published in author's edition
© 1996-2001, Institute of computational Techologies SB RAS, Novosibirsk
© 1996-2001, Siberian Branch of Russian Academy of Science, Novosibirsk
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