# Numerical Simulation

A numerical model was developed to simulate the oscillation of a pure Zr droplet using the ANSYS Fluent CFD package. For the numerical modeling, one arbitrary oscillation at 1974 °C was used. For this case, the measured oscillation frequency and the corresponding surface tension are 168.88 Hz and 1.452 N-m^{-1} respectively. The simulations had two phases, zirconium and helium, with zirconium forming the inner phase and helium forming the surrounding atmosphere. Densities of zirconium and helium used in the numerical model were 5891.74 and 0.1625 kg-m ^{3 }respectively [4]. The mass loss in sample before and after the experiment is as 0.043% and hence neglected in simulation. Since the experiment is conducted in vacuum, oxidation was neglected in the numerical model. Diameter of the zirconium phase was calculated using density and mass of the sample from the experiments. The viscosity of Zr was set as 4.194 mPa-s [5].

**Fig. 2 **Geometry of the problem. *Black portion *represents the helium phase and *white portion* is the Zirconium phase

The geometry, mesh and solution parameters are discussed below. A video was generated using images at each timeframe to observe the oscillations. A code was developed using Matlab to analyze the video and was discussed further in this paper. The parameters for the numerical model are discussed below.