In this research, the nonlinear evolution of jet-like spikes in the single-mode ablative Rayleigh-Taylor instability （ARTI） in the presence of preheating, is studied numerically. It is demonstrated that the preheati...In this research, the nonlinear evolution of jet-like spikes in the single-mode ablative Rayleigh-Taylor instability （ARTI） in the presence of preheating, is studied numerically. It is demonstrated that the preheating plays an essential role in the formation of jet-like spikes in the nonlinear ARTI. The evolution of jet-like spikes in the ARTI with preheating consists of three stages with distinctly different distinguishing features. In the early stage, the preheating contributes to significantly increase the density-gradient scale length and broaden the velocity profile of the ablation surface, where the former can reduce the linear growth of the ARTI and mitigate the growth of its harmonics. In the middle stage, the ablative Kelvin-Helmholtz instability is dramatically suppressed due to the ablation effects. In the late stage, the jet＇s length （i.e. bubble-spike amplitude） is further increased by the bubble acceleration in the highly nonlinear ARTI, resulting eventually in the formation of jet-like spikes.展开更多
Ⅰ. INTRODUCTIONIt is very well known from the observations that some atmospheric motions are accompanied by jets in the boundary layer, for example, breezes and circulations in the mountain valleys (Gutman, 1969); no...Ⅰ. INTRODUCTIONIt is very well known from the observations that some atmospheric motions are accompanied by jets in the boundary layer, for example, breezes and circulations in the mountain valleys (Gutman, 1969); nocturnal increasing of wind (Byzova et al., 1989); cross-equatorial flow during the summer Indian monsoon (Das, 1986) and others. One of the important questions concerning a mathematical modelling of such motions is the problem of the turbulent closure of the equations set which describes the jet dynamics. It is still popular to use for the momentum turbulent flow (u＇w＇) a closure, based within the framework of K-theory on the Boussinesq hypothesis展开更多
The intermittent fluctuation of target evaporated particles is studied in both ring-like and jet-like events emitted in ^32 S-emulsion interactions at 200 A Ge V within the framework of multi-dimensional factorial mom...The intermittent fluctuation of target evaporated particles is studied in both ring-like and jet-like events emitted in ^32 S-emulsion interactions at 200 A Ge V within the framework of multi-dimensional factorial moment methodology using the concept of the Hurst exponent. It is observed that the intermittent fluctuation in the ring-like event is self-similar, whereas in the jet-like event fluctuation is self-affine. However, study indicates that the strength of fluctuation in the ring-like events is much stronger than that in the jet-like events.展开更多
基金supported by National Natural Science Foundation of China(Nos.10935003,11275031,11075024,11074300 and 11274026)National Basic Research Program of China(No.2013CB834100)China Postdoctoral Science Foundation(Nos.2011M500181,2012T50018)
文摘In this research, the nonlinear evolution of jet-like spikes in the single-mode ablative Rayleigh-Taylor instability （ARTI） in the presence of preheating, is studied numerically. It is demonstrated that the preheating plays an essential role in the formation of jet-like spikes in the nonlinear ARTI. The evolution of jet-like spikes in the ARTI with preheating consists of three stages with distinctly different distinguishing features. In the early stage, the preheating contributes to significantly increase the density-gradient scale length and broaden the velocity profile of the ablation surface, where the former can reduce the linear growth of the ARTI and mitigate the growth of its harmonics. In the middle stage, the ablative Kelvin-Helmholtz instability is dramatically suppressed due to the ablation effects. In the late stage, the jet＇s length （i.e. bubble-spike amplitude） is further increased by the bubble acceleration in the highly nonlinear ARTI, resulting eventually in the formation of jet-like spikes.
文摘Ⅰ. INTRODUCTIONIt is very well known from the observations that some atmospheric motions are accompanied by jets in the boundary layer, for example, breezes and circulations in the mountain valleys (Gutman, 1969); nocturnal increasing of wind (Byzova et al., 1989); cross-equatorial flow during the summer Indian monsoon (Das, 1986) and others. One of the important questions concerning a mathematical modelling of such motions is the problem of the turbulent closure of the equations set which describes the jet dynamics. It is still popular to use for the momentum turbulent flow (u＇w＇) a closure, based within the framework of K-theory on the Boussinesq hypothesis
文摘The intermittent fluctuation of target evaporated particles is studied in both ring-like and jet-like events emitted in ^32 S-emulsion interactions at 200 A Ge V within the framework of multi-dimensional factorial moment methodology using the concept of the Hurst exponent. It is observed that the intermittent fluctuation in the ring-like event is self-similar, whereas in the jet-like event fluctuation is self-affine. However, study indicates that the strength of fluctuation in the ring-like events is much stronger than that in the jet-like events.
