Vorticity locking and pressure dynamics in finite-temperature superfluid turbulence

We present a numerical study of finite-temperature superfluid turbulence using the vor-tex filament model for superfluid helium. We examine the phenomenon of vorticity locking between the normal and superfluid components across a wide range of temperatures, using two different structures of external normal fluid drive. Our analysis is restricted to one-way coupling between the two components, and subject to this simplification, we show that vorticity locking increases with temperature leading to the superfluid flow being more influenced by the characteristics of the normal fluid. This results in stronger superfluid polarization and deviations from Gaussian statistics with a more probable occurrence of extreme fluctuations. We also examine how these properties influence the pressure field and attempt to verify a longstanding Pk proportional to k-7/3 theoretical quantum signature within the spatial pressure spectrum.

Automated summary

We conducted a numerical study on finite-temperature superfluid turbulence using the vortex filament model for superfluid helium. The phenomenon of vorticity locking between the normal and superfluid components was examined across a range of temperatures using two different structures of external normal fluid drive. Our analysis showed that vorticity locking increases with temperature, resulting in stronger superfluid polarization and deviations from Gaussian statistics with a higher likelihood of extreme fluctuations. We also investigated how these properties affect the pressure field and attempted to verify a theoretical quantum signature within the spatial pressure spectrum, specifically the Pk proportional to k-7/3 relationship.