气液两相绕流钝体稳燃器的冷态数值研究

Numerical investigation of gas-liquid two-phase cold-flow around bluff-body stabilized burners

提出并建立了基于可变时间间隔平均方法的多尺度两相湍流模型,通过算例验证,证实了所推导的气液两相多尺度数学模型、所标定的模化参数及描述气液两相作用机理的合理性,及其计算的时间平均阻力系数、脉动升力系数误差、斯特劳哈尔数和回流区大小误差分别为1.45%,0.323%,2.17%,2.33%,计算结果明显优于标准k-ε和重整化群(RNG)k-ε模型.用多尺度湍流模型对气液两相绕流6个不同的钝体稳燃器进行数值计算表明:船形与锥形是综合性能较优的两个钝体稳燃器结构.其中,船形钝体比锥形钝体稳燃器回流区大10.53%,其时间平均阻力系数比锥形稳燃器大4.776%,方均根脉动升力系数比锥形稳燃器小44.73%,通过全方面综合比较,船形是综合性能最优的钝体稳燃器结构.

Based on the variable time interval average method, a multi-scale two-phase turbulent model was put forward and established. Compared with the experiment results, the rationality of the multi-scale gas-liquid two-phase mathematic model, the modeling pa- rameters and interactive mechanism of gas-liquid two-phase flows was proved. Its relative er- ror of drag coefficient was 1.45%, and the fluctuating lift coefficient was 0. 323%. This model could also accurately predict vortex shedding characteristics with its relative error of St was 2.17%. However, its relative error of size of the recirculation zone was 2.33%. And the computational results were better than those of the standard κ-ε and RNG （renormaliza- tion group） κ-ε models. Using the multi-scale two-phase turbulent model, the two-phase flow around six different bluff-body stabilized burners was predicted. The computational re- sults show that the ship-shaped and cone-shaped structures have good overall performance in these six different bluff-body stabilized burners. The reeireulation zone of ship-shaped struc- ture is larger than cone-shaped by 10. 53%. The time-averaged drag coefficient of ship- shaped structure is larger than cone-shaped by 4. 776%. The root-mean-square value of fluc- tuating lift coefficient of ship-shaped structure is smaller than cone-shaped by 44.73%. And by comprehensive comparison, the ship-shaped structure has the best performance.