Effect of Atwood number on convergent Richtmyer–Meshkov instability

Tang, Jinggang; Zhang, Fu; Luo, Xisheng; Zhai, Zhigang

doi:10.1007/s10409-020-01015-5

Cited by 10 publications

(7 citation statements)

References 36 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The initially incident shock wave is set to travel inward with a Mach number of 1.29 and a radius of 34.0 mm, as sketched in figure 2(a). The initial postshock flow is supposed to be uniform and calculated according to the Rankine-Hugoniot relation, which coincides with the recent numerical studies on the convergent RM instability (Zhai et al 2019b;Zhou et al 2020b;Li et al 2021;Tang et al 2021;Wu et al 2021;Yan et al 2022).…”

Section: Numerical Schemesupporting

confidence: 65%

“…Numerical simulations are performed to obtain the detailed flow field required for an in-depth analysis of flow regimes. The process of a cylindrically convergent shock interacting with a gaseous interface examined in this study is described by compressible Euler equations, which coincide with the numerical studies focusing on the early-to-intermediate regimes of RM instability with or without the reshock (Grove et al 1993;Holmes & Grove 1995;Holmes et al 1999;Herrmann, Moin & Abarzhi 2008;Niederhaus et al 2008;Leinov et al 2009;Ding et al 2017bDing et al , 2018Zhai et al 2017Zhai et al , 2018aZhai, Ou & Ding 2019a;Zhai et al 2019b;Zou et al 2019;Igra & Igra 2020;Zhou et al 2020b;Tang et al 2021). An upwind space-time conservation elements/solution elements scheme is utilized with second-order accuracy in both space and time (Shen et al 2015a;Shen, Wen & Zhang 2015b;Shen & Wen 2016).…”

Section: Numerical Schemesupporting

confidence: 63%

“…2020 b ; Tang et al. 2021). An upwind space–time conservation elements/solution elements scheme is utilized with second-order accuracy in both space and time (Shen et al.…”

Section: Experimental and Numerical Methodsmentioning

confidence: 99%

See 2 more Smart Citations

Hydrodynamic instabilities of a dual-mode air–SF₆ interface induced by a cylindrically convergent shock

Liu

Luo

et al. 2023

J. Fluid Mech.

Self Cite

View full text Add to dashboard Cite

Shock-tube experiments are performed on the convergent Richtmyer–Meshkov (RM) instability of a multimode interface. The temporal growth of each Fourier mode perturbation is measured. The hydrodynamic instabilities, including the RM instability and the additional Rayleigh–Taylor (RT) effect, imposed by the convergent shock wave on the dual-mode interface, are investigated. The mode-coupling effect on the convergent RM instability coupled with the RT effect is quantified. It is evident that the amplitude growths of all first-order modes and second-order harmonics and their couplings depend on the variance of the interface radius, and are influenced by the mode-coupling from the very beginning. It is confirmed that the mode-coupling mechanism is closely related to the initial spectrum, including azimuthal wavenumbers, relative phases and initial amplitudes of the constituent modes. Different from the conclusion in previous studies on the convergent single-mode RM instability that the additional RT effect always suppresses the perturbation growth, the mode-coupling might result in the additional RT effect promoting the instability of the constituent Fourier mode. By considering the geometry convergence, the mode-coupling effect and other physical mechanisms, second-order nonlinear solutions are established to predict the RM instability and the additional RT effect in the cylindrical geometry, reasonably quantifying the amplitude growths of each mode, harmonic and coupling. The nonlinear solutions are further validated by simulations considering various initial spectra. Last, the temporal evolutions of the mixed mass and normalized mixed mass of a shocked multimode interface are calculated numerically to quantify the mixing of two fluids in the cylindrical geometry.

show abstract

Section: Numerical Schemesupporting

confidence: 65%

Section: Numerical Schemesupporting

confidence: 63%

See 1 more Smart Citation

Hydrodynamic instabilities of a dual-mode air–SF₆ interface induced by a cylindrically convergent shock

Liu

Luo

et al. 2023

J. Fluid Mech.

Self Cite

View full text Add to dashboard Cite

show abstract

“… 55 A study in China has shown that 16.53% of oral GCs were used for inappropriate indications. 56 After the implementation of the Guidelines for Clinical Application of GCs, the clinical utilization of GCs in economically developed cities in China has become more rationalized. However, inadequate implementation of relevant management measures in less developed areas of southwest China still leads to prominent inappropriate use of GCs.…”

Section: Discussionmentioning

confidence: 99%

Trends and Patterns of Systemic Glucocorticoid Prescription in Primary Care Institutions in Southwest China, from 2018 to 2021

Li,

Zeng,

Fan

et al. 2023

RMHP

View full text Add to dashboard Cite

Purpose The purpose of this study was to investigate the prescribing patterns and usage trends of systemic glucocorticoids in primary care institutions located in Southwest China from 2018 to 2021. Materials and Methods A retrospective cross-sectional analysis of systemic glucocorticoids prescriptions was conducted in 32 primary care institutions located in Southwest China between 2018 and 2021. Prescriptions of systemic glucocorticoids were classified as appropriate or inappropriate use. Inappropriate use was further classified into (1) inappropriate indications and (2) inappropriate selection of glucocorticoids. Generalized estimation equations were employed to investigate the factors associated with inappropriate utilization of systemic glucocorticoids. The seasonal autoregressive integrated moving average (SARIMA) model was employed to predict the rate of inappropriate glucocorticoids prescriptions. Results A total of 203,846 (92.89%) prescriptions were included, both the number of systemic glucocorticoids prescriptions and inappropriate prescriptions increased in winter. Diseases of the respiratory system (68.90%) were the most frequent targets of systemic glucocorticoids use. Of all prescriptions, 73.18% exhibited inappropriate indications, while 0.05% demonstrated inappropriate selection. The utilization of systemic glucocorticoids was deemed inappropriate for diseases of the respiratory system (94.19%), followed by diseases of the digestive system (87.75%). Physicians, who were female or younger than 33 years old, possess lower levels of education and professional titles and exhibit a higher likelihood of inappropriately prescribing systemic glucocorticoids. The phenomenon of inappropriate glucocorticoids use was commoner among male patients aged 65 years and older. After conducting model verification, it was determined that the SARIMA model could be used to predict the monthly rate of inappropriate systemic glucocorticoids prescriptions in primary care institutions in southwest China. Conclusion The inappropriate use of systemic glucocorticoids remains a significant concern in primary care institutions. In this regard, continuing education and professional knowledge training of physicians should be strengthened in the future.

show abstract

“…Hydrodynamic instability-driven mixing processes are ubiquitous in nature, and of great significance both for fundamental research and for engineering application in a number of research fields, including Inertial Confinement Fusion (ICF), astrophysical phenomena, and supersonic combustion. In the last several decades, much attention has been paid to the challenging problem [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20] .…”

Section: Introductionmentioning

confidence: 99%

Effects of the initial perturbations on the Rayleigh-Taylor-Kelvin-Helmholtz instability system

Chen,

Xu,

Zhang

et al. 2021

Preprint

View full text Add to dashboard Cite

In the paper, the effects of initial perturbations on the Rayleigh-Taylor instability (RTI), Kelvin-Helmholtz instability (KHI), and the coupled Rayleigh-Taylor-Kelvin-Helmholtz instability (RTKHI) systems are investigated using a multiple-relaxation-time discrete Boltzmann model. Six different perturbation interfaces are designed to study the effects of the initial perturbations on the instability systems. It is found that the initial perturbation has a significant influence on the evolution of RTI. The sharper the interface, the faster the growth of bubble or spike. While the influence of initial interface shape on KHI evolution can be ignored. Based on the mean heat flux strength D 3,1 , the effects of initial interfaces on the coupled RTKHI are examined in detail. The research is focused on two aspects: (i) the main mechanism in the early stage of the RTKHI, (ii) the transition point from KHI-like to RTI-like for the case where the KHI dominates at earlier time and the RTI dominates at later time. It is found that the early main mechanism is related to the shape of the initial interface, which is represented by both the bilateral contact angle θ 1 and the middle contact angle θ 2 . The increase of θ 1 and the decrease of θ 2 have opposite effects on the critical velocity. When θ 2 remains roughly unchanged at 90 degrees, if θ 1 is greater than 90 degrees (such as the parabolic interface), the critical shear velocity increases with the increase of θ 1 , and the ellipse perturbation is its limiting case; If θ 1 is less than 90 degrees (such as the inverted parabolic and the inverted ellipse disturbances), the critical shear velocities are basically the same, which is less than that of the sinusoidal and sawtooth disturbances. The influence of inverted parabolic and inverted ellipse perturbations on the transition point of the RTKHI system is greater than that of other interfaces: (i) For the same amplitude, the smaller the contact angle θ 1 , the later the transition point appears; (ii) For the same interface morphology, the disturbance amplitude increases, resulting in a shorter duration of the linear growth stage, so the transition point is greatly advanced.

show abstract

Effect of Atwood number on convergent Richtmyer–Meshkov instability

Cited by 10 publications

References 36 publications

Hydrodynamic instabilities of a dual-mode air–SF₆ interface induced by a cylindrically convergent shock

Hydrodynamic instabilities of a dual-mode air–SF₆ interface induced by a cylindrically convergent shock

Trends and Patterns of Systemic Glucocorticoid Prescription in Primary Care Institutions in Southwest China, from 2018 to 2021

Effects of the initial perturbations on the Rayleigh-Taylor-Kelvin-Helmholtz instability system

Contact Info

Product

Resources

About

Effect of Atwood number on convergent Richtmyer–Meshkov instability

Cited by 10 publications

References 36 publications

Hydrodynamic instabilities of a dual-mode air–SF6 interface induced by a cylindrically convergent shock

Hydrodynamic instabilities of a dual-mode air–SF6 interface induced by a cylindrically convergent shock

Trends and Patterns of Systemic Glucocorticoid Prescription in Primary Care Institutions in Southwest China, from 2018 to 2021

Effects of the initial perturbations on the Rayleigh-Taylor-Kelvin-Helmholtz instability system

Contact Info

Product

Resources

About

Hydrodynamic instabilities of a dual-mode air–SF₆ interface induced by a cylindrically convergent shock

Hydrodynamic instabilities of a dual-mode air–SF₆ interface induced by a cylindrically convergent shock