Transition Delay in Hypervelocity Boundary Layers by Means of Vibrational Relaxation and Acoustic Instability Interactions
Abstract
A novel method to delay transition in hypervelocity flows by using non-equilibrium effects has been studied under Grant 13RQ14COR. The first molecule studied was carbon dioxide (CO2). The motivation arises from experimental and numerical data showing that when pure CO2 is in vibrational and chemical non-equilibrium, these relaxation processes absorb energy from acoustic disturbances whose growth in the boundary layer is responsible for transition through the 2nd or Mack mode in certain hypervelocity configurations. By absorbing energy at the same frequencies of the acoustic disturbances, nonequilibrium CO2 delays transition in hypervelocity flows. Before this program, no effort had been made to extend these results to CO2 injection into base air boundary layers.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jan 04, 2014
- Accession Number
- ADA598071
Entities
People
- Ivett Leyva
Organizations
- Air Force Research Laboratory