【正文】 摘 要 I 論文題目：粒子追蹤測(cè)速（ PTV）算法設(shè)計(jì)與編程實(shí)現(xiàn) 學(xué)生姓名： XXX 指導(dǎo)教師： XXX 摘 要 粒子跟蹤測(cè)速 (PTV)是一種全新無(wú)擾、瞬態(tài)、全場(chǎng)速度測(cè)量的方法，直接跟蹤流場(chǎng)中的示蹤粒子的運(yùn)動(dòng)，它的原理很簡(jiǎn)單，就是在流場(chǎng)中撒入示蹤粒子，假設(shè)示蹤粒子的運(yùn)動(dòng)準(zhǔn)確代表了其所在流場(chǎng)內(nèi)相應(yīng)位置流體的運(yùn)動(dòng)。首先使用脈沖片光源照射流場(chǎng)中的一個(gè)測(cè)試平面，利用這些粒子對(duì)光的散射作用，使用成像的方法記錄下流場(chǎng)中粒子的位置，然后對(duì)連續(xù)兩幀或者多幀圖像進(jìn)行處理分析，得出各點(diǎn)粒子的位移，最后根據(jù)粒子位移和曝光的時(shí)間間隔，便可以 計(jì)算出流場(chǎng)中各點(diǎn)的速度矢量，進(jìn)而可以得到其他的參數(shù)。 PTV圖像的處理過(guò)程主要包括粒子識(shí)別和粒子配對(duì)過(guò)程，在 PTV 技術(shù)研究中，粒子識(shí)別過(guò)程一般采用統(tǒng)一灰度閾值的方法來(lái)確認(rèn)，粒子配對(duì)則有許多不同的匹配方法。本文研究?jī)?nèi)容的重點(diǎn)是粒子配對(duì)過(guò)程，通過(guò)對(duì)幾種 PTV 匹配算法的介紹并且比較它們的優(yōu)缺點(diǎn)，選出其中一種匹配算法進(jìn)行改進(jìn)并通過(guò)編程實(shí)現(xiàn)，然后分別以模擬流場(chǎng)和實(shí)際流場(chǎng)對(duì)算法進(jìn)行驗(yàn)證，用算法獲得的流場(chǎng)速度分布與實(shí)際流場(chǎng)對(duì)比來(lái)評(píng)估該算法的優(yōu)劣和適用性。 關(guān)鍵詞 ： PTV；匹配算法；編程實(shí)現(xiàn) II Title: the Algorithm Design of PTV and Programming Realization name: XXX Supervisor: XXX ABSTRACT PTV is a brand new , instant state way without interference to measure the speed of all the field, directly tracing the movement of seeding particles in a field。 Its theory is very simple: dropping seeding particles in a field, let’s suppose the movement of seeding particles significantly represents the movement of the fluid’s , we make the pulse piece light source to ray a testing plane in the field,utilizing the scattering effect of the particles to light, making use of the imaging method to record the location of the particles in the flow field, then analyzing two or more images which are in series, the result is the displacement of every particle, in the end, in accordance with the displacement of a particle and the time interval of exposure ,we can caculate the speed vector of every particle in the flow field, and so do the other parameters. The process of PTV image mainly includes the process of particle identification and particle matching, from the PTV technical study, the process of particle identification usually utilize the same gray threshold to confirm, however, the process of particle matching have diverse range of matching measures. The essay mainly research the process of particle matching, by introducing some PTV matching measures, paring their relative merits, and improving one of them by programming, then validating by simulation field and reality field to the algorithm respectively, and evaluating the quality and applicability of the algorithm by matching the flow field velocity distribution which is obtained by the algorithm and reality field KEY WORDS: Ptv。Matching algorithm。Programming realiza目 錄 III 目 錄 摘 要 ............................................................................................................................................. I ABSTRACT…………………………………………………………………………………… ...II 1 緒論 ............................................................................................................................................ 1 研究背景 ............................................................................................................................. 1 PTV 原理與發(fā)展歷程 ......................................................................................................... 1 本文研究?jī)?nèi)容 ..................................................................................................................... 2 2 常見(jiàn)的 PTV 匹配算法原理 ...................................................................................................... 4 最近鄰法 ............................................................................................................................. 4 四幀粒子圖像跟蹤算法 ..................................................................................................... 4 PCSS 算法 ............................................................................................................................ 6 匹 配幾率法 ......................................................................................................................... 7 3 PTV 匹配算法及其驗(yàn)證 .......................................................................................................... 11 匹配算法評(píng)價(jià)方法 ........................................................................................................... 11 匹配算法原理對(duì)比分析 ................................................................................................... 11 算法改進(jìn)、實(shí)現(xiàn)與驗(yàn)證及其分析 ................................................................................... 12 算法改進(jìn)與實(shí)現(xiàn) ........................................................................................................ 12 模擬流場(chǎng)對(duì)算法的驗(yàn)證 ............................................................................................ 14 4 PTV 算法對(duì)實(shí)際圖像的處理及軟件界面設(shè)計(jì) ...................................................................... 32 算法對(duì)實(shí)際圖像的處理 ................................................................................................... 32 軟件界面設(shè)計(jì) ................................................................................................................... 33 5 結(jié)論與展望 .............................................................................................................................. 36 本文結(jié)論 ........................................................................................................................... 36 對(duì) PTV 算法的展望 ......................................................................................................... 38 參考文獻(xiàn) ...................................................................................................................................... 39 致 謝 .......................................................................................................... 錯(cuò)誤 !未定義書簽。 1 緒 論 1 1 緒論 研究背景 自阿基米德建立液體平衡理論以來(lái)，流體力學(xué)已有了兩千多年的歷史。流體力學(xué)的發(fā)展史從某種程度上可以說(shuō)是一部流體測(cè)量?jī)x器的發(fā)展史。因?yàn)榱黧w的運(yùn)動(dòng)非常復(fù)雜而且多變，所以它的運(yùn)動(dòng)規(guī)律一直是人類研究的重點(diǎn)，而將流體力學(xué)的研究 成果用到生產(chǎn)生活中更是人類最終的目標(biāo)。如今，經(jīng)過(guò)幾百年的努力，人們?cè)诹黧w力學(xué)的研究中已經(jīng)取得了非常大的成就，比如在流體測(cè)速技術(shù)方面的發(fā)展更是顯而易見(jiàn)，這對(duì)于發(fā)現(xiàn)流體的運(yùn)動(dòng)規(guī)律并進(jìn)而揭示流動(dòng)的內(nèi)在本質(zhì)具有決定性作用。但是目前的流體力學(xué)成就大多數(shù)只是對(duì)層流運(yùn)動(dòng)規(guī)律的研究，而對(duì)紊流本質(zhì)運(yùn)動(dòng)規(guī)律還依然有很長(zhǎng)的一段路要走，所以對(duì)紊流運(yùn)動(dòng)規(guī)律的研究是流體力學(xué)工作的重點(diǎn)。目前，對(duì)于紊流的研究，尤其是對(duì)紊流相干結(jié)構(gòu)的研究，所遇到的最大問(wèn)題之一就是對(duì)紊流瞬時(shí)流場(chǎng)的測(cè)量問(wèn)題。因?yàn)槿狈ψ銐蚩尚诺臏y(cè)量數(shù)據(jù)和資料，本來(lái)就極為復(fù)雜的紊 流研究就變得更加困難。 20 世紀(jì)以來(lái)，隨著流體力學(xué)的不斷發(fā)展，針對(duì)紊流瞬