Amplification of turbulence through multiple planar shocks.

Area of Science:

• Plasma Physics
• Astrophysical Fluid Dynamics
• Computational Physics

Background:

• Turbulence amplification is crucial for understanding energy dissipation in astrophysical and laboratory plasmas.
• Collisional shocks are common phenomena that can significantly alter turbulent properties.

Purpose of the Study:

• To investigate the amplification of isotropic, incompressible turbulence through multiple planar, collisional shocks.
• To analyze the impact of shock timing and ordering on turbulence amplification.

Main Methods:

• Analytical linear theory was employed to study turbulence amplification.
• Two limiting cases were explored: rapid shocks and shocks with intervening isotropization time.

Main Results:

• In the case of sufficient time for isotropization, weak multishock amplification is insensitive to thermal vs. vortical pressure distinctions.
• When turbulence does not re-isotropize, anisotropy generated by shocks feeds back, altering amplification.
• Amplification is sensitive to shock ordering, with identical mean postshock fields yielding distinct turbulent amplification.

Conclusions:

• The timing and ordering of collisional shocks critically influence turbulence amplification.
• Anisotropic turbulence generated between shocks can modify subsequent amplification.
• Understanding these effects is key for accurate modeling of turbulent phenomena in various physical systems.