Abstract:
The letter summarizes recent experiments on thermal counterflow turbulence in superfluid $^4$He, emphasizing the observation of turbulence in the normal fluid and its effect on the decay process when the heat flux is turned off. We argue that what is observed as turbulence in the normal fluid is a novel form of coupled turbulence in the superfluid and normal components, with injection of energy on the scales of both the (large) channel width and the (small) spacing between quantized vortices. Although an understanding of this coupled turbulence remains challenging, a theory of its decay is developed which accounts for the experimental observations.
European High-performance Infrastructures in Turbulence
312778
LS and EV acknowledge the support of the Czech Science Foundation under GACR 203/14/02005S. JG and WG acknowledge the support from the US Department of Energy under Grant DE-FG02 96ER40952 and the National Science Foundation under Grant # DMR-1507386. VL and AP acknowledge kind hospitality of Charles University in Prague that made
their contribution to this project possible. This work was partially supported by the European Community
Framework Programme 7, EuHIT – European High-performance Infrastructures in Turbulence, Grant Agreement # 312778.
Citation:
J. Gao, W. Guo, V. S. L'vov, A. Pomyalov, L. Skrbek, E. Varga, W. F. Vinen, “The decay of counterflow turbulence in superfluid $^4$He”, Pis'ma v Zh. Èksper. Teoret. Fiz., 103:10 (2016), 732–736; JETP Letters, 103:10 (2016), 648–652