Multi-Stream Near Wall-Turbulence Dynamics
Abstract
The experiments and Large Eddy Simulations described herein focus on a Multi-Aperture Rectangular Single Expansion Ramp Nozzle (MARS). The MARS flow field consists of two streams separated by a splitter plate; an (upper) supersonic core stream (Mach = 1.6) expanding through a single-sided expansion ramp and a (lower)bypass stream (Mach = 1) bounded by an aft deck at the bottom. Frequency dependent POD using experimentally validated LES data, indicates that the splitter plate is a highly sensitive region that remarkably alters the dynamics of the flow downstream of the trailing edge due to a two dimensional von Krmn-like shedding instability. This instability is shown to be potentially responsible for impairing the effectiveness of the bypass stream as a thermal and acoustic barrier between the core jet and the aft deck, and also to be exhibiting a global influence on the flow due to interaction with the shock train. To reduce these deleterious effects, the eigenspectrum obtained from linear stability is probed for unstable spanwise periodic disturbances and used to inspire surface modifications to the splitter plate trailing edge. The proposed chevron-like modifications have been employed both computationally and experimentally demonstrating their ability to excite three-dimensional instabilities in order to significantly reduce the growth of energy in the two-dimensional von Krmn shedding.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jun 21, 2023
- Accession Number
- AD1230453
Entities
People
- Mark Glauser
Organizations
- Syracuse University