在低温下对二氧化碳旋转不弹性的碰撞进行实验室研究
C Álvarez1, G Tejeda1, J M Fernández1
1Laboratory of Molecular Fluid Dynamics, Instituto de Estructura de la Materia IEM-CSIC, C/Serrano 121, 28006 Madrid, Spain.
The Journal of chemical physics
|April 23, 2024
概括
这项研究使用拉曼光谱学研究了超音速喷射中的二氧化碳 (CO2) 旋转放松. 分析了州对州的比率,揭示了对流体动力学至关重要的温度依赖趋势.
科学领域:
- 物理化学 物理化学
- 化学物理 化学物理
- 流体动力学 流体动力学
背景情况:
- 了解分子碰撞对于化学动力学和流体动力学至关重要.
- 旋转能量转移显著影响气相反应速率和热力学特性.
- 超音速喷射为研究非平衡分子过程提供了一个独特的环境.
研究的目的:
- 为了研究二氧化碳 (CO2) 在超音速喷气中的旋转放松动态.
- 为了确定无弹性CO2-CO2碰撞的州对州 (STS) 速率系数.
- 从微观碰撞数据中推导出宏观流体动态特性.
主要方法:
- 利用具有高光谱和空间分辨率的拉曼光谱来探测超音速喷气.
- 测量了轮值人口分布和总人数密度.
- 分析了旋转群体的时间演变,使用动力主方程和能量校正的突然功率定律.
主要成果:
- 确定了 CO2 旋转放松的众多州对州 (STS) 速率系数.
- 观察到,随着温度的增加 (60-260 K) 和旋转量子数的变化增加,STS速率下降.
- 导出了关键的流体动力学参数,包括旋转碰撞数,放松截面和散装粘度.
结论:
- 这项研究提供了关于CO2在超音速流中的旋转放松机制的详细见解.
- 衍生出来的STS速率和流体动态特性对于气体流的建模和模拟非常有价值.
- 经过能量校正的突然功率定律有效地将STS速率系数与所研究的热范围联系起来.
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