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Scaling evolution in shock-induced transition to turbulence
P Vorobieff1, N-G Mohamed, C Tomkins
1The University of New Mexico, Albuquerque, New Mexico 87131, USA.
Physical Review. E, Statistical, Nonlinear, and Soft Matter Physics
|February 3, 2004
Summary
This study examines shock-accelerated heavy gas (SF6) in air, revealing how Richtmyer-Meshkov instability drives vortex dynamics and turbulence. Findings show Kolmogorov scaling emerges in transitional flows, offering insights into turbulent mixing.
Area of Science:
- Fluid Dynamics
- Plasma Physics
- Turbulence Research
Background:
- Richtmyer-Meshkov instability is crucial in shock-accelerated interfaces.
- Understanding turbulent mixing in compressible flows is essential for various applications.
Purpose of the Study:
- To investigate the evolution of velocity statistics in a shock-accelerated gas column.
- To analyze the transition to turbulence and scaling laws in an anisotropic, inhomogeneous flow.
Main Methods:
- Experimental study using a planar Mach 1.2 shock wave.
- High-resolution measurements of two velocity components.
- Analysis of structure functions to examine velocity statistics and scaling.
Main Results:
- Repeatable large-scale vortex dynamics were observed post-shock passage.
- Secondary instabilities led to turbulence, exhibiting Kolmogorov scaling.
- Structure functions showed a trend towards Kolmogorov scaling, even in transitional, anisotropic, and inhomogeneous conditions.
Conclusions:
- The study demonstrates the emergence of Kolmogorov scaling in complex, transitional turbulent flows.
- Instantaneous and ensemble-averaged velocity statistics support early scaling trends.
- Findings contribute to the fundamental understanding of turbulent mixing and instability evolution.
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