DNS of a compressible boundary layer flow past an isolated three-dimensional hump in a high-speed subsonic regime

D. de Grazia, D. Moxey, S. J. Sherwin, M. A. Kravtsova, A. I. Ruban

Phys. Rev. Fluids, vol. 3, pp. 024101 (2018)

@article{degrazia-2016,
  title = {DNS of a compressible boundary layer flow past an isolated three-dimensional hump in a high-speed subsonic regime},
  author = {de Grazia, D. and Moxey, D. and Sherwin, S. J. and Kravtsova, M. A. and Ruban, A. I.},
  journal = prf,
  volume = {3},
  pages = {024101},
  year = {2018},
  doi = {10.1103/PhysRevFluids.3.024101},
  url = {https://davidmoxey.uk/assets/pubs/2018-prf.pdf},
  abstract = {In this paper we study the boundary-layer separation produced in a high-speed subsonic boundary layer by a small wall roughness. Specifically, we present a direct numerical simulation (DNS) of a two-dimensional boundary-layer flow over a flat plate encountering a three-dimensional Gaussian-shaped hump. This work was motivated by the lack of DNS data of boundary-layer flows past roughness elements in a similar regime which is typical of civil aviation. The Mach and Reynolds numbers are chosen to be relevant for aeronautical applications when considering small imperfections at the leading edge of wings. We analyze different heights of the hump: The smaller heights result in a weakly nonlinear regime, while the larger result in a fully nonlinear regime with an increasing laminar separation bubble arising downstream of the roughness element and the formation of a pair of streamwise counterrotating vortices which appear to support themselves.}
}

A direct numerical simulation of a high-speed subsonic boundary layer meeting a small three-dimensional bump on a flat plate, in a regime typical of civil aviation. Taller bumps produce a separation bubble downstream and a pair of counter-rotating streamwise vortices.