Direct numerical simulations of a plane compressible wake: Stability, vorticity dynamics, and topology

Technical Report · Wed Nov 01 04:00:00 EST 1989

DOI:https://doi.org/10.2172/6912304· OSTI ID:6912304

Chen, J H; Cantwell, B J; Mansour, N N

Recent interest in supersonic combustion and problems of transatmospheric flight has prompted renewed research efforts in laminar-turbulent free shear flow transition. In the present work, linear stability theory and direct numerical simulations are used to study the effect of Mach number on the linear, nonlinear, and three-dimensional aspects of transition in a plane compressible wake. Direct numerical simulations are also used to study the sensitivity of a compressible wake to (1) phase effects and (2) two- and three-dimensional subharmonics. A linear stability analysis shows that the influence of increasing Mach number is stabilizing, resulting in reduced growth rates for both antisymmetric and symmetric modes of the wake. This reduction is due to baroclinic and dilatational effects as revealed from the linear eigenfunctions. For both low and high Mach numbers, the least stable wave is a two-dimensional antisymmetric mode aligned with the stream-wise direction. Three-dimensional simulations were performed to study the effect of phase angle between a fundamental and a pair of oblique waves on the development of the large-scale structures in a wake. Finally, the topology of the computed velocity, vorticity, and pressure gradient fields is determined using a generalized three-dimensional critical point theory. 78 refs., 83 figs.

• Research Organization: Stanford Univ., CA (USA). Thermosciences Div.
• Sponsoring Organization: DOE/DP
• DOE Contract Number: AC04-76DR00789
• OSTI ID: 6912304
• Report Number(s): SAND-90-8201; ON: DE90007934
• Country of Publication: United States
• Language: English

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CARTESIAN COORDINATES
CHEMICAL REACTION KINETICS
CHEMICAL REACTIONS
COMBUSTION
COMBUSTION KINETICS
COMPARATIVE EVALUATIONS
COMPRESSION
COMPUTER GRAPHICS
COORDINATES
DATA
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EARTH ATMOSPHERE
EXPERIMENTAL DATA
FLOW VISUALIZATION
FLUID FLOW
FREQUENCY ANALYSIS
HARMONICS
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INTERACTIONS
KINETICS
MATHEMATICAL MODELS
MEASURING METHODS
MECHANICS
NUMERICAL DATA
OSCILLATIONS
OXIDATION
PLUMES
PRESSURE GRADIENTS
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STABILITY
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THERMOCHEMICAL PROCESSES
THREE-DIMENSIONAL CALCULATIONS
TRANSITION FLOW
TURBULENT FLOW
TWO-DIMENSIONAL CALCULATIONS
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