[논문 리뷰] Turbulent hydrogen premixed flames at high pressure and high temperature

Sofiane Al Kassar, Sara Cantagalli외 3명|arXiv (Cornell University)|2026. 01. 22.

Combustion and flame dynamics인용 수 0

한 줄 요약

이 논문은 난류 희점량 프렘믹스트 수소 화염의 DNS를 1, 5, 20 atm에서 수행하여 고압·고온이 동시에 미치는 영향 속에서 난류-플레임 상호작용을 비교하고, 전반적으로 보통의 변화는 있지만 열확산 효과가 강화되고 접선 응력의 보편성이 보존됨을 밝혀낸다.

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

연구 동기 및 목표

• Pressure와 Temperature의 동시 상승이 희점량 난류 수소 화염에 어떤 영향을 미치는지 조사한다.
• 주요 난류 지표를 보존하여 대기 조건과 가스터빈 유사 조건 간 난류-플레임 상호작용의 직접 비교를 가능하게 한다.
• elevated 조건에서 열확산 불안정성과 난류와의 결합을 평가한다.

제안 방법

• 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.

실험 결과

연구 질문

• 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?

주요 결과

• 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.