Title: Boundary-layer instability and transition on a flared cone in a Mach 6 quiet wind tunnel

Authors: Jerrod Hofferth; William Saric; Joseph Kuehl; Eduardo Perez; Travis Kocian; Helen Reed

Addresses: Aerospace Engineering, Texas A&M University, 701 H.R. Bright Building, 3141 TAMU, College Station, TX 77843-3141, USA ' Aerospace Engineering, Texas A&M University, 701 H.R. Bright Building, 3141 TAMU, College Station, TX 77843-3141, USA ' Aerospace Engineering, Texas A&M University, 701 H.R. Bright Building, 3141 TAMU, College Station, TX 77843-3141, USA ' Aerospace Engineering, Texas A&M University, 701 H.R. Bright Building, 3141 TAMU, College Station, TX 77843-3141, USA ' Aerospace Engineering, Texas A&M University, 701 H.R. Bright Building, 3141 TAMU, College Station, TX 77843-3141, USA ' Aerospace Engineering, Texas A&M University, 701 H.R. Bright Building, 3141 TAMU, College Station, TX 77843-3141, USA

Abstract: Measurements of boundary-layer transition location and boundary layer profiles on a sharp-tipped 5°-half-angle flared cone were made in a low-disturbance Mach 6 wind tunnel. Uncalibrated boundary-layer profiles of mean and fluctuating voltage representative of mass flux are obtained using constant temperature hot-wire anemometry at several axial locations, and are notionally compared with preliminary simulations. Spectral energy content is observed between 250 and 310 kHz - the first measurements of frequencies typical of the second mode instability at Texas A&M. Growth of this high-frequency content is compared with N-factor results from linear parabolised stability equation (LPSE) computations. Possible sources of disagreement between the experimental and computed frequencies for second-mode growth are discussed, as are future improvements to the hotwire anemometry technique. Nevertheless, the successful measurement of high-frequency content highlighted here constitutes an important step toward acquisition of calibrated measurements of hypersonic boundary-layer instabilities to be used as code validation.

Keywords: hypersonics; quiet wind tunnels; low disturbance; boundary layer stability; laminar turbulent transition; second-mode instabilities; hot wire anemometry; linear stability theory; LST; parabolised stability equations; PSEs; flared cone; spectral energy content; boundary layer instabilities.

DOI: 10.1504/IJESMS.2013.052386

International Journal of Engineering Systems Modelling and Simulation, 2013 Vol.5 No.1/2/3, pp.109 - 124

Available online: 21 Feb 2013 *

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