Cryogenic helium is considered as a promising fluid for fundamental turbulence studies. Indeed, its properties at low temperature are such, that within a temperature range of 3 kelvins, it experiences:
(i) a phase transition (lambda point) between a superfluid (HeII) and a normal (HeI) phase;
(ii) the critical point occurs at 5.2 K, with a particular behaviour of some thermodynamic quantities, which can be exploited for advanced fundamental studies; (iii) moreover, the viscosity of helium at low temperature is so low, that huge Reynolds numbers can be generated easily, which makes this fluid ideally suited for laboratory experiments for developed turbulence.
Experiments at CEA Grenoble have been performed with both normal and superfluid helium in the TSF experiment (figure 2). The most salient results obtained at TSF are presented in Phys. Fluids 22, 125102 (2010).
Today, two facilities are proposed to external users: the large Von Karman Helium experiment (SHREK), and the superfluid helium jet experiment Hejet, described in Rev. Sci. Instrum. 82, 115109 (2011).
Maj : 11/07/2012 (772)