TY - JOUR
T1 - Numerical study on Rayleigh-Taylor effect on cylindrically converging Richtmyer-Meshkov instability
AU - Zhai, Zhi Gang
AU - Zhang, Fu
AU - Zhou, Zhang Bo
AU - Ding, Ju Chun
AU - Wen, Chih Yung
PY - 2019/12/1
Y1 - 2019/12/1
N2 - Evolution of a two-dimensional air/SF6 single-mode interface is numerically investigated by an upwind CE/SE method under a cylindrically converging circumstance. The Rayleigh-Taylor effect caused by the flow deceleration on the phase inversion (RTPI) is highlighted. The RTPI was firstly observed in our previous experiment, but the related mechanism remains unclear. By isolating the three-dimensional effect, it is found here that the initial amplitude (a0), the azimuthal mode number (k0) and the re-shocking moment are the three major parameters which determine the RTPI occurrence. In the variable space of (k0, a0), a critical a0 for the RTPI occurrence is solved for each k0, and there exists a threshold value of k0 below which the RTPI will not occur no matter what a0 is. There exists a special k0 corresponding to the largest critical a0, and the reduction rule of critical a0 with k0 can be well described by an exponential decay function. The results show that the occurrence of the RTPI requires a small a0 which should be less than a critical value, a large k0 which should exceed a threshold, and a right impinging moment of the re-shock which should be later than the RTPI occurrence. Finally, the effects of the incident shock strength, the density ratio and the initial position of the interface on the threshold value of k0 and on the maximum critical a0 are examined. These new findings would facilitate the understanding of the converging Richtmyer-Meshkov instability and would be helpful for designing an optimal structure of the inertia confinement fusion capsule.
AB - Evolution of a two-dimensional air/SF6 single-mode interface is numerically investigated by an upwind CE/SE method under a cylindrically converging circumstance. The Rayleigh-Taylor effect caused by the flow deceleration on the phase inversion (RTPI) is highlighted. The RTPI was firstly observed in our previous experiment, but the related mechanism remains unclear. By isolating the three-dimensional effect, it is found here that the initial amplitude (a0), the azimuthal mode number (k0) and the re-shocking moment are the three major parameters which determine the RTPI occurrence. In the variable space of (k0, a0), a critical a0 for the RTPI occurrence is solved for each k0, and there exists a threshold value of k0 below which the RTPI will not occur no matter what a0 is. There exists a special k0 corresponding to the largest critical a0, and the reduction rule of critical a0 with k0 can be well described by an exponential decay function. The results show that the occurrence of the RTPI requires a small a0 which should be less than a critical value, a large k0 which should exceed a threshold, and a right impinging moment of the re-shock which should be later than the RTPI occurrence. Finally, the effects of the incident shock strength, the density ratio and the initial position of the interface on the threshold value of k0 and on the maximum critical a0 are examined. These new findings would facilitate the understanding of the converging Richtmyer-Meshkov instability and would be helpful for designing an optimal structure of the inertia confinement fusion capsule.
KW - converging shock wave
KW - Rayleigh-Taylor effect
KW - Richtmyer-Meshkov instability
UR - http://www.scopus.com/inward/record.url?scp=85071618427&partnerID=8YFLogxK
U2 - 10.1007/s11433-019-9441-4
DO - 10.1007/s11433-019-9441-4
M3 - Journal article
AN - SCOPUS:85071618427
SN - 1674-7348
VL - 62
JO - Science China: Physics, Mechanics and Astronomy
JF - Science China: Physics, Mechanics and Astronomy
IS - 12
M1 - 124712
ER -