Vailati Alberto, Cerbino Roberto, Mazzoni Stefano, Giglio Marzio, Nikolaenko Gennady, Takacs Christopher J, Cannell David S, Meyer William V, Smart Anthony E
CNR-Istituto Nationale per la Fisica della Materia and Dipartimento di Fisica, Università degli Studi di Milano, Italy.
Appl Opt. 2006 Apr 1;45(10):2155-65. doi: 10.1364/ao.45.002155.
We describe an experimental breadboard developed for the investigation of nonequilibrium fluctuations induced by macroscopic temperature and concentration gradients under microgravity conditions. Under these conditions the amplitude of the fluctuations diverges strongly for long wavelengths. The setup was developed at the University of Milan and at the University of California at Santa Barbara within the gradient-driven fluctuations experiment (GRADFLEX) project of the European Space Agency, in collaboration with the National Aeronautics and Space Administration. The apparatus uses a quantitative shadowgraph technique for characterization of the static power spectrum of the fluctuations S(q) and the measurement of their dynamics. We present preliminary experimental results for S(q) obtained in the presence of gravity for gradient-driven fluctuations for two cases, those induced in a liquid mixture with a concentration gradient produced by the Soret effect and those induced in a single-component fluid by a temperature gradient.
我们描述了一个用于研究微重力条件下由宏观温度和浓度梯度引起的非平衡涨落的实验模型。在这些条件下，涨落的幅度在长波长时会强烈发散。该装置是在米兰大学和加利福尼亚大学圣巴巴拉分校，与美国国家航空航天局合作，在欧洲航天局的梯度驱动涨落实验（GRADFLEX）项目中开发的。该仪器使用定量阴影图技术来表征涨落的静态功率谱S(q)并测量其动力学。我们展示了在重力存在的情况下，针对由索雷特效应产生浓度梯度的液体混合物中诱导的涨落以及由温度梯度在单组分流体中诱导的涨落这两种情况，所获得的S(q)的初步实验结果。
