Investigation and Application of Fundamental Phenomena of Turbulent Premixed Combustion in a High-Pressure Environment

高压环境下湍流预混燃烧基本现象的研究与应用

• 批准号: 10450079
• 负责人: KOBAYASHI Hideaki
• 金额: $ 4.99万
• 依托单位: TOHOKU UNIVERSITY
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (B)
• 财政年份: 1998
• 资助国家: 日本
• 起止时间: 1998 至 1999
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-10450079/
• 关键词: High-Pressure Combustion; Turbulent Combustion; LIF; Turbulent Burning Velocity; Instability; Fractal; Cut-off Scale; 予混合燃焼; OHラジカル; 吸収スペクトル; High-Pressure Combustion; Turbulent Combustion; LIF; Turbulent Burning Velocity; Instability; Fractal; Cut-off Scale; 予混合燃焼; OHラジカル; 吸収スペクトル

Turbulent premixed flames stabilized in a high-pressure atmosphere was studied with the aim of basic elucidation of phenomena of the high-pressure turbulent combustion which has not been explored precisely. The relationship between turbulence characteristics and turbulent flame structure under high pressure was clarified. Investigation of pressure effect for the fractal properties and turbulent burning velocity under high pressure were also made.The laminar flow nozzle-burner is installed in the pressure chamber, and OH-LIF technique were investigated at pressures from the atmospheric pressure up to 3.0 MPa. (0, 0) band and (1, 0) band of the OH radical were excited by an OPO tunable laser and a dye laser pumped by a Nd-YAG laser. The relationship between OH-LIF intensity and pressure was examined. In addition, a simulation considering effects of the broadening of laser line width and absorption spectrum was made and also compared with the experimental result. As the result, it was cla … More rified that the effects of the absorption spectrum broadening was large for the LIF intensity degradation with the increase in pressure. Although the LIF intensity for larger laser line width is smaller than the case of smaller laser line width at atmospheric pressure, the decrease in LIF intensity with pressure is small for larger laser line width. It was proven that to estimate LIF intensity degradation under the high pressure was possible by calculating the overlap integral of laser spectrum profiles and absorption line spectral profiles. From these findings, guideline for the measurement condition of OH-PLIF at high-pressure was established.In continuing, the OH-PLIF method was applied to the instantaneous tomographic imaging of high-pressure turbulent flames. Especially, the fractal analysis of the OH-PLIF image was carried out as the technique which can quantitatively evaluate refinement and complication of the turbulent flame structure. As the result, it was proved that the fractal dimension for high-pressure flame was larger than atmospheric pressure flame even for equal u'/SィイD2LィエD2. The fractal inner cutoff decreased with pressure, but it was proven that the fractal inner cutoff was almost fixed in almost whole range of u'/SィイD2LィエD2 at high pressure. When various characteristic scales such as turbulent scales were compared with the fractal inner cutoff, it was proved that a characteristic instability scale, which corresponds to disturbance scale of maximum growth rate for the hydrodynamic instability, was well correlated to the fractal inner cutoff. These new findings which the hydrodynamic instability has dominant effects at high pressure were also confirmed by the observation of the flame instability with no initial turbulence in flow at high pressure. Less

研究了在高压大气中稳定的湍流预混合火焰，目的是基本阐明高压湍流组合现象的基本化，这尚未精确地探索。阐明了高压下的湍流特性与湍流结构之间的关系。还对分形性质的压力效应和高压下的湍流燃烧速度进行了研究。层状流量燃烧器安装在压力室中，OH-LIF技术在从大气压力到3.0 MPa的压力下进行了研究。 （0，0）OH激进分子的频带和（1，0）频带被ND-YAG激光器泵送的Opo可调激光和染料激光激发。检查了OH-LIF强度和压力之间的关系。此外，制定了模拟考虑激光线宽度和滥用光谱的效果，并与实验结果进行了比较。结果，是CLA…更加夸张的是，随着压力的增加，抽象谱扩展的影响很大。尽管在大气压力下，较大激光线宽度的LIF强度小于较小的激光线宽度的情况，但随着压力的LIF强度降低，对于较大的激光线宽度而言，LIF强度较小。事实证明，通过计算激光光谱曲线和抽象线光谱曲线的重叠积分，可以在高压下估计LIF强度降解。从这些发现中，建立了高压下OH-PLIF的测量条件的指南。在继续，将OH-PLIF方法应用于高压湍流火焰的瞬时层析成像。特别是，对OH-PLIF图像的分形分析是作为可以定量评估湍流火焰结构的细化和并发症的技术进行的。结果，证明高压火焰的分形尺寸即使对于相等的u'/sii d2lie d2也大于大气压火焰。分形内临界值随压力下降，但事实证明，分形内截止几乎在高压下几乎固定在U'/sii d2lie D2的整个范围内。当将各种特征性量表（例如湍流尺度）与分形内截止进行比较时，证明特征不稳定性量表与流体动力学不稳定性的最大生长速率相对应，与分形内部截止良好相关。通过观察火焰不稳定的观察，流体动力不稳定在高压下具有显着作用的新发现，而高压下流量没有初始湍流。较少的