分子动力学研究微观拉瓦尔喷嘴的声波地平线
Helmut Ortmayer1,2, Robert E Zillich1
1Institute for Theoretical Physics, <a href="https://ror.org/052r2xn60">Johannes Kepler University</a>, 4040 Linz, Austria.
Physical review. E
|July 18, 2024
概括
微观的Laval喷嘴将气体加速到超音速,并冷却它,类似于大型喷嘴. 模拟显示了一个声波地平线,一个超出气体流不受上游条件的影响的点,即使是在纳米级.
科学领域:
- 流体动力学 流体动力学
- 热力学是一种热力学.
- 计算物理学的计算物理.
背景情况:
- 岩喷嘴加速并冷却膨胀的气体到超音速的速度.
- 了解微和纳米尺度设备中的气体动力学对于技术进步至关重要.
研究的目的:
- 在微观的拉瓦尔喷嘴中研究气体膨胀过程.
- 在纳米尺度上分析热力学特性和流动特征.
主要方法:
- 没有平衡的静止流动分子动力学模拟.
- 大法典的蒙特卡洛粒子储用于流体模拟.
- 热力学变量,克努森数和马赫数的分析.
主要成果:
- 微观的Laval喷嘴表现出超音速加速和冷却,类似于宏观的喷嘴.
- 在小喷嘴中观察到异型温度和趋向于凝结的趋势.
- 确定了一个声波地平线,与宏观的异中热扩张相比,它稍微下游发生.
结论:
- 微观的Laval喷嘴在质量上与其宏观的对应物一样.
- 声波地平线是微观尺度上一个明确的现象.
- 上游相关性在显微喷嘴流中消失在声波地平线之后.
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