Abstract

This dissertation is investigating the turbulence behavior of highly under expanded hydrogen jet based on a 3D Navier-Stokes parallel solver and an extra transport equation for the hydrogen concentration. The solver uses an implicit conservative scheme on unstructured tetrahedral. The discretization exploits finite volumes and finite element with a second order of accurate flux calculation and time discretization. This work presents the extension of the code to simulate hydrogen jets based on Large Eddy Simulation (LES) model for turbulence while considering the real gas behavior. The developed code is equipped with a dynamic wiggle detector to reduce the contribution of the upwinding part in the flux calculation because upwind methodology adds undesired artificial viscosity to the solution.
For validation, the developed code is used to simulate a subsonic hydrogen jet. Considering similar studies among literature, good agreement is observed. Afterward, this tool is employed to numerically investigate a 70 MPa hydrogen jet release into ambient air. The turbulence effects in the principal and lateral jet direction are studied. During these simulations, the performance and stability of the developed numerical tool for high pressure ratio is reported.