Investigation of the Richtmyer-Meshkov instability with double perturbation interface in nonuniform flows

A nonuniform ${\text{SF}}_6$ gas flow initial condition has been actualized in the context of shock tube experiment for the Richtmyer-Meshkov instability study. Two kinds of amplitude have been used to design the membrane supports which initially materialize the gaseous interface. The visualizations of $\text{air}/{\text{SF}}_6$ sinusoidal interfaces and shock wave propagations in the nonuniform field were obtained by Schlieren photography. Experiments are in very good agreement with simulations for the $\text{air}/{\text{SF}}_6$ case, but due to the initial nonuniform effects, Sadot model and Zhang-Sohn theory are far beyond the experimental and calculation results.

Figure 1

Initial structure diagram in the shock tube.

Figure 2

(Color online) Schlieren photography pictures and numerical simulation results by MVFT2D at a certain time (the sizes of the pictures are ones of the test window $\left[0.038\text{m},0.25\text{m}\right]\times \left[0.0\text{m},0.2\text{m}\right]$).

Figure 3

(Color online) Difference of interface shape, location, and shock front at $t=1.0\text{ms}$ between the initial uniform and nonuniform flows (the sizes of the pictures are the same as Fig. 2). (a) Initial uniform flow. (b) Initial nonuniform flow.

Figure 4

(Color online) Comparisons of the MVFT2D and MVFT3D results at two times (the sizes of the pictures are same as Fig. 2).

Figure 5

Bubble and spike locations in test window as well as three shock front line positions.

Figure 6

Shock front locations of the experiment and calculated results on the three test lines at different time.

Figure 7

Perturbation amplitudes history of the experiment, numerical computing, and comparison to the Sadot model and Zhang-Sohn theory, B1-S1 corresponds to the small perturbation amplitude, and B3-S3 corresponds to the large one (error bars of this visual measurement are equal to $\pm 10\mathrm{\%}$).

Figure 8

Perturbation amplitude history calculations of the initial uniform and nonuniform flows in RM instability.