Effects of Integral Scale on Darrieus–Landau Instability in Turbulent Premixed Flames (PDF)
发布时间：2025-04-30
点击次数：
- 发布时间：
- 2025-04-30
- 论文名称：
- Effects of Integral Scale on Darrieus–Landau Instability in Turbulent Premixed Flames (PDF)
- 发表刊物：
- Flow, Turbulence and Combustion
- 摘要：
- Previous studies have revealed the existence of distinct regimes of DL-stable and unstable turbulent flames, depending on whether the DL instability could be minimized or not. The mechanism of how mixture composition, flame macroscale and turbulence intensity, etc. act on DL instability has been extensively studied. Even though, the role played by turbulent length scale on DL instability is still unclear. The present study has been experimentally focused on the effect of turbulent integral scale on DL instability of premixed turbulent Bunsen flames. Flame fronts of C3H8/air mixture (ϕ = 0.8) under different turbulence conditions are captured by OH-PLIF technique. It is observed that the DL-unstable flames, obtained at relatively large integral scale and with cusps observed on the flame fronts, transform to be DL-stable flames with planar or disorderly wrinkled flame fronts as the integral scale decreases, indicating the indispensable role of integral scale on DL instability. These cusps on DL-unstable flame fronts decrease flame surface density while enlarge flame volume. Turbulent burning velocities of DL-unstable flames are augmented compared to DL-stable flames, leading to a similar dual-propagation model as observed in literatures. The threshold where turbulence shadows DL instability is analyzed by upgrading a previous model of [Phys. Rev. E 84 (2011) 026322]. The modified model is more reliable to demonstrate the DL-stable and unstable regimes in the Peters-Borghi’s diagram.
- 合写作者：
- Zhang WJ, Wang JH, Guo SL, Yu QQ, Jin W, Zhang M, Huang ZH
- 卷号：
- 2019, 103(1): 225-246
- 页面范围：
- 225-246
- 是否译文：
- 否
- 发表时间：
- 2019-06-10