应用修正的k-ε模型研究超声速H2／Air燃烧

Numerical simulation of supersonic H_2/air combustion applingmodified k-ε turbulence model

为了研究超声速燃烧中流体可压缩性的影响,对标准k-ε湍流模型进行可压缩性修正(包括结构可压缩性修正和膨胀可压缩性修正两部分)。分别应用标准k-ε模型、修正的k-ε模型和雷诺应力模型(RSM),考虑氢气/空气详细化学反应机理(GR I-M ech 2.11机理,10组分,28基元反应),数值模拟有壁面限制的超声速混合层冷态及热态流场。结果表明:壁面和燃烧对湍流影响都很大;修正模型对冷态以及燃烧场的预测结果优于其它两个;修正模型预测的混合层厚度更薄,燃烧区域更窄,与实验结果吻合地更好。

To study compressibility effect in supersonic combustion, three additional terms （including structured compressibility and dilatational compressibility correction terms） were proposed to improve the standard k-ε turbulence model predictions. Combined comprehensive kinetics mechanics of H2/air （GRi-Mech 2.11,10 components, 28 reactions） , standard k-ε model, modified k-ε model and Reynolds Stress Model （RSM） were examined by simulations of wall bounded supersonic mixing layers under nonrective and reactive conditions. Comparisons of the results of the three models were made with experi- mental measurements. Both solid wall and combustion affect turbulence notably. Modified turbulence model gives better predictions than the other two models. Also the new model predicts compressed mixing layers and a narrow reaction zone, which are closer to measurements.