Spreading of Linear Disturbances in Boundary Layers at Mach Number Five and the Effect of Wall Cooling |
| |
| Authors: | A Jocksch L Kleiser |
| |
| Institution: | 1. CSCS – Swiss National Supercomputing Centre, Via Trevano 131, 6900 Lugano, Switzerland;2. Institute of Fluid Dynamics, ETH Zurich, 8092 Zurich, Switzerland |
| |
| Abstract: | 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) |
| |
| Keywords: | |
|
|
