Related papers: Boiling and cavitation caused by transient heat tr…
Superfluid helium-4 (He II) is a widely adopted coolant in scientific and engineering applications owing to its exceptional heat transfer capabilities. However, boiling can spontaneously occur on a heating surface in He II when the heat…
Transient heat transfer in superfluid $^4$He (He II) is a complex process that involves the interplay of the unique counterflow heat-transfer mode, the emission of second-sound waves, and the creation of quantized vortices. Many past…
I present here a microscopic theory for the superfluidity of $^4$He (He II) derived from experiments, and answer its essential questions. With a "momenton" model, the superfluid is shown to feature as a "harmonic superfluid". In which a new…
A sudden loss of vacuum can be catastrophic for particle accelerators. In such an event, air leaks into the liquid-helium-cooled accelerator beamline tube and condenses on its inner surface, causing rapid boiling of the helium and dangerous…
Miniature heaters are immersed in flows of quantum fluid and the efficiency of heat transfer is monitored versus velocity, superfluid fraction and time. The fluid is $^4$He helium with a superfluid fraction varied from 71% down to 0% and an…
Like many quantum fluids, superfluid helium-4 (He II) can be considered as a mixture of two miscible fluid components: an inviscid superfluid and a viscous normal fluid consisting of thermal quasiparticles [1]. A mutual friction between the…
This study experimentally investigated the influence of heat transfer from a heated hydrofoil on cavitating flow to understand the evaporation phenomenon under high-heat-flux and high-speed conditions. A temperature difference was generated…
Three dimensionality of 3D pulsed second sound wave in He II emitted from a finite size heater is experimentally investigated and theoretically studied based on two-fluid model in this study. The detailed propagation of 3D pulsed second…
Based on a first principles treatment of the excitation states we show that superfluidity of superfluid $^4$He (He II) results from a reduction in the number of phonon wavevector $K$ states $\N2(K)$ to a level that is negligibly low when…
Transition boiling is an intermediate regime occurring between nucleate boiling, where bubbles at the surface efficiently carry heat away, and film boiling, where a layer of vapor formed over the surface insulates the system reducing heat…
Liquid helium under negative pressures represents a unique possibility for studying nucleation and growth dynamics of cavities at low temperatures down to absolute zero. We analyze the growth dynamics of cavities and determine the…
Heat is carried in superfluid He-4 by the motion of the normal fluid$^{1}$, a counterflowing superfluid component serving to eliminate any net mass flow. It has been known for many years that above a critical heat current the superfluid…
We review a striking array of recent experiments, and their theoretical interpretations, on the superfluid transition in $^4$He in the presence of a heat flux, $Q$. We define and evaluate a new set of critical point exponents. The statics…
We explore transient heat transfer, on the millisecond time-scale, from a narrow, rectangular stainless steel heater cooled from one side by He II confined to a channel of 120 $\mu$m depth. The helium is isolated from the external bath with…
Spectral analysis of the translational superfluid flow of a Bose liquid is attempted. When cooling a dissipative flow of liquid helium 4 through a capillary at the lambda temperature,a superfluid flow abruptly appears at the lambda…
The macroscopic flow properties of pure He II are probed in the limit of zero temperature using an oscillating grid. With increasing oscillation amplitude the initially pure superflow changes abruptly: the resonant frequency decreases and…
Metal atoms and small clusters introduced into superfluid helium (He II) concentrate there in quantized vortices to form (by further coagulation) the thin nanowires. The nanowires' thickness and structure are well predicted by a…
We study heat transfer from a heated nanoparticle into surrounding fluid, using molecular dynamics simulations. We show that the fluid next to the nanoparticle can be heated well above its boiling point without a phase change. Under…
Using a functional-integral approach, we have determined the temperature below which cavitation in liquid helium is driven by thermally assisted quantum tunneling. For both helium isotopes, we have obtained the crossover temperature in the…
A theory of thermoelectric phenomena in superfluid $^4He$ is developed. It is found an estimation of the dipole moment of helium atom arising due to electron shell deformation caused by pushing forces from the side of its surrounding atoms.…