Numerical Analysis of Liquid Hydrogen Atomization in a Premixing Tube Using a Volume of Fluid-to-Discrete Particle Model Approach

Abstract

This paper examines the atomization characteristics of liquid hydrogen fuel in a premixing tube under different operating conditions. Hydrogen fuel’s unique injection morphology and atomization behavior were analyzed using the Volume of Fluid-to-Discrete Particle Model (VOF to DPM) approach, coupled with the SST k−ω turbulence model and adaptive mesh refinement. The study revealed that the breakup and transformation of liquid surfaces into particles are significantly impacted by varying air velocities and injection pressure. Specifically, higher air velocities caused the liquid sheet to lengthen and narrow due to intensified vortices. However, the breakup was delayed at higher velocities, occurring at distances of 0.037 m and 0.043 m for air velocities of 10 m/s and 20 m/s, respectively. The research also highlights the significant role that injection pressure plays in fluid sheet breakup. Higher pressures promote better atomization and fuel–lair mixing, resulting in more particles with increased diameters. Notably, the fluid sheet exhibited a small angle of about 43.79° when using the velocity component corresponding to p1 = 0.5 MPa. Similarly, for p2 = 1 MPa and p3 = 2 MPa, the angles were measured to be approximately 47.5° and 49.5°, respectively. Additionally, the study observed that the injection expands in length and diameter as time progresses, indicating fuel dispersion. These insights have significant implications for the design principles of injectors in power generation technologies that utilize liquid hydrogen fuel.

Keywords

• fluid sheet breakup
• particle diameter
• spray characteristics
• liquid hydrogen fuel
• premixing tube