Interactions between shocks and turbulence: Large eddy simulations

Conference · Sun Nov 01 04:00:00 EST 1992

OSTI ID:10158916

Buckingham, A C

When a shock moves into and interacts with an existing turbulent field, a substantial enhancement of the after-shock turbulent intensity and a simultaneous distortion and realignment of the tensor strain rate field and associated tensor stress field results. Component mixing, random advective transport, and diffusion and associated momentum and energy dissipation are often substantially intensified over their preshocked levels. A combination of low preshocked turbulent intensity and strong shocks evidently produces the most pronounced change in the level of turbulent intensity. Combinations of high preshocked turbulent intensity and weaker shocks result in more modest changes to the turbulent field but much more pronounced dynamical distortion and erratic motion of the shock front itself during the interaction. Recent experimental observations suggest that substantial turbulent intensification and pronounced shock front distortion persists even for shocks propagating at Mach numbers in excess of 100. This discussion investigates the physics of the interaction process using numerical simulations to supplement and analyze the existing experimental data base. Use has been made of direct two dimensional Monte Carlo simulations to examine the influence of upstream turbulence on shock structure and front topography. Linear viscoelastic turbulence response parameters were developed in modeling the interaction. Compressible, two-dimensional large eddy simulations (LES) have been applied. Predicted amplification levels, modal energy partition, shock translational to turbulence kinetic energy transfer, and viscoelastic response of turbulence to shock interaction are examined in comparison with available experimental evidence. Developments in two-band dynamic eddy viscosity modeling for the subgrid scales are being implemented to improve results of the LES in the near wall region, under the influence of stochastic subgrid scale backscatter, and near the shock.

• Research Organization: Lawrence Livermore National Lab., CA (United States)
• Sponsoring Organization: USDOE, Washington, DC (United States)
• DOE Contract Number: W-7405-ENG-48
• OSTI ID: 10158916
• Report Number(s): UCRL-JC--111562; CONF-9211128--9; ON: DE93013352
• Country of Publication: United States
• Language: English

Related Subjects

45 MILITARY TECHNOLOGY, WEAPONRY, AND NATIONAL DEFENSE
450200
ADVECTION
COMPRESSIBLE FLOW
DIFFUSION
ENERGY TRANSFER
KINETIC ENERGY
MACH NUMBER
MONTE CARLO METHOD
NUCLEAR EXPLOSIONS AND EXPLOSIVES
SHOCK WAVES
SIMULATION
STOCHASTIC PROCESSES
STRAIN RATE
TURBULENCE
TWO-DIMENSIONAL CALCULATIONS
VISCOSITY