Continuous Mode Transition in High-speed Boundary-layers

Autor:	Paul A. Durbin, Jongwook Joo
Rok vydání:	2011
Předmět:	Physics General Chemical Engineering Direct numerical simulation General Physics and Astronomy Perturbation (astronomy) Inflow Mechanics Vorticity Physics::Fluid Dynamics symbols.namesake Boundary layer Classical mechanics Mach number Harmonics symbols Physical and Theoretical Chemistry Choked flow
Zdroj:	Flow, Turbulence and Combustion. 88:407-430
ISSN:	1573-1987 1386-6184
DOI:	10.1007/s10494-011-9372-x
Popis:	Mode interaction is studied via direct numerical simulations of a Mach 4.5 boundary layer with discrete and continuous modes imposed at the inflow. An approximate decoupling procedure is developed to create separate vortical, acoustic and entropic continuous mode components. Oblique horizontal vorticity modes induce boundary layer disturbances that grow with downstream distance, similarly to their incompressible counterpart. One salient difference is that a low frequency vorticity mode, alone, is found to induce transition by spawning two-dimensional, unstable discrete modes. The discrete modes are non-linearly excited at high harmonics of the inlet perturbation. Adding a Mack second mode, in addition to the vorticity mode, causes even earlier transition, suggesting that, in supersonic flow, unstable discrete modes play a crucial role in breakdown of boundary-layer streaks.
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_________::92233e105ec022f8ed6d3c13e09b3953 https://doi.org/10.1007/s10494-011-9372-x Zobrazit plný text záznamu Full text from SpringerLink