Direct Numerical Simulations of Non-reacting and Reacting Sonic Hydrogen Jets Injected into Supersonic Crossflows

Strategic Insights -

Researchers at Zhejiang University have conducted a comprehensive study on the behavior of sonic hydrogen jets injected into supersonic crossflows, with and without chemical reactions. The investigation aims to understand the interaction between shock waves and turbulence in the windward shear layer. The study reveals that combustion mainly occurs in the fuel-rich region, with a higher reaction intensity on the windward side, which decays as the jet develops. Quantitative analysis shows that combustion slightly reduces the streamwise velocity near the wall, increases the normal velocity, and influences both turbulent kinetic energy and Reynolds stresses.

Key Takeaways:

  • The researchers performed direct numerical simulation to investigate the shock and flow characteristics of a sonic hydrogen jet injected into a Mach 3.38 turbulent boundary layer without and with chemical reactions.
  • The interaction between shock waves and turbulence in the windward shear layer is intensive, with sharp compression leading to a temperature increase, resulting in a minimal difference of thermal and flow structures between the two cases.
  • In the reacting case, combustion mainly occurs in the fuel-rich region, with a higher reaction intensity on the windward side that decays as the jet develops.
  • Combustion affects the vorticity dynamics, with vortex stretching and volume expansion being the main contributors of vorticity generation in the windward side.
  • Combustion slightly increases the volume expansion term in the upstream recirculation and shear layers, and significantly enhances the baroclinic term in the windward shear layer.
  • The study concluded that combustion impacts the flow structures, including the streamwise velocity, normal velocity, and turbulent kinetic energy.
  • The research was funded by the National Natural Science Foundation of China (NSFC) and has been peer-reviewed.

Statistics:

  • Mach number of the turbulent boundary layer: 3.38
  • Temperature difference between the two cases: 5%
  • Compressive ratio in the windward shear layer: not specified
  • Reynolds stresses influenced by combustion: not specified
  • Volume expansion term in the upstream recirculation and shear layers: not specified
  • Baroclinic term in the windward shear layer: not specified

Sources:

  • Direct Numerical Simulations of Non-reacting and Reacting Sonic Hydrogen Jets Injected Into Supersonic Crossflows. Physics of Fluids, 2025; 37(8).
  • National Natural Science Foundation of China (NSFC).
  • Aip Publishing, 1305 Walt Whitman Rd, Ste 300, Melville, NY 11747-4501, USA (www.aip.org/; Physics of Fluids - pof.aip.org/)
  • Zhejiang University, State Key Laboratory of Clean Energy Utilization, Hangzhou 310027, People's Republic of China.