基于CFD的迷宮密封流場計算

機械設計制造及其自動化論文，論文編號:JX1154  論文字數:14016.頁數:32

 摘要
   迷宮密封作為工業上常見的一種非接觸式密封，具有結構簡單、對各種工業介質適應性強、使用壽命長等特點。主要應用于離心壓縮機、透平膨脹機、汽輪機等機械中。隨著葉輪機械向高性能和大容量方向發展，密封氣流激振成為威脅機組安全運行的主要因素之一。本文應用CFD軟件Fluent對迷宮密封氣流激振力以及密封轉子動力特性系數進行研究。
 建立起迷宮密封三維有限元模型，對邊界條件的選取進行分析。針對網格劃分，研究了網格數的選取和計算結果的關系。將計算得到的泄漏量與經驗公式計算結果比較，結果表明模擬結果和經驗公式計算結果比較吻合。
 最后，基于前面的研究，研究影響動力特性和泄漏量的因素。
 
關鍵詞： 迷宮密封 Fluent 氣流激振力 動力特性系數

Abstract
 As one of the common non-contact seals used in the industry, labyrinth seal has the distinguishing features of simple configuration, strong applicability for multifarious industrial medium and long service life. It's widely used in revolving compressor and turbo-machinery. However with the development of turbo-machinery towards high performance and huge capacity, gas excitation vibration within the labyrinth seal becomes the main reason threatening the safe operating of machinery sets. This paper applied the CFD software FLUENT to study the forces resulted from gas exciting vibration and the dynamic coefficients of labyrinth seals.
 Three-dimensional finite element model of labyrinth seal was established, the selection of boundary conditions in this model was analysed. Meanwhile the fluence of grid units to the simulating results was studied. The leakage computed from the simulation and from experiential formulas were compared and showed similar results.
 
Keywords: Labyrinth seal  FLUENT  Gas excitation force  Dynamic coefficients

目   錄
摘要…………………………………………………………………………………Ⅰ
Abstract……………………………………………………………………………Ⅱ
目錄…………………………………………………………………………………Ⅲ
  緒論………………………………………………………………………1
 1.1迷宮密封簡介……………………………………………………………1
1.2迷宮密封研究……………………………………………………………1
  1.2.1基礎理論……………………………………………………………1
  1.2.2數值研究進展………………………………………………………2
1.3課題背景…………………………………………………………………3
1.4為什么選用Flunet…………………………………………………… 4
第二章  GAMBIT建模過程與FLUENT計算設置過程……………………………5
     2.1 GAMBIT建模過程……………………………………………………… 5
      2.1.1建密封結構三維模型………………………………………………5
 2.1.2網格劃分……………………………………………………………8
 2.1.3邊界設置……………………………………………………………11
 2.2迷宮密封流場的計算……………………………………………………11
   2.2.1使用網格……………………………………………………………11
 2.2.2求解器與運算環境…………………………………………………11
 2.2.3確定計算模型………………………………………………………12
 2.2.4設置邊界條件………………………………………………………12
 2.2.5設置求解控制參數與迭代…………………………………………12
 2.3本章小結…………………………………………………………………13
第三章  計算結果的后處理與分析………………………………………………14
 3.1迷宮密封壓力流場基本分析……………………………………………14
 3.2網格相關性研究…………………………………………………………16
   3.2.1泄漏量的校核經驗公式選用………………………………………16
   3.2.2網格相關性分析……………………………………………………18
 3.3氣體力和泄漏量的影響因素分析………………………………………24
   3.3.1偏心的影響…………………………………………………………24
   3.3.2速度的影響…………………………………………………………25
第四章  總結………………………………………………………………………27
致謝…………………………………………………………………………………28
參考文獻……………………………………………………………………………29