Abstract
Boundary-layer disturbances on a cone in a hypersonic flow are investigated by heat flux sensors. The cone has a half-angle of 10.9 deg and is situated with a 0 deg angle of attack in a Mach 10 region of a conical nozzle in a shock-tunnel facility. There are three atomic layer thermopile heat flux sensors mounted at different chordwise positions in order to investigate the receptivity to freestream disturbances and the emergence of unstable modes of the boundary layer, that is, Mack first and second modes. The cone’s nose is exchangeable, and there are three differently sized radii to investigate the bluntness effect on transition with respect to entropy/boundary-layer displacement. It is found that each nose type tested shows a different set of amplified spectral bands in the receptivity region of the first two sensors, as well as at the third sensor’s location downstream of the critical point. There is a unique wavelength, scaling with boundary-layer height, that is most receptive to disturbances. For the two sharper cones, this excitation lies in the range of Mack second modes, which are observed in the unstable region. For the blunter cone, this excitation lies near the first mode frequency; as a result, only first modes are amplified and detected at sensor 3, although linear stability theory predicts higher growth rates for second modes.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
