A predictive three-dimensional Eulerian−Lagrangian framework for ammonia spray is suggested, and its evolution characteristics under both normal evaporating and superheated conditions are unraveled. First, a simplified boundary model considering the effects of superheated fluid behaviors within the nozzle on the injection velocity and angle was proposed. The real vapor−liquid equilibrium theory is applied in the evaporation model to improve the prediction accuracy of the phase change. An explosion model with the homogenous nucleation theory was used to simulate the burst process. Then, the spray experiment for the liquid ammonia under varied conditions was conducted, and the high-speed diffused back illumination and schlieren approaches were adopted to measure the spray evolutions. Following that, the simulation results were verified against the experimental data under both normal evaporating and superheated conditions, and good agreements indicated that the suggested framework was feasible to accurately and efficiently simulate the evolutions and morphology of ammonia spray. Finally, the transient evolution characteristics of ammonia spray under various conditions were discussed. The heavy cooling effect of ammonia evaporation makes the initial fuel temperature have a notable effect on its spray penetration and expansion.

中文翻译：

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正常蒸发和过热条件下氨喷雾的模拟

提出了氨喷雾的预测三维欧拉-拉格朗日框架，并揭示了其在正常蒸发和过热条件下的演化特征。首先，提出了考虑喷嘴内过热流体行为对喷射速度和角度影响的简化边界模型。蒸发模型中应用真实的气液平衡理论，提高了相变的预测精度。采用均相成核理论的爆炸模型来模拟爆炸过程。然后，进行了不同条件下液氨的喷雾实验，采用高速漫反射背照法和纹影法测量了喷雾的演变过程。跟随那个，模拟结果与正常蒸发和过热条件下的实验数据进行了验证，良好的一致性表明所提出的框架可以准确有效地模拟氨喷雾的演变和形态。最后讨论了不同条件下氨喷雾的瞬态演化特征。氨蒸发的强烈冷却作用使得燃料初始温度对其喷雾穿透和扩展有显着影响。讨论了不同条件下氨喷雾的瞬态演化特征。氨蒸发的强烈冷却作用使得燃料初始温度对其喷雾穿透和扩展有显着影响。讨论了不同条件下氨喷雾的瞬态演化特征。氨蒸发的强烈冷却作用使得燃料初始温度对其喷雾穿透和扩展有显着影响。