The effect of compressibility on the primary global instability of unforced laminar separation bubbles

Autor(es)

Gennaro, E. M. ^[1] ; Souza, B. D. P. ^[1] ; Rodriguez, D. ^[2]

Afiliação do(s) autor(es)

^[1] Sao Paulo State Univ UNESP, Campus Sao Joao da Boa Vista, BR-13876750 Sao Joao Da Boa Vista, SP - Brazil

^[2] Univ Politecn Madrid, ETSIAE UPM Sch Aeronaut, Plaza Cardenal Cisneros 3, E-28040 Madrid - Spain

• Tipo de documento: Artigo de Revisão
• Fonte: Journal of the Brazilian Society of Mechanical Sciences and Engineering; v. 41, n. 12 DEC 2019.
• Citações Web of Science: 0

Resumo

Laminar separation bubbles present a three-dimensional self-excited instability mechanism which leads to the appearance of spanwise-periodic structures. In incompressible flow, this mechanism was found to become active at conditions in which wave-like, two-dimensional perturbations are only convectively unstable. In the absence of continuous external excitation, the three-dimensional instability is expected to dominate the flow dynamics and initiate the laminar-turbulent transition. This work extends previous analyses by incorporating the effect of compressibility at subsonic conditions. Two-dimensional numerical simulations of a flat-plate boundary layer with a prescribed free-stream deceleration and acceleration are carried out to obtain a set of model laminar separation bubbles. A linear stability analysis is applied then, to study the influence of Reynolds and Mach numbers on the three-dimensional instability. (AU)

• Processo FAPESP: 15/26759-9 - Análise da instabilidade global de uma bolha de separação laminar compressível
• Beneficiário: Bruna Dias Pires de Souza
• Modalidade de apoio: Bolsas no Brasil - Iniciação Científica
• Processo FAPESP: 17/01586-0 - Instabilidade de escoamentos separados em aplicações aeronáuticas
• Beneficiário: Elmer Mateus Gennaro
• Modalidade de apoio: Auxílio à Pesquisa - Regular