| 题名 | 传热、燃烧过程中声波作用的机理研究 |
| 作者 | 朱永波 |
| 学位类别 | 博士 |
| 答辩日期 | 2001 |
| 授予单位 | 中国科学院声学研究所 |
| 授予地点 | 中国科学院声学研究所 |
| 关键词 | 热声学 振荡燃烧 噪声控制 模态分析方法 |
| 其他题名 | machanism of interaction between sound and heat, combustion |
| 中文摘要 | 在发动机的燃烧室内,如果传热与声波的相位满足一定条件,声场与传热、燃烧间会相互耦合,产生很强的振荡.这种振荡可能使发动机熄火,甚至引起结构部件破坏.该文的工程背景是探讨振荡燃烧的机理,并研究如何抑制振荡燃烧.在机理研究方面,结合燃烧学和声学理论推导了火焰微团噪声辐射的解析描述.表明传热速度等参数对火焰微团噪声有很复杂、非线性的影响,另外研究了计算火焰噪声的数值方法.为了研究如何抑制振荡噪声,该文根据发动机结构特点,首先采用模态分析方法计算了多段声衬降噪情况下的声场;然后又开发了一种管束式穿孔板共振吸声结构.这种吸声结构的吸声效果优于普通微穿孔板,而且在工程上特点适合发动机降噪.以Rijke管为简化模型,实验研究了Rijke管中对发声频谱、声压的影响,以及Rijke管瞬态发声特性.实验表明Rijke管内有很强烈的非线性现象.采用模态分析方法,分析了Rijke管控制方程的稳定性;与实验结果定性符合. |
| 英文摘要 | Self-excited thermo-acoustic instabilities or oscillations can occur in confined geometries. It results from a feedback loop between the heat transferred to the fluid from a heat source and the acoustics of the geometry. If the heat input is at times of high pressure, a self-amplification of acoustic fluctuations may lead to high pressure amplitudes.The aim of this study is to investigate the mechanism of unsteady combustion and how to control this kind of noise in engine. Besides this, some relative thermo-acoustic problems are also discussed. To investigate the interaction between sound and combustion, the analysis solutions of sound emitted by a micro-flame is provided by combining the combustion and acoustics. It shows that there is a complicated, nonlinear relation between the sound pressure and combustion parameters. According to engine structure, the modal analysis is applied to investigation on the sound propagation in a straight circular duct with multi-segmented acoustical treatments. And the prediction model of sound propagation in the presence of uniform flow and shear flow is established. An innovative sound absorbing structure, which is suitable to reduce engine noise, the perforated panel with flexible tube bundle has been introduced. Its absorption is much better than that of traditional perforated panel absorber. To investigate the principle of thermo-acoustic interaction, a series of experiments on a Rijke tube are studied. The influence of parameters such as heat source location and temperature on the sound pressure and frequency in Rijke tube is provided. The results show that the acoustic change in Rijke tube can be highly nonlinear. The modal analysis is used to study the stability of control equations, and the results agree with experimental data qualitatively. |
| 语种 | 中文 |
| 公开日期 | 2011-05-07 |
| 页码 | 97 |
| 内容类型 | 学位论文 |
| 源URL | [http://159.226.59.140/handle/311008/806]  |
| 专题 | 声学研究所_声学所博硕士学位论文_1981-2009博硕士学位论文 |
| 推荐引用方式 GB/T 7714 | 朱永波. 传热、燃烧过程中声波作用的机理研究[D]. 中国科学院声学研究所. 中国科学院声学研究所. 2001. |
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