Supercontinuum based absorption spectrometer for cycle-resolved multiparameter measurements in a rapid compression machine
Supercontinuum based absorption spectrometer for cycle-resolved multiparameter measurements in a rapid compression machine
复制标题
DOI：
10.1364/ao.55.004564
复制
发表时间：
2016-06-10
期刊：
影响因子：
1.9
通讯作者：
Will, Stefan
中科院分区：
文献类型：
--
作者：
Werblinski, Thomas;Kleindienst, Stefan;Will, Stefan
介绍了一种基于宽带超连续谱（SC）的内燃机多参数循环分辨吸收光谱仪。三个参数，温度，压力和水的摩尔分数，从宽带近红外H2O吸收光谱中提取，跨越波长范围从1340到1405.5 nm，其中表现出大量的特定H2O跃迁。光谱仪是基于空间域检测和功能的近红外线扫描相机作为探测器。在快速压缩机的压缩循环期间进行测量，所述快速压缩机包括分别从2.5至65巴和300至900 K的压力和温度范围。借助新的光谱仪，我们首次能够根据作者的知识，以高达50 kHz的测量速率在完整的压缩和膨胀冲程中进行基于SC辐射的测量。详细介绍了理论和实验之间的最佳匹配算法，包括两个不同的光谱数据库，即Barber-Tennyson数据库（BT 2）和HITRAN 2012的参数。结果表明，光谱增宽效应没有正确的理论描述，特别是在压力水平超过20巴，这最终在一个明确的低估所得出的压力数据SC吸收光谱。然而，温度可以通过基于水摩尔分数、温度和压力执行三参数拟合来精确地确定。相比之下，利用压力传感器数据作为查找值并且仅改变温度和H2O摩尔分数以找到最佳匹配导致在升高的压力下对温度的明显高估。(C)2016美国光学学会
A broadband supercontinuum (SC) based absorption spectrometer capable of cycle-resolved multiparameter measurements at internal combustion (IC) engine conditions is presented. Three parameters, temperature, pressure and water mole fraction, were extracted from broadband near-infrared H2O absorption spectra, spanning the wavelength-range from 1340 to 1405.5 nm, which exhibits a large number of specific H2O transitions. The spectrometer is based on spatial domain detection and features a near-infrared line scan camera as a detector. Measurements were performed during a compression cycle of a rapid compression machine comprising a pressure and temperature range from 2.5 to 65 bar and 300 to 900 K, respectively. With the new spectrometer, we are for the first time, based on the authors' knowledge, able to perform measurements based on SC radiation over a complete compression and expansion stroke at measurement rates up to 50 kHz. A detailed overview is provided about the best match algorithm between theory and experiments, including parameters from two different spectral databases, namely the Barber-Tennyson database (BT2) and HITRAN2012. The results indicate that spectral broadening effects are not properly described by theory, especially at pressure levels exceeding 20 bar, which culminates in a clear underestimation of the derived pressure data by SC absorption spectroscopy. Nevertheless, temperature can be determined accurately by performing a three-parameter fit based on water mole fraction, temperature, and pressure. In contrast, making use of pressure transducer data as look-up values and varying only temperature and H2O mole fraction to find the best match leads to a clear overestimation of temperature at elevated pressures. (C) 2016 Optical Society of America