Fig.1

HUST ∅0.5 m Mach number 6 Ludwieg tube wind tunnel［38］

Fig.2

Sharp cone model and distributed roughness elements

Fig. 3

Size of distributed roughness elements

Fig.4

Experimental site of infrared thermography produced by InfraTec company

Fig. 5

PSD results of pressure pulsation at each streamwise station in repeatable experiments

Fig.6

Infrared thermography results at each repeatable experiment

Fig.7

Comparison of PSD results at different distribution positions in cases of smoothness and 25 mm width roughness

Fig.8

Contour of growth rate in smooth cone case along the stream wise direction

Fig.9

Curve of pressure signal cross-correlation number between adjacent PCB measuring points in smoothness case

Table 1

Comparison of instability waves convective velocity in 25 mm width roughness case

Fig.10

Bispectrum analysis results in cases of smoothness and 25 mm width roughness at different streamwise stations

Fig.11

PSD results of sharp cone in 40 mm width roughness case at different distribution positions

Table 2

Comparison of instability waves convective velocity in 40 mm width roughness case

Fig.12

Bispectrum analysis results of 40 mm width roughness cases at different streamwise stations

Fig.13

Comparison of PSD results at PCB1 station in 25 mm and 40 mm width roughness cases

Fig.14

Growth rate of second mode instability waves between PCB1 and PCB2 stations in 25 mm and 40 mm width roughness cases

Fig.15

Comparison of the influence of roughness width at different positions on PSD at PCB1 station

Fig.16

Growth rate of second mode instability waves between PCB1 and PCB2 streamwise stations at different roughness locations

Fig.17

Comparison of infrared thermography results of 25 mm and 40 mm width roughness cases

Table 3

Comparison of infrared measurement results of transition position with PSD results