Large eddy simulation of unsteady flow in vortex diode

Vortex diode, as an important component in power fluidics, has been widely used in nuclear reprocessing engineering for about two decades. The fluidic system with vortex diodes is always working under a condition with a pulsant pneumatic power input. However, no detailed analysis of the unsteady flow inside the vortex diodes is available. Therefore, we carried out large eddy simulation (LES) to investigate the transient start-up process on the foundation of the experiment by Jacob et al. The numerical results were compared with the experimental data. It is shown that the special flow-time profiles in the start-up process are well predicted. From a further analysis on the internal flow, it is indicated that the change of flow rate with time is relevant to the varying of internal flow pattern and the swirling level. The above-mentioned methods and results of the vortex diode are of great guiding significance to predict the transient performance of the fluidic transfer system.