通信：在与 Ar(S) 的碰撞中，CO(Σ)的振动弛豫在与高超音速飞行环境相关的温度下。

Communication: Vibrational relaxation of CO(Σ) in collision with Ar(S) at temperatures relevant to the hypersonic flight regime.

机构信息

Department of Chemistry, University of Basel, Klingelbergstrasse 80, CH-4056 Basel, Switzerland.

Air Force Research Laboratory, Space Vehicles Directorate, Kirtland AFB, New Mexico 87117, USA.

出版信息

J Chem Phys. 2017 Mar 21;146(11):111102. doi: 10.1063/1.4978498.

DOI:10.1063/1.4978498

PMID:28330359

Abstract

Vibrational energy relaxation (VER) of diatomics following collisions with the surrounding medium is an important elementary process for modeling high-temperature gas flow. VER is characterized by two parameters: the vibrational relaxation time τ and the state relaxation rates. Here the vibrational relaxation of CO(ν=0←ν=1) in Ar is considered for validating a computational approach to determine the vibrational relaxation time parameter (pτ) using an accurate, fully dimensional potential energy surface. For lower temperatures, comparison with experimental data shows very good agreement whereas at higher temperatures (up to 25 000 K), comparisons with an empirically modified model due to Park confirm its validity for CO in Ar. Additionally, the calculations provide insight into the importance of Δν>1 transitions that are ignored in typical applications of the Landau-Teller framework.

摘要

双原子分子与周围介质碰撞后的振动能量弛豫（VER）是模拟高温气流的重要基本过程。VER 由两个参数描述：振动弛豫时间 τ 和状态弛豫速率。此处考虑了 CO（ν=0←ν=1）在 Ar 中的振动弛豫，以验证一种使用精确的全维势能面确定振动弛豫时间参数（pτ）的计算方法。对于较低的温度，与实验数据的比较显示出非常好的一致性，而在较高的温度（高达 25000 K）下，与由于 Park 提出的经验修正模型的比较证实了其在 Ar 中对 CO 的有效性。此外，计算结果深入了解了在 Landau-Teller 框架的典型应用中被忽略的Δν>1 跃迁的重要性。