Effect of the surface roughness of blunt cone forebody on the position of laminar-turbulent transition

Investigation of the influence of a slots depth on disturbances in a hypersonic boundary layer

“…Theoretical and experimental works show that using ultrasonic absorptive coating allows to reduce the intensity of most unstable ultrasonic disturbances (second mode disturbances) in hypersonic boundary layers [3][4][5][6][7][8][9]. Experimental investigations confirm that the ultrasonic absorptive coatings effectiveness depends on its depth [6,7].…”

Effect of wall waves on a transition

“…2, taken from [5]). Spectra show that peak corresponding to the second mode (f = 140, 160 kHz) suppressed.…”

“…The concept of stabilization by wavy wall was confirmed in twodimensional direct numerical simulation [3]. It was noted that naturally occurring undulating surfaces (such as expanded heat shields [4]) do not necessarily lead to a more unstable flow and premature transition, like it happens over roughness surface [5]. These configurations require special consideration of the interaction between instability and inhomogeneities in the mean flow.…”

“…The unit Reynolds number was varied in the interval Re 1 = (7.7-69)×10 6 1/m. The model was the same as in work [5], but made of plastic: a flat plate of length 0.35 m and width 0.2m and thickness of 15 mm. The side and leading edges are beveled from below with the angle of 30 deg for the side edges and 20 deg for the leading edge.…”

The effect of roughness of blunted nose of cone on the development of disturbances and laminar-turbulent transition in a hypersonic boundary layer

“…In the previous work [7] the effect of distributed roughness located on a blunt nose of a conical model on the position of a LTT was investigated. In experiments the roughness was uniformly applied to the entire rounding region of the nose-tip.…”