Interaction of acoustic waves and micron-sized surface roughness elements in a swept-wing boundary layer
2016 (English)Report (Other academic)
E↵ect of acoustic waves on the control performance of distributed micron-sized roughness elements in a swept-wing boundary layer is investigated through direct numerical simulations. The flow configuration conforms to experiments by Kachanov et al. (2015) who observed either no significant influence of acoustic waves on the transition location or small stabilisation e↵ect. In this work, a base set up for natural transition scenario is first established by introducing unsteady background noise in the boundary layer. The natural transition is then delayed using control roughness elements. Introduction of acoustic waves to the controlled flow promotes the transition location. In all these flow cases, stationary primary crossflow vortices dominate the disturbance environment and unsteady disturbances experience an explosive growth prior to transition. The spatial distribution of the energy production associated with z-type modes shows an increase in the local transfer of energy from the modified mean flow to perturbations. Simulation of flow with control roughness elements and acoustic waves as the only source of unsteady disturbances shows no influence of acoustic wave in transition to turbulence.
Place, publisher, year, edition, pages
KTH Royal Institute of Technology, 2016.
Mechanical Engineering Fluid Mechanics and Acoustics
IdentifiersURN: urn:nbn:se:kth:diva-196875OAI: oai:DiVA.org:kth-196875DiVA: diva2:1049476
QC 201611252016-11-242016-11-242016-11-25Bibliographically approved