Experimental Investigation of the Second-Mode Boundary-Layer Instability Over a Flat Plate with a Wavy Wall

Authors

Presenter(s)

Megan Sieve

Comments

2:00-2:20, Kennedy Union 311

Files

Description

This study experimentally investigates the effect of wavy walls on the second-mode boundary-layer instability in the hypersonic regime. The experiments were performed in the Air Force Research Laboratory’s Mach-6 Ludwieg Wind Tunnel on flat-plate test articles. Two different flat-plate test articles were used: a smaller test article used in previous studies and one larger that was constructed for these specific experiments. Findings include the initial test results of the larger test article without a wavy-wall insert and results from three different wavy-wall samples taken using the smaller test article. The initial larger flat plate test results showed that the boundary-layer transition onset behavior varied between the fluctuating surface pressure power spectra measurements and the surface heat-flux measurements. The spectral measurements indicated transition onset upstream of the heat-flux measurements. The wavy-wall test results showed that the wavy-wall inserts shifted the second-mode frequencies lower. Additionally, the higher-amplitude wavy walls provided spectra that indicated a second-mode frequency locking tendency, which was shown to trend well with the freestream unit Reynolds number. Supporting computations indicated good agreement with the frequency-modulating effects of the wavy walls.

Publication Date

4-23-2025

Project Designation

Honors Thesis

Primary Advisor

Taber T. Wanstall

Primary Advisor's Department

Mechanical and Aerospace Engineering

Keywords

Stander Symposium, School of Engineering

Institutional Learning Goals

Scholarship; Practical Wisdom

Recommended Citation

"Experimental Investigation of the Second-Mode Boundary-Layer Instability Over a Flat Plate with a Wavy Wall" (2025). Stander Symposium Projects. 3908.
https://ecommons.udayton.edu/stander_posters/3908