A Lower Bound on Adiabatic Heating of Compressed Turbulence for Simulation and Model Validation

  title={A Lower Bound on Adiabatic Heating of Compressed Turbulence for Simulation and Model Validation},
  author={Seth Davidovits and Nathaniel J. Fisch},
  journal={The Astrophysical Journal},
The energy in turbulent flow can be amplified by compression, when the compression occurs on a timescale shorter than the turbulent dissipation time. This mechanism may play a part in sustaining turbulence in various astrophysical systems, including molecular clouds. The amount of turbulent amplification depends on the net effect of the compressive forcing and turbulent dissipation. By giving an argument for a bound on this dissipation, we give a lower bound for the scaling of the turbulent… 
Modeling turbulent energy behavior and sudden viscous dissipation in compressing plasma turbulence
We present a simple model for the turbulent kinetic energy behavior of subsonic plasma turbulence undergoing isotropic three-dimensional compression, which may exist in various inertial confinement
Understanding turbulence in compressing plasma as a quasi-EOS
Inspired by experimental Z-pinch results, we investigate plasma turbulence undergoing compression. In addition to Z-pinches, plasma turbulence can be compressed in a range of natural and laboratory
Understanding Turbulence in Compressing Plasmas and Its Exploitation or Prevention
Unprecedented densities and temperatures are now achieved in compressions of plasma, by lasers and by pulsed power, in major experimental facilities. These compressions, carried out at the largest
Preferential turbulence enhancement in two-dimensional compressions.
It is found that the nonlinearity can be insufficient to maintain isotropy in initially isotropic turbulence, with the energy components parallel to the compression coming to dominate the turbulent energy, with a number of consequences.
Turbulent stagnation in a Z-pinch plasma.
It is demonstrated how to reanalyze the spectroscopic data consistent with the turbulent picture and show that this leads to better concordance of the overconstrained spectroscopy measurements, while also substantially lowering the inferred mean density.
Recent progress in quantifying hydrodynamics instabilities and turbulence in inertial confinement fusion and high-energy-density experiments
  • A. Casner
  • Medicine, Physics
    Philosophical Transactions of the Royal Society A
  • 2020
The state of the art of nonlinear hydrodynamics and turbulent experiments, simulations and theory in ICF and high-energy-density plasmas are reviewed and perspectives towards in-depth understanding and control of these fascinating phenomena are drawn.
Bulk hydrodynamic stability and turbulent saturation in compressing hot spots
For hot spots compressed at constant velocity, we give a hydrodynamic stability criterion that describes the expected energy behavior of non-radial hydrodynamic motion for different classes of
Experimental determination of the thermal, turbulent, and rotational ion motion and magnetic field profiles in imploding plasmas
A tutorial is presented on advances in spectroscopic diagnostic methods developed for measuring key plasma properties in pulsed-power systems such as Z-pinches, magnetized-plasma compression devices,
Sub-structure formation in starless cores
Motivated by recent observational searches of sub-structure in starless molecular cloud cores, we investigate the evolution of density perturbations on scales smaller than the Jeans length embedded
Decay of Turbulence in Fluids with Polytropic Equations of State
We present numerical simulations of decaying hydrodynamic turbulence initially driven by solenoidal (divergence-free) and compressive (curl-free) driving. Most previous numerical studies for decaying


Adiabatic Heating of Contracting Turbulent Fluids
Turbulence influences the behavior of many astrophysical systems, frequently by providing non-thermal pressure support through random bulk motions. Although turbulence is commonly studied in systems
Hydrodynamical simulations of the decay of high-speed molecular turbulence – II. Divergence from isothermality
A roughly constant temperature over a wide range of densities is maintained in molecular clouds through radiative heating and cooling. An isothermal equation of state is therefore frequently employed
Compressing turbulence and sudden viscous dissipation with compression-dependent ionization state.
It is shown that, compared to cases with no ionization, ionization during compression is associated with larger increases in turbulent energy and can make the difference between growing and decreasing turbulent energy.
The Energy Dissipation Rate of Supersonic, Magnetohydrodynamic Turbulence in Molecular Clouds
Molecular clouds have broad line widths, which suggests turbulent supersonic motions in the clouds. These motions are usually invoked to explain why molecular clouds take much longer than a free-fall
Simulation and Modeling of Homogeneous Compressible Turbulence Under Isotropic Mean Compression
Compressible homogeneous turbulence subjected to isotropic mean compression is simulated numerically for high and low turbulent Mach numbers, at various compression rates. We find that at low Mach
Hydrodynamical simulations of the decay of high-speed molecular turbulence — I. Dense molecular regions
We present the results from three-dimensional hydrodynamical simulations of decaying high-speed turbulence in dense molecular clouds. We compare our results, which include a detailed cooling
Compressible turbulence: the cascade and its locality.
  • H. Aluie
  • Physics, Medicine
    Physical review letters
  • 2011
It is proved that interscale transfer of kinetic energy in compressible turbulence is dominated by local interactions, and establishes the existence of an ensuing inertial range over which mean subgrid scale kinetic energy flux becomes constant, independent of scale.
Direct numerical simulation of turbulence compressed in a cylinder
The behaviour of initially isotropic turbulence during compression in a cylinder is investigated by means of direct numerical simulation (DNS). The flow is governed by the 3D time-dependent
The conservative cascade of kinetic energy in compressible turbulence
The physical nature of compressible turbulence is of fundamental importance in a variety of astrophysical settings. We present the first direct evidence that mean kinetic energy cascades
Modeling of Non-Equilibrium Homogeneous Turbulence in Rapidly Compressed Flows
The response of homogeneous turbulence to rapid mean-flow compression in idealized internal combustion engines and rapid compression machines is examined using a hierarchy of closure models for the