在层状甲火焰中使用红外四波混合技术进行温度和热扩散性诊断
Zihao Song1,2,3, Xing Chao3, Anna-Lena Sahlberg2
1School of Aerospace Engineering, Tsinghua University, Beijing, China.
Applied spectroscopy
|February 27, 2024
概括
这项研究结合了激光诱导光谱学 (LIGS) 和退化四波混合 (DFWM) 进行精确的燃烧诊断. 双重技术准确地测量了各种燃料空气混合物的火焰温度和热力学特性.
科学领域:
- 燃烧诊断仪器的使用
- 激光光谱学 激光光谱学
- 测温仪测温仪是用来测温的.
背景情况:
- 由于高S/N,连贯信号和空间分辨率,四波混合技术如CARS,LIGS和DFWM对于燃烧诊断非常有价值.
- 精确测量火焰温度和热力学特性对于燃烧研究和模拟至关重要.
研究的目的:
- 为了证明LIGS和DFWM的结合测量在预混合层状CH4 / O2 / N2火焰中进行精确的温度计.
- 为了在广泛的等效比率 (0.6到1.5) 中实现准确的温度测量.
- 为了提取其他热力学参数,如声音速度和热扩散率.
主要方法:
- 利用纳米秒脉冲激光器产生中红外束 (近3微米) 来激发水的振动过渡.
- 采用LIGS用于燃料稀缺火焰和DFWM用于燃料丰富的火焰,利用LIGS进行DFWM校准.
- 将理论模型应用于LIGS信号时间波形,以提取声音速度和热扩散率.
主要成果:
- 在低燃油火焰中,LIGS的温度精度超过16K (0.8%).
- 在富含燃料的火焰中,DFWM在燃料丰富的火焰中获得了超过90K (4.5%) 的温度精度,弥补了气体成分的不确定性.
- 提取的局部音速和热扩散率的精度分别优于0.5%和1.3%.
结论:
- 结合LIGS和DFWM的方法在广泛的火焰条件下提供了准确的温度计.
- 这种双技术方法为准确诊断火焰中的热力学参数提供了潜在的潜力.
- 高精度测量为火焰研究和计算流体动力学模拟提供了有价值的数据.
相关概念视频
Flame Photometry: Overview
589
Flame photometry, also known as flame emission spectrometry, is a technique used for the qualitative and quantitative analysis of elements present in a sample using a flame as the source of excitation energy. The concept of flame photometry was realized in the early 1860s by Kirchhoff and Bunsen, who discovered that specific elements emit characteristic radiation when excited in flames. The first instrument developed for this purpose was used to measure sodium (Na) in plant ash using a Bunsen...
589
Flame Photometry: Lab
246
In a flame photometer, when a solution like potassium chloride is aspirated into the flame, the solvent evaporates, leaving behind dehydrated salt. This salt dissociates into free gaseous atoms in their ground state. Some of these atoms absorb energy from the flame, leading to their excitation. The excited atoms return to the ground state, emitting photons at characteristic wavelengths. Because only electronic transitions are involved, the resulting emission lines are very narrow. The intensity...
246
Gas Chromatography: Types of Detectors-I
426
There are different types of detectors used in gas chromatography, each with its own specific properties that make it suitable for detecting certain types of analytes. The most commonly used detectors in GC are thermal conductivity detector (TCD), flame ionization detector (FID), and electron capture detector (ECD).
TCD is the earliest and most widely used detector that operates by measuring the changes in the thermal conductivity of the carrier gas. When a sample compound enters the detector,...
TCD is the earliest and most widely used detector that operates by measuring the changes in the thermal conductivity of the carrier gas. When a sample compound enters the detector,...
426
IR Spectrometers
1.2K
There are two main infrared (IR) spectrophotometers: dispersive IR spectrometers and Fourier transform infrared (FTIR) spectrometers. In a dispersive IR spectrometer, a beam of infrared radiation produced by a hot wire is divided into two parallel equal-intensity beams using mirrors. One beam passes through the sample, while another is a reference beam. The beams then move through the monochromator, which separates the radiations into a continuous spectrum of different frequencies. The...
1.2K
Gas Chromatography: Types of Detectors-II
371
In gas chromatography, different detectors are employed to meet specific analytical needs. These detectors are often categorized based on their detection mechanisms and the types of compounds they are best suited to analyze. Thermal Conductivity Detectors (TCD), Flame Ionization Detectors (FID), and Electron Capture Detectors (ECD) represent common categories, each with unique operating principles and applications. However, beyond these, several other detectors are designed for more specialized...
371


