Localised optimal initial perturbations are studied to gain an understanding of the global stability properties of streamwise corner-flow. A self-similar and a modified base-flow are considered. The latter mimics a characteristic deviation from the self-similar solution, commonly observed in experiment. Poweriterations in terms of subsequent direct and adjoint linearised Navier-Stokes solution sweeps are employed to converge optimal solutions for two optimisation times. The optimal response manifests as a wave packet that initially gains energy through the Orr mechanism and continues growing exponentially thereafter. The study at hand represents the first global stability analysis of streamwise corner-flow and confirms key observations made in theoretical and/or experimental work on the subject. Namely, the presence of an inviscid instability mechanism in the near-corner region and a destabilising effect of the characteristic mean-flow deformation found in experiment. / <p>QC 20130604</p>
| Identifer | oai:union.ndltd.org:UPSALLA1/oai:DiVA.org:kth-123194 |
| Date | January 2013 |
| Creators | Schmidt, Oliver T., Hosseini, Seyed M., Rist, Ulrich, Hanifi, Ardeshir, Henningson, Dan |
| Publisher | KTH, Stabilitet, Transition, Kontroll, KTH, Linné Flow Center, FLOW, KTH, Stabilitet, Transition, Kontroll, KTH, Linné Flow Center, FLOW, KTH, Stabilitet, Transition, Kontroll, KTH, Linné Flow Center, FLOW, KTH, Stabilitet, Transition, Kontroll, KTH, Linné Flow Center, FLOW, KTH, Stabilitet, Transition, Kontroll, KTH, Linné Flow Center, FLOW, Stockholm |
| Source Sets | DiVA Archive at Upsalla University |
| Language | English |
| Detected Language | English |
| Type | Report, info:eu-repo/semantics/report, text |
| Format | application/pdf |
| Rights | info:eu-repo/semantics/openAccess |
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