Modelling of a Liquid Metal Loop System : For X-ray Applications

Abstract: A closed system of a liquid metal jet loop operating in vacuum is modelled and investigated using a commercial 1D simulation tool. Possible methods to approximate a free-falling jet in vacuum to capture the behavior of the system in 1D is investigated. As the characteristics of the jet loop system is captured, the influence of different components on the system pressure and the jet nozzle flow rate is investigated further. The effects of the volume of the accumulator, the frictional forces within the check valves are inspected in isolation and the effect of an increased volume of alloy in the system is considered when system failure occurs due to check valve stiction. Several simulation tools are tested, and the simulations are ultimately performed using Simcenter AMESim 2019.2. The performance of the pump with respect to flow rate at different pressure levels are validated with measurement data acquired from the pump supplier as the Covid-19 virus limits the possibility to perform measurements in the lab. Ultimately, possible improvements of the system are suggested, and the conclusion is that a slightly larger accumulator volume would benefit the system, and that a larger volume of alloy would not prevent failure due to stiction forces in the inlet check valve. It is also confirmed that the check valves have major effects on the pressure and flow rate in the system.