【作者】 王媛媛；

【导师】 孙海鸥；

【作者基本信息】 哈尔滨工程大学 ， 流体机械及工程， 2008， 硕士

【摘要】 因效率高、功率大、重量轻、尺寸小、机动性好等优点,燃气轮机成为大中型水面舰船的主动力装置。船舶燃气轮机以空气为工作介质,在海洋环境条件下,空气中含有大量的盐雾颗粒以及油污、沙尘等杂质,这些都会对燃气轮机造成危害。为了保证在海洋环境条件下运行的燃气轮机的性能和可靠性,绝大多数舰艇都装备有进气滤清装置。因此对燃气轮机进气滤清器进行数值模拟及实验研究具有重要的现实意义,能为高性能船用进气滤清器的设计制造提供有力的依据。本文所研究的旋风级(由顺序排列的多个旋风子构成)是组合式滤清器中的第一级,它能够起到缓减波浪对后级滤清器的冲击、快速疏水以及分离大直径液滴的作用,是组合式滤清器不可缺少的一个重要组成部分。旋风子的两个主要指标是阻力和分离效率,本文通过数值模拟与实验研究相结合的方法对其进行研究,主要进行了如下几个方面的工作:1.对现有旋风子模型采用结构化网格进行数值模拟,考查其阻力特性,分析其内部流场分布情况,并且以降低阻力为目标而进行改型设计。通过在旋风子出气口处加装扩压段,达到降低阻力的目的。2.采用非结构化网格对旋风子原型和改进型进行数值模拟,并同结构化网格数值模拟结果进行对比分析。结果显示,对于旋风子来说,采用两种结构不同的网格,其数值模拟结果基本一致。3.考虑到旋风级的实际情况,采用周期性边界条件对旋风子原型和改进型进行单相数值模拟,之后进行了两相流的数值模拟。两相流计算的结果表明,旋风子捕捉大颗粒的效果更好。4.利用小型风洞对旋风子进行阻力和效率的实验研究,对数值模拟结果加以验证。阻力实验易于实现,实验结果验证了数值模拟的准确性;对于分离效率实验,借助附加装置形成组合滤清器来获得系统的分离效率特性。更多还原

【Abstract】 Because of the advantages of high efficiency, great power, small volume, lightness, good flexibility and so on, marine gas turbine has become the main power plant of large and middle sized marine warship. Marine gas turbine uses air as working medium. The air in the marine environment always sustains large numbers of salt particles, smear and sand-dust, which will harm the gas turbine. In order to ensure the performance and reliability of the marine gas turbine, most naval ships use the filter system. So investigating the mechanism of the air-intake filter installation in the gas turbine by using numerical simulation method and experimental method has important realistic significance of providing relative reference to the design and manufacture of the marine air-intake filter installation.In this article, the object of study is a cyclone stage which is combined by some serial cyclone separators. As the first stage of the combinational filter with high efficiency, cyclone stage can mitigate wave impact to the back stage of the filter; fleetly drain off the water and separate large diameter droplet. It is one of the most important parts of the combinational filter. Two main characteristics of the cyclone separator are the resistance and the separation efficiency. In this article, using the method of combining numerical simulation with experimental research to investigate the cyclone separator, some works have been done as followed:Firstly, applying structural grid to simulate the original model of cyclone separate, studying its resistance characteristic, analyzing the distributing situation of the inner flow field in the cyclone separator; and making relative design to reduce the resistance. Through installing diffuser on the gas outlet of the cyclone separator to reach the purpose of reducing the resistance;Secondly, applying unstructured grid to simulate the antetype model and the modified model of the cyclone separator; comparing with the results of structural grid model and making relevant analysis. The results show that, the numerical simulation results of two different grids are nearly the same for the cyclone separator;Thirdly, considering the actual condition of the cyclone stage, applying the periodicity boundary condition to investigate the antetype and the modified model of the cyclone separator by using single-phase numerical simulation method, then simulating two-phase flow field. The results of two-phase flow field simulation indicate that the effect of catching big granules is better for the cyclone separator;Finally, using pint-sized wind tunnel to carry out resistance experiment and efficiency experiment of the cyclone separator in order to validate the numerical simulation results. The resistance experimentalize is easily achieved, and the results validate the veracity of the numerical simulation results of resisitance characteristics; For the efficiency experiment, by dint of additive equipments to form combined filter, then obtain the separate efficiency characteristics of the system.更多还原