光电工程, 2011, 38 (3): 58, 网络出版: 2011-04-01
MGDL主喷管中氮气第一振动能级冻结效率
Freezing Efficiency of N2(v=1) Vibrational Level in Donor Nozzle of MGDL
混合型气动CO2 激光器 N2(v=1)振动能级 能量转移过程 冻结效率 mixing gasdynamic CO2 laser N2(v=1) vibrational level energy transfer process freezing efficiency
摘要
传统的气动CO2 激光器计算方法一直基于弛豫动力学, 本文将混合型气动CO2 激光器(简称MGDL)主喷管中的能量转移过程当作化学反应来处理, 采用化学反应动力学的方法对N2(v=1)振动能级的冻结效率进行了研究。根据文献中给出的正向反应速率常数, 求解了逆向反应速率常数。研究了N2(v=1)分子在MGDL 主喷管中的分布及总压和含水量对N2(v=1)振动能级冻结效率的影响。计算结果表明:N2(v=1)分子质量分数的减少主要发生在喷管喉部及其附近区域;与不含水的情形相比较, 含水时N2(v=1)振动能级的冻结效率明显降低;总压升高时, N2(v=1)振动能级的冻结效率下降, 但下降幅度很小;相比较, 随着含水量的增加, N2(v=1)振动能级的冻结效率下降较快。
Abstract
The calculation method of conventional gasdynamic CO2 laser is always based on relaxation dynamics. In the paper, energy transfer processes in donor nozzle of mixing gasdynamic CO2 laser(MGDL) are treated as chemical reactions and freezing efficiency of N2(v=1) vibrational level is studied by using method of chemical reaction kinetics. Using forward reaction rate constants given by other papers, the backward reaction rate constants are calculated. Distribution of N2 (v=1) molecules in donor nozzle of MGDL and influences of total pressure and molar fraction of H2O on freezing efficiency of N2(v=1) vibrational level are studied. The results indicate that decrease of mass fraction of N2(v=1) molecules happens mainly in and around the nozzle throat. Compared with the case of not containing H2O, the freezing efficiency of N2 (v=1) vibrational level decreases remarkably while containing H2O. When total pressure increases, the freezing efficiency of N2(v=1) vibrational level decreases, but just a little. Comparatively, with increasing of molar fraction of H2O, the freezing efficiency of N2 (v=1) vibrational level decreases rapidly.
翟小飞, 周进, 赖林. MGDL主喷管中氮气第一振动能级冻结效率[J]. 光电工程, 2011, 38(3): 58. ZHAI Xiao-fei, ZHOU Jin, LAI Lin. Freezing Efficiency of N2(v=1) Vibrational Level in Donor Nozzle of MGDL[J]. Opto-Electronic Engineering, 2011, 38(3): 58.