Decoupling multimode vibrational relaxations in multi-component gas mixtures： Analysis of sound relaxational absorption spectra

• Published in: Chinese physics B Vol. 22; no. 1; pp. 328 - 337
• Main Author: 张克声 王殊 朱明 丁毅 胡轶
• Format: Journal Article
• Language: English
• Published: 2013
• Subjects: Absorption spectra; Computer simulation; Decoupling; Gas mixtures; Joining; Mathematical analysis; Mathematical models; Sound; Spectra; 吸收光谱; 声音; 多模; 多组分; 振动弛豫; 松弛; 气体混合物; 解耦模型
• ISSN: 1674-1056; 2058-3834; 1741-4199
• DOI: 10.1088/1674-1056/22/1/014305

Decoupling the complicated vibrational-vibrational （V-V） coupling of a multimode vibrational relaxation remains a challenge for analyzing the sound relaxational absorption in multi-component gas mixtures. In our previous work [Acta Phys. Sin. 61 174301 （2012）], an analytical model to predict the sound absorption from vibrational relaxation in a gas medium is proposed. In this paper, we develop the model to decouple the V-V coupled energy to each vibrationaltranslational deexcitation path, and analyze how the multimode relaxations form the peaks of sound absorption spectra in gas mixtures. We prove that a multimode relaxation is the sum of its decoupled single-relaxation processes, and only the decoupled process with a significant isochoric-molar-heat can be observed as an absorption peak. The decoupling model clarifies the essential processes behind the peaks in spectra arising from the multimode relaxations in multi-component gas mixtures. The simulation validates the proposed decoupling model.