A flow phase diagram for helium superfluids

The existence of the flow phase diagram predicted by Volovik [JETP Lett. 78, 553 (2003)] is discussed based on the available experimental data for He II and 3He-B. The effective temperature-dependent but scale-independent Reynolds number Reeff≡1/q≡(1−α′)/α, where α and α′ are the mutual friction parameters, and the superfluid Reynolds number characterizing the circulation of the superfluid component in units of the circulation quantum are used as the dynamic parameters. In particular, the flow diagram permits the identification of the experimentally observed turbulent states I and II in counterflowing He II with the classical and quantum turbulent regimes suggested by Volovik.