Experiments on the Richtmyer-Meshkov instability of an air/SF6 interface

Abstract

Abstract.Results of flow visualization experiments of an impulsively accelerated plane interface between air and SF6 are reported. The shock tube used for the experiments has a larger test section than in previous experiments. The larger extent of uniform test flow relative to nonuniform boundary-layer flow permits unambiguous interpretation of flow-visualization photographs, and the influence of shockwave/boundary-layer interactions is no longer dominant. The strong wall vortex observed in previous studies is not observed in these experiments. It is found that the thin membrane, which forms the initially plane interface, has a significant influence on the initial growth rate of the interface thickness. However, the measured growth rates after the first reflected shock are independent of membrane configuration and are in good agreement with analytical predictions.

The late-time development of the Richtmyer–Meshkov instability

“…͑2͒. However, experiments in a larger shock tube 21 also yielded linear growth after reshock, with growth in better agreement with Eq. ͑2͒.…”

“…diam shock tube. 21,22 A square 267ϫ267 mm ͑10.5ϫ10.5 in.͒ test section 1.22 m long was adapted to the end of the shock tube by insertion of a ''cookie cutter'' into the circular cross section ͑Fig. 1͒.…”

“…However, near the center of the shock tube ͑on the vertical axis of symmetry of the wire mesh͒, the membrane was stretched against the upstream wires, as described by Vetter and Sturtevant. 21 This introduced higher harmonics into the nominally cosinusoidal shape. For example, the amplitude of the second harmonic, expressed as a percentage of the first harmonic, was 3.7% for Frames 1 and 2, 1.2% for Frame 3, and 0.9% for Frame 4.…”

“…The run procedure and instrumentation described by Vetter and Sturtevant 21 were used in these experiments. The initial test-section pressure was 23 kPa.…”

A study of planar Richtmyer-Meshkov instability in fluids with Mie-Grüneisen equations of state

“…A great deal of research has been performed on Richtmyer-Meshkov instability since its introduction. [9][10][11][12][13][14][15][16][17][18][19][20][21][22][23] A common component of most previously performed experimental and computational work has been the use of gases at conditions close to room temperature and pressure. In light of this, the current investigation is focused on exploring the role of the equation of state in RichtmyerMeshkov instability specifically in relation to commonly studied perfect gas cases.…”