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g 2. 根據(jù)空調(diào)設備中常見的整體式平直翅片管尺寸結(jié)構(gòu)選取幾何模型,并使用GAMBIT 軟件對計算區(qū)域全流場及翅片內(nèi)部導熱區(qū)域進行六面體網(wǎng) 格劃分,管子周圍及流體近翅片區(qū)域采用邊界層加密處理。 10 (2) Ricardo 也對板間的流體行為進行了 3D 模擬??偟膩碚f有以下的幾種方法:一是減小換熱管的結(jié)構(gòu)尺寸,采用小管徑換熱管代替大管徑換熱管,同時減小管排橫向間距及縱向間距。對一個問題進行數(shù)值求解可以得到詳盡而完備的數(shù)據(jù)??梢姽芡獬崞膿Q熱仍然是制約換熱器效能的主要因素,因此,強化空氣側(cè)的換熱成了管翅式換熱器強化傳熱的重要問題。具體說來,就是用各種異型管取代原來的光管,現(xiàn)在較常用的有螺旋橫紋(螺紋管)、橫槽紋管、波紋管、內(nèi)翅管及管內(nèi)插入強化物質(zhì);三是換熱設備的強化與用能系統(tǒng)的優(yōu)化組合,就是說按照能量的品味逐級利用,使用能的流程處于最合理的搭配,降低能耗實 現(xiàn)全系統(tǒng)的節(jié)能。 關(guān) 鍵字 : 數(shù)值模擬;平直翅片;層流流動;流動換熱 II Numerical Study on Heat Transfer and Pressure Drop Characteristics of Plainfinned Tube ABSTRACT As plainfinned tube is an important ponent for thermal systems and refrigeration and air conditioning equipment, the study for its heat transfer performance is always a hot topics for researchers. Although its pact structure, heat transfer efficiency are lower than plate or platefin heat exchangers, plainfinned tube heat exchangers have also being widely used in the energy, chemical, oil and other industries for its many advantages which contained withstand high temperature and pressure, adptable widely, reliable, simple manufacturing, low costs and wide selection. Thus, studies for the flow and heat transfer of finned tube bundles are of great significance. Aim at the flow characteristics of plainfinned tube, this paper will study the followings: Simplely overview the study progress and present stuation of plainfinned tube,and on the basis of parative analysis the goods and bads of three research methods:experimental, analysis and numerical method. we determine use Gambitsoftware to bilud physical model for different size tube structures, and use to study the flow in the finned tube channel, then calculate the relationship between Re and Nu number,f(resistance cofficient), and analyze Re, finpitchnumber of tube rows, row spacing of fin tube(horizontal spacing and vertical spacing), the impact on the plainfinned tube39。 1 (論文)任務 書 第 1 頁 2 畢業(yè)設計(論文)題目: 平直翅片管傳熱與阻力 特性的數(shù)值研究 畢業(yè)設計(論文)要求及原始數(shù)據(jù)(資料): 畢業(yè)設計(論文)要求: (1) 了解 強化傳熱技術(shù)的發(fā)展、平直翅片管強化傳熱的機理及此換熱設備在實際中的應用 ; (2) 了解翅片管換熱與阻力性能研究進程及國內(nèi)外研究發(fā)展現(xiàn)狀 ; (3) 了解 用數(shù)值方法研究翅片管換熱問題的優(yōu)越性并掌握數(shù)值解法的基本原理 ; (4) 初步掌握 GAMBIT 軟件構(gòu)建三維模型、劃分網(wǎng)格、使用 Fluent 軟件數(shù)值求解并對實驗數(shù)據(jù)后處理分析的基本方法 ; (5) 初步培養(yǎng)嚴謹?shù)目蒲?素質(zhì)和獨立工作的能力 。s flow and heat transfer performance, so as to provide a theoretical basis for the disgn, improvement and optimization of plainfinned tude heat exchangers. Key words: numerical simulation; plainfin; laminar flow; heat transfer III 目 錄 摘 要 ...................................................................................................................................... I Abstract......................................................................................................................................II 第一章 緒論 ......................................................................................................................... 1 課題背景及研究意義 ............................................................................................. 1 翅片管強化傳熱的數(shù)值解法 ................................................................................. 4 平直翅片管換熱器的研究進展及成果 ................................................................. 7 本文的主要研究內(nèi)容 ........................................................................................... 11 第二 章 平直翅片管換熱流動模型建立與分析 ............................................................... 12 平直翅片管換熱與流動特性物理過程的描述 ................................................... 12 平直翅片管換熱器物理模型的建立 ................................................................... 12 平直翅片管數(shù)學模型描述與簡化假設 ............................................................... 14 第三章 基于 Fluent 平直翅片管數(shù)值模擬及 CFD 簡介 ................................................. 18 常用數(shù)值計算方法簡介 ....................................................................................... 18 CFD 概述 .............................................................................................................. 20 FLUENT 軟件概述及 GAMBIT 簡介 ................................................................. 22 平直翅片管基于 FLUENT 數(shù)值模擬 .................................................................. 24 第四章 平直翅片管數(shù)值計算結(jié)果及數(shù)據(jù)分析 ............................................................... 27 迭代殘差圖 ..................................