Three-dimensional Numerical Simulation on Dispersion Process of Unsteady High Pressure Hydrogen Jet Flow

摘要

The numerical simulations on the high-pressure hydrogen jet are performed by using the unsteady three-dimensional compressible Navier-Stokes equations with multi-species conservation equations. The present numerical results show that the highly expanded hydrogen free jet observes and the distance between the Mach disc and the nozzle exit agrees well with the empirical equation. The time-averaged H_2 concentration of the numerical simulations agrees well with the experimental data and the empirical equation. The unsteady feature in the present numerical simulation shows that the PDF of the numerical simulations does not agree with the Gaussian PDF because the jet flow is "potential core" flow at x = 60 mm. Although higher hydrogen concentration is observed at x = 120 mm, the PDF in the numerical simulations agrees well with the Gaussian PDF at x = 180 mm. The numerical simulation of ignition in hydrogen jet is performed to show that the calculated OH distribution becomes isotropic expansion in the initial stage; however, OH flows along the leeward direction.