### 博碩士論文 87323090 完整後設資料紀錄

 DC 欄位 值 語言 DC.contributor 機械工程學系 zh_TW DC.creator 彭光榮 zh_TW DC.creator Guo-Long Peng en_US dc.date.accessioned 2000-7-5T07:39:07Z dc.date.available 2000-7-5T07:39:07Z dc.date.issued 2000 dc.identifier.uri http://ir.lib.ncu.edu.tw:88/thesis/view_etd.asp?URN=87323090 dc.contributor.department 機械工程學系 zh_TW DC.description 國立中央大學 zh_TW DC.description National Central University en_US dc.description.abstract 低紊流強度預混焰之傳播，我們主要是以離子探針定量量測甲烷-空氣(當量比f = 0.7~1.4)及丙烷-空氣(f = 0.7~1.5)預混燃氣於不同風扇轉頻(f = 3~9Hz)下預混焰的燃燒速度(ST)，並以高速攝影機觀測燃燒器測試區預混焰和紊流間之交相干涉。實驗結果：(1) 所量測的低紊流(u’’/SL < 1)燃燒速度可用ST/SL=1+1.82(u’’/SL)1.21之經驗來代表，SL為層流燃燒速度而u’’為能量平均紊流強度，此結果與雙攝影機法所得到的結果頗相符合，但是大於先前之理論預測值ST/SL = 1+(u’’/SL)2 (Clavin & Williams 1979)、ST/SL = 1+(u’’/SL)4/3 (Kerstein & Ashurst 1994)及ST/SL = 1.26+0.38(u’’/SL) (Cambray & Joulin 1993)；(2) 根據雷諾數的分析結果可以知道，低紊流燃燒速度是與雷諾數成正比的關係，且低紊流燃燒速度隨雷諾數增大而增加的幅度會隨當量比的改變而有所不同；(3) 在固定u’’/SL(< 1)時，有明顯的Lewis數(Le)效應，即ST/SL值在Le < 1高出ST/SL在Le > 1時之值甚多。(4) 紊流燃燒速度會隨著紊流強度的增加而增加，但是所增加的幅度會受到Le效應及不同雷諾數的影響而有所不同。 另外，高紊流強度預混焰的熄滅，我們主要是以雙攝影機法來作定性的觀測，並針對燃燒過後的殘餘燃氣濃度來進行定量的量測，以確定出預混焰發生整體熄滅的臨界值。此部份目前仍在繼續地進行中，本論文僅討論初步的結果。 zh_TW dc.description.abstract For low-intensity premixed turbulent combustion, we use a pair of specially-designed ion probe sensors, such that turbulent burning velocities of both methane-air and propane-air mixtures are quantitatively measured. Our results show: (1) The results of turbulent burning velocity measurements can be represented as an empirical relation of the form ST/SL=1+1.82(u’’/SL)1.21, where ST is the turbulent burning velocity, SL is the laminar flame speed, and u’’ is turbulent intensity. This result is very close to the previous result obtained by the two-camera method, but higher than that of theories by Clavin & Williams (1979), Kerstein & Ashurst (1994), and Cambray & Joulin (1993). (2) The turbulent burning velocity is proportion to the Reynolds number, but the increasing magnitude varies with the equivalence ratio. (3) At the same turbulent intensity condition, the turbulent burning velocity for Le < 1 is greater than that for Le > 1, where Le = a/D, a is thermal diffusivity and D is mass diffusivity. To determine the quenching mechanism for high-intensity premixed turbulent combustion, we use the high-speed camera to obtain the instantaneous images from the test section of the burner. The Thermal Conductivity Detector mount is used to measure the methane concentration. We present only some preliminary results about global quenching experiments, which are still conducting in our laboratory. en_US DC.subject 近似等向性紊流場 zh_TW DC.subject 預混紊流燃燒 zh_TW DC.subject 雷諾數 zh_TW DC.subject Lewis數 zh_TW DC.title 低紊流強度預混焰之傳播及高紊流強度預混焰之熄滅 zh_TW dc.language.iso zh-TW zh-TW DC.type 博碩士論文 zh_TW DC.type thesis en_US DC.publisher National Central University en_US