轉(zhuǎn)速與壓差對(duì)迷宮密封流場(chǎng)的影響

機(jī)械設(shè)計(jì)制造及其自動(dòng)化論文，論文編號(hào):JX1136  論文字?jǐn)?shù):23980.頁(yè)數(shù):42

摘   要
 迷宮密封作為工業(yè)上常見(jiàn)的一種密封形式，具有結(jié)構(gòu)簡(jiǎn)單、對(duì)各種工業(yè)介質(zhì)適應(yīng)性強(qiáng)、使用壽命長(zhǎng)等特點(diǎn)，因此廣泛應(yīng)用于離心式壓縮機(jī)、透平膨脹機(jī)、汽輪機(jī)等機(jī)械中。但隨著葉輪機(jī)械向著高性能和大容量方向發(fā)展，密封氣流激振成為威脅機(jī)組安全運(yùn)行的主要因素之一。本文圍繞迷宮密封激振機(jī)理以及動(dòng)力特性系數(shù)的研究展開(kāi)，應(yīng)用FLUENT軟件對(duì)迷宮密封內(nèi)部流場(chǎng)進(jìn)行了深入的研究，并提出了一種計(jì)算密封動(dòng)力特性系數(shù)的方法。
 本文以GAMBIT軟件FLUENT為主要計(jì)算工具，建立了迷宮密封三維有限元模型，對(duì)邊界條件的選取和網(wǎng)格的劃分進(jìn)行了分析。并將計(jì)算得到的結(jié)果與經(jīng)驗(yàn)公式計(jì)算結(jié)果進(jìn)行了對(duì)比，模擬結(jié)果與經(jīng)驗(yàn)公式計(jì)算結(jié)果相吻合。本文對(duì)迷宮密封內(nèi)部三維流場(chǎng)進(jìn)行完整地分析，對(duì)入口總壓一定與入口靜壓一定兩種情況下的流場(chǎng)進(jìn)行了分析，比較了兩種情況下作用在轉(zhuǎn)子上的氣體力。
 此外，本文還引入用戶自定義函數(shù)(UDF)定義入口總壓，并提出了一種計(jì)算大擾度情況下迷宮密封轉(zhuǎn)子動(dòng)力特性系數(shù)的方法，將氣體力的非線性因素考慮進(jìn)去，研究了偏心、轉(zhuǎn)速以及壓差對(duì)迷宮密封動(dòng)力特性系數(shù)的影響。流體在迷宮密封內(nèi)的流動(dòng)過(guò)程，遵循流體流動(dòng)的所有控制方程。
 
關(guān)鍵詞:迷宮密封，F(xiàn)LUENT，動(dòng)力特性系數(shù)

 Labyrinth seal as a common industrial form of a seal with a simple structure, adaptability to a variety of industrial medium, and long service life, it is widely used in centrifugal compressors, turbo-expander, steam turbine and other machinery . However, with the Turbomachinery toward large-capacity high-performance and direction, air sealing unit excitation as a threat to the safe operation of one of the main factors. In this paper, the mechanism of excitation around the labyrinth seal and the coefficient of dynamic characteristics of the study started, the application of FLUENT software labyrinth seal on the internal flow field of an in-depth study and a calculation of coefficient of dynamic properties of sealing methods.
 In this paper, the main GAMBIT software FLUENT calculation tools, the establishment of the labyrinth seal three-dimensional finite element model, boundary conditions on the selection and division of grid analysis. And the calculation results with the empirical formula calculation results are compared with simulation results and empirical formula calculation results. In this paper, the internal labyrinth seal a full three-dimensional flow field analysis, the total pressure of the entrance and the entrance of a certain static pressure must both cases the flow field are analyzed and compared in both cases the role of the gas force on the rotor.
 In addition, the paper also introduces user-defined function (UDF) the definition of the entrance of the total pressure, and a degree of calculation under large disturbance rotor dynamic characteristics of labyrinth seal coefficient method to force the gas into account the non-linear factors studied bias, and speed as well as the labyrinth seal pressure on the coefficient of dynamic characteristics. Fluid in the labyrinth seal flow process, to follow all the control of fluid flow equation.
 Keywords:Labyrinth seal, FLUENT, Dynamic characteristics coefficient

目 錄
摘   要 I
Abstract II
目 錄 III
第一章  緒 論 1
1.1本論文的背景及意義 1
1.2迷宮密封簡(jiǎn)介 2
1.2.1迷宮密封工作機(jī)理 3
1.2.2迷宮密封流體激振機(jī)理 4
1.2.3密封氣體力的描述 5
1.3迷宮密封流場(chǎng)及迷宮密封轉(zhuǎn)子動(dòng)特性研究現(xiàn)狀 6
1.3.1迷宮密封實(shí)驗(yàn)研究概況 7
1.3.2迷宮密封流場(chǎng)的研究現(xiàn)狀 8
1.4計(jì)算流體力學(xué)及相關(guān)軟件簡(jiǎn)介 10
1.4.1計(jì)算流體力學(xué)簡(jiǎn)介 10
1.4.2 GAMBIT軟件簡(jiǎn)介 11
1.4.3 FLUENT軟件簡(jiǎn)介 12
第二章  迷宮密封氣體流場(chǎng)分析 13
2.1計(jì)算流體力學(xué)理論與方法 13
2.1.1控制方程 13
2.1.2湍流模型 15
2.1.3 SIMPLE算法 16
2.2邊界條件的設(shè)置及計(jì)算結(jié)果的收斂性 16
2.2.1進(jìn)出口邊界條件 16
2.2.2壁面邊界 17
2.2.3邊界條件 18
2.3本章小結(jié) 19
第三章  GAMBIT建模過(guò)程與FLUENT計(jì)算設(shè)置過(guò)程 20
3.1 GAMBIT建模過(guò)程 20
3.1.1 建密封結(jié)構(gòu)三維模型 20
3.1.2 網(wǎng)格劃分 23
3.1.3邊界設(shè)置 26
3.2 迷宮密封流場(chǎng)的計(jì)算 26
3.2.1 使用網(wǎng)格 26
3.2.2 求解器與運(yùn)算環(huán)境 26
3.2.3 確定計(jì)算模型 27
3.2.4 設(shè)置邊界條件 27
3.2.5 設(shè)置求解控制參數(shù)與迭代 27
3.3本章小結(jié) 28
第四章  計(jì)算結(jié)果的后處理與分析 29
4.1迷宮密封流場(chǎng)壓力場(chǎng)基本分析 29
4.2迷宮密封流場(chǎng)速度場(chǎng)基本分析 31
4.3轉(zhuǎn)子轉(zhuǎn)速對(duì)轉(zhuǎn)子表面周向壓力分布的影響 32
4.4壓差對(duì)轉(zhuǎn)子表面周向壓力分布的影響 32
4.5本章小結(jié) 35
致    謝 36
參 考 文 獻(xiàn) 37