基于大涡模拟的液氨喷雾雾化与相变特性模拟
Large eddy simulation of atomization and phase change characteristics of liquid ammonia spray
当前在能量转换装置中，由于液氨燃烧不会产生温室气体的排放，因此液氨作为燃料展示出了非常有吸引力的前景。然而，由于其独特的物理性质，液氨的雾化和相变特性与普通碳氢燃料有很大不同，这使得使用流行的欧拉-拉格朗日框架来精确模拟广泛环境条件下的氨喷雾非常具有挑战性。为此，首先考虑液滴的非球形效应模拟氨喷雾液滴的阻力和相变特性，因为氨喷雾液滴具有低表面张力。其次，建立了一个新的雾化模型来预测闪沸引起的热破碎，其中液滴内气泡的成核和生长用最新的理论来模拟。采用大涡模拟(LES)的湍流闭合模型进行了模拟，并与典型的非闪蒸和闪蒸条件下的实验数据进行了验证。结果表明，新模型与非闪蒸和闪蒸条件下的测量结果吻合较好。
The use of liquid ammonia as fuel in energy conversion devices shows attractive perspectives as it does not generate greenhouse gas emissions. However, the atomization and phase change characteristics of liquid ammonia are significantly different from common hydrocarbon fuels due to its unique physical properties, making accurate simulation of ammonia spray under wide ambient conditions very challenging using the popular Euler−Lagrange framework. To this end, firstly, the droplet non-sphericity effects are considered to mimic drag force and phase change characteristics of ammonia spray droplets owing to its low surface tension. And secondly, a new atomization model was developed to predict thermal breakup caused by flash boiling in which the nucleation and growth of bubbles within liquid droplets are modeled by the latest theories. The simulations were conducted with turbulence closure models of large-eddy simulation (LES), and the results were validated against experimental data under typical non-flash and flash boiling conditions. The results indicates that the new model shows better agreement with the measurements under non-flash and flash boiling conditions.
褚晨涛;张延志;贾明;
大连理工大学 能源与动力学院,大连 116000;大连理工大学 能源与动力学院,大连 116000;大连理工大学 能源与动力学院,大连 116000;
TU4
液氨喷雾 非球性效应 闪沸 相变 大涡模拟 OpenFOAM
ammonia spray non-sphericity effects flash boiling phase change large eddy simulation OpenFOAM
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