Premium
Spreading of Linear Disturbances in Boundary Layers at Mach Number Five and the Effect of Wall Cooling
Author(s) -
Jocksch A.,
Kleiser L.
Publication year - 2015
Publication title -
pamm
Language(s) - English
Resource type - Journals
ISSN - 1617-7061
DOI - 10.1002/pamm.201510229
Subject(s) - mach number , inviscid flow , mechanics , boundary (topology) , instability , wave packet , physics , boundary layer , descent (aeronautics) , pressure gradient , turbulence , wavenumber , flow (mathematics) , mathematics , meteorology , mathematical analysis , optics , atomic physics
We determine inviscid eigensolutions in zero pressure gradient flat plate boundary layers at Mach number five and evaluate the eigensolutions with the method of steepest descent. The resulting wave packets show that with wall cooling the tail of the packets becomes slower. Although the boundary layers investigated are all convectively unstable we interpret the slow tail of the wave packets as a trend towards an absolute instability. From a comparison of the wave packets with turbulent spot transition, we conclude that for wall cooling the general transition properties are close to those of an absolutely unstable flow. (© 2015 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)