[论文解读] Turbulent hydrogen premixed flames at high pressure and high temperature

Sofiane Al Kassar, Sara Cantagalli+3 more|arXiv (Cornell University)|Jan 22, 2026

Combustion and flame dynamics被引用 0

一句话总结

论文在1、5、20 atm下对湍流 lean premixed 氢燃烧的 DNS，比较同时在高压和高温下的湍流–火炬相互作用，揭示总体上适度变化但热扩散效应增强，切向应变普适性保持。

ABSTRACT

The combined influence of elevated pressure and temperature, representative of gas-turbine operating conditions, on lean premixed hydrogen flames is investigated using Direct Numerical Simulations (DNS) of a turbulent jet. Three cases are considered: 1 atm/298 K, 5 atm/472 K, and 20 atm/700 K, scaled to maintain the same jet Reynolds number and nominal Karlovitz number in the unburnt mixture, enabling a direct comparison of flame-turbulence interactions. Although the combined effects are moderate overall due to compensating influences, measurable differences arise in flame structure and turbulence-flame coupling. They are driven by reduced turbulence dissipation within the flame at high pressure and temperature, which enhances the interaction between turbulence and thermodiffusive effects. Finally, the tangential strain rate exhibits the same universal Kolmogorov scaling observed in homogeneous-isotropic turbulence and in methane flames, confirming its robustness for modelling turbulence

研究动机与目标

• Investigate how simultaneous increases in pressure and temperature affect lean premixed turbulent hydrogen flames.
• Enable direct comparison of turbulence–flame interactions across ambient and gas-turbine-like conditions by preserving key turbulence metrics.
• Assess thermodiffusive instability and its coupling with turbulence under elevated conditions.

提出的方法

• Direct Numerical Simulations of a turbulent hydrogen/air slot-jet flame at three conditions: 1 atm, 298 K; 5 atm, 472 K; 20 atm, 700 K.
• Inflow and grid setup scaled to keep jet Reynolds number and nominal Karlovitz number constant in the unburnt mixture.
• A nine-species chemical mechanism with transport via mixture-averaged properties is used, including a thermodiffusion (Soret) model.
• Low Mach number formulation with a semi-implicit finite-difference solver and Strang splitting for chemistry.
• Domain resolution ensures Δ/η ≤ 2 with Δ/δF ≈ 10 across a 1.4 billion grid-point simulation.
• Laminar references are used to interpret thermodiffusive behavior and flame-turbulence coupling.

实验结果

研究问题

• RQ1 How does simultaneous elevation of pressure and temperature influence turbulence–flame interactions in lean premixed hydrogen flames?
• RQ2 Do thermodiffusive effects strengthen or weaken with higher pressure and temperature in turbulent flames?
• RQ3 Is the universal Kolmogorov-based scaling of tangential strain preserved under gas-turbine-relevant conditions?
• RQ4 Can ambient-condition analyses extrapolate to high-pressure, high-temperature gas-turbine operation?

主要发现

• Simultaneous increases in pressure and temperature produce moderate but detectable changes in flame structure and turbulence–flame coupling.
• Higher pressure and temperature reduce turbulence dissipation inside the flame, sustaining stronger turbulence and enhancing thermodiffusive effects.
• Turbulent flame speed and reaction rate increase with elevated conditions, while flame surface area is less affected.
• The normalized tangential strain rate inside the flame follows a universal Kolmogorov scaling (~0.23 when normalised by the Kolmogorov time), invariant with pressure and temperature.
• The scaling approach enables higher in-flame turbulence levels without extra computational cost while maintaining similar thermodiffusive behavior in 2D.