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随着液体燃料费用的上升 ,排放标准更加严格 ,需要采用更经济、更有效的燃烧方法。天然气 /柴油双燃料发动机由于具有较好的排放特性 ,受到研究人员的关注。为了改善双燃料发动机的燃烧过程 ,本文采用离散型液滴模型模拟喷雾 ,采用 k- ε双方程模型模拟湍流运动 ,用多步快速反应模型模拟燃烧化学反应 ,建立了双燃料发动机二维燃烧模型 ,并采用任意拉格朗日 -欧拉法对得到的偏微分方程组进行离散求解。对一台单缸双燃料发动机进行了模拟计算 ,将计算结果与实验结果对比分析发现 ,计算结果与实验结果吻合较好 ,表明本文的数值计算正确地反映了缸内燃烧过程的实际规律 ,能够反映引燃油量、发动机转速与负荷等运行参数对发动机燃烧过程的影响。因而该模型对于进一步优化双燃料发动机的动力性、经济性和排放特性 ,揭示影响其燃烧的主要因素具有重要价值。
As liquid fuel costs rise, emission standards become more stringent, requiring more cost-effective and efficient combustion methods. Natural gas / diesel dual-fuel engines have attracted the attention of researchers because of their good emission characteristics. In order to improve the combustion process of the dual-fuel engine, a discrete droplet model was used to simulate the spray. The k-ε two-equation model was used to simulate the turbulent flow and the multi-step rapid reaction model was used to simulate the combustion reaction. The two- , And discretized the partial differential equations obtained by using arbitrary Lagrange-Euler method. A single-cylinder dual-fuel engine was simulated. Comparing the calculated results with the experimental results, it was found that the calculated results agree well with the experimental results, indicating that the numerical calculation in this paper correctly reflects the actual law of the combustion process in the cylinder. Reflects the ignition fuel, engine speed and load and other operating parameters of the engine combustion process. Therefore, the model is of great value to further optimize the dynamic, economical and emission characteristics of dual-fuel engines and to reveal the main factors affecting their combustion.