The first seminar “Modelling of materials – theory, model reduction and efficient numerical methods” will take place on Wednesday from 9:00 till 10:00 in the room K3. The talk will be given by Ondřej Kincl. Please see the details below.
Speaker: Ondřej Kincl
Title: Particle simulation of a superfluid fountain
Abstract: When helium-4 isotope is cooled below 2.17 K, it enters a state of matter called superfluid, whose unusual properties are large-scale manifestations of quantum physics. This fluid has zero viscosity, allowing it to creep frictionlessly through the pores of solid materials. When responding to a heat source, superfluid helium generates waves of temperature called second sound (in contrast to the diffusive evolution described by Fourier’s law). Moreover, superfluid converts heating power to mechanical motion with nearly perfect efficiency, as demonstrated by the fountain effect, where a laser or a small resistor drives superfluid against gravity.
In this talk, we will explain how superfluid helium-4 is described using the partial differential system of Landau and Tizsa. Then, we will present a novel numerical approximation based on Smoothed Particle Hydrodynamics, which allows us to make simulations of a superfluid fountain.