Gandikota G, Chatain D, Amiroudine S, Lyubimova T, Beysens D
SBT, UMR-E CEA/UJF-Grenoble 1, INAC, Grenoble F-38054, France.
Université Bordeaux 1, Institut de Mécanique et d'Ingénierie, UMR CNRS 5295, 16 Av. Pey-Berland, 33607 Pessac Cedex, France.
Phys Rev E Stat Nonlin Soft Matter Phys. 2014 Jan;89(1):013022. doi: 10.1103/PhysRevE.89.013022. Epub 2014 Jan 28.
Experiments on near-critical hydrogen have been conducted under magnetic compensation of gravity to investigate the Faraday instability that arises at the liquid-vapor interface under zero-gravity conditions. We investigated such instability in the absence of stabilizing gravity. Under such conditions, vibration orients the interface and can destabilize it. The experiments confirm the existence of Faraday waves and demonstrate a transition from a square to a line pattern close to the critical point. They also show a transition very close to the critical point from Faraday to periodic layering of the vapor-liquid interface perpendicular to vibration. It was seen that the Faraday wave instability is favored when the liquid-vapor density difference is large enough (fluid far from the critical point), whereas periodic layering predominates for small difference in the liquid and vapor densities (close to the critical point). It was observed for the Faraday wave instability that the wavelength of the instability decreases as one approaches the critical point. The experimental results demonstrate good agreement to the dispersion relation for zero gravity except for temperatures very close to the critical point where a transition from a square pattern to a line pattern is detected, similarly to what is observed under 1g conditions.
在重力磁补偿条件下对近临界氢进行了实验，以研究在零重力条件下液-气界面出现的法拉第不稳定性。我们在没有稳定重力的情况下研究了这种不稳定性。在这种条件下，振动会使界面定向并使其失稳。实验证实了法拉第波的存在，并展示了在接近临界点时从方形图案到线形图案的转变。它们还显示了在非常接近临界点时从法拉第状态到垂直于振动的气液界面周期性分层的转变。可以看出，当液-气密度差足够大时（流体远离临界点），法拉第波不稳定性更有利，而当液体和蒸汽密度差异较小时（接近临界点），周期性分层占主导。对于法拉第波不稳定性，观察到随着接近临界点，不稳定性的波长会减小。实验结果表明，除了非常接近临界点的温度外，与零重力下的色散关系具有良好的一致性，在该温度下检测到从方形图案到线形图案的转变，这与在1g条件下观察到的情况类似。
