Weakly nonlinear analysis of boundary layer receptivity to free-stream disturbances
2002 (English)In: Physics of fluids, ISSN 1070-6631, E-ISSN 1089-7666, Vol. 14, no 4, 1426-1441 p.Article in journal (Refereed) Published
The intent of the present paper is to study the receptivity of a zero pressure gradient boundary layer to free-stream disturbances with the aim to isolate the essential features involved in the generation of streamwise streaks. A weakly nonlinear formulation based on a perturbation expansion in the amplitude of the disturbance truncated at second order is used. It is shown that the perturbation model provide an efficient tool able to disentangle the sequence of events in the receptivity process. Two types of solutions are investigated: the first case amounts to the receptivity to oblique waves generated by a wave-like external forcing term oscillating in the free stream, the second the receptivity to free-stream turbulence-like disturbances, represented as a superposition of modes of the continuous spectrum of the Orr-Sommerfeld and Squire operators. A scaling property of the governing equations with the Reynolds number is also shown to be valid. The relation between this nonlinear receptivity process and previously investigated linear ones is also discussed.
Place, publisher, year, edition, pages
2002. Vol. 14, no 4, 1426-1441 p.
ORR-SOMMERFELD EQUATION, OPTIMAL PERTURBATIONS, CONTINUOUS-SPECTRUM, BYPASS TRANSITION, POISEUILLE FLOW, ENERGY GROWTH, SHEAR FLOWS, MECHANISM
IdentifiersURN: urn:nbn:se:kth:diva-12899DOI: 10.1063/1.1456062ISI: 000174319200016OAI: oai:DiVA.org:kth-12899DiVA: diva2:319561
QC 201005182010-05-182010-05-182010-05-18Bibliographically approved