簡易檢索 / 詳目顯示

研究生: 黃文竣
Huang, Wen-Jun
論文名稱: 理想氣體擬似穩態馬赫反射流場三震波理論計算與實驗分析
A Theoretical and Experimental Analysis of Pseudo-Steady Mach Reflections in Perfect Gases
指導教授: 劉中堅
Liu, Jong-Jian
學位類別: 碩士
Master
系所名稱: 工學院 - 工程科學系
Department of Engineering Science
論文出版年: 2006
畢業學年度: 94
語文別: 中文
論文頁數: 204
中文關鍵詞: 三震波馬赫反射
外文關鍵詞: three shock, Mach reflection
相關次數: 點閱:64下載:1
分享至:
查詢本校圖書館目錄 查詢臺灣博碩士論文知識加值系統 勘誤回報
  • 本文首先討論Olim & Dewey (1992)與Sandeman (2000)提出弱擬似穩態馬赫反射流場三震波理論的修正理論,吾人於許多Olim & Dewey (1992)實驗條件下,應用其修正理論計算得到Sin(phi2)值(phi2 意指反射震波之波角)都是大於1,所以phi2值不存在,亦即其論文中許多之Wir 與qw+X 曲線圖中數據是錯誤的;Sandeman (2000)提出圖解法求取三震波點路徑角(X),吾人分別應用Olim & Dewey (1992)實驗數據X角及Liu (1996)擬似穩態馬赫反射流場入射震波下游流場聲波公式計算X 角,三者比較發現當楔型斜平面角較小時,Sandeman方法得到X角比上述聲波理論得到之X角更遠離實驗量測之 角,當楔型斜平面角較大時,Sandeman方法得到 角與實驗量測X角差異很大。之後應用牛頓數值方法求解局部及整體擬似穩態馬赫反射流場三震波理論十四個變數之非線性十四聯立方程式,文中說明牛頓數值方法如何解此聯立方程組,並對各種不同類型之局部擬似穩態馬赫反射震波極圖解(全部共六種類型)有系統地每2度變化phi2及phi3猜值(包含全部後向反射震波解(自phi2後向馬赫波角至phi2=90度)與全部前向反射震波解(自phi2=90度 至phi2前向馬赫波角)),配合擬似穩態馬赫反射十階多項式理論,分析所得到之牛頓數值解,初步成功地得到 phi2及phi3猜值於馬赫反射(pressure-deflection)震波極圖解平面上的切線法,來描述 及 猜值對牛頓數值方法求解局部擬似穩態馬赫反射三震波理論解之影響。此切線法之結論為:於phi2與phi3猜值位置描繪出此二切線,其相交點位置將會鄰近於上述十階多項式理論所得到震波極圖解上交點解,而後將該phi2及phi3猜值代入牛頓數值方法計算所得到之結果,半數以上亦為相當接近上述該鄰近交點之近似解(須排除不適當phi2及phi3猜值所得到無解之狀況),一般而言,若phi2及phi3猜值鄰近phi2及phi3理論解,則牛頓數值方法都能準確地得到該擬似穩態馬赫反射流場理論震波解。吾人之後改變分離流邊界收斂條件,觀察其對局部擬似穩態馬赫反射流場多重解之影響(共七種類型,三十二個實驗例子)。我們發現入射震波極與反射震波極非常接近且增大分離流收斂條件得到之解,多數是鄰近所選擇 及 猜值而偏離十階多項式理論所得到之解,也就是所選 猜值於何處則所得到之 值答案亦將出現在所猜之 猜值附近。實驗方面,應用陰影法及紋影法兩種型態之拍攝方法,進行流場可視化實驗,同時依據可視化流場之對比度公式可以了解影響甚鉅之刀片遮光高度,隨後作一系列之變化遮光比例實驗,觀察遮光條件是否會影響對比度。吾人發現當遮光比較低時,擬似穩態馬赫反射流場之反射波於照片中較不清楚,且反射波為白色,當遮光比較高時,照片中之反射波較為清楚,且反射波為黑色。最後將所作之 及 系列遮光比之實驗照片繪其馬赫反射流場入射震波下游流場之聲波圖與量測此流場波型結構,並將實驗結果分別應用局部三震波理論、整體三震波理論及上述之聲波理論分析與討論實驗結果。

    Works of Olim & Dewey (1992) and Sandeman (2000), which proposing revised three-shock theories of weak pseudo-steady Mach reflections (MR), are first discussed. Using Olim & Dewey (1992) experiments and their revised theory for calculating reflected shock wave angles (phi2), we obtain, in many cases, values of larger than 1! Therefore, many datum in their graphs (Olim & Dewey (1992)) of Wir vs. qw+X are incorrect; Sandeman (2000) proposed a graphical method for calculating the triple-point trajectory angle (X). We again use experiments along with Liu (1996) for calculating X angles. It is found that, when reflecting angles of pseudo-steady MR are small, predictions obtained from Sandeman (2000) deviate more from Olim & Dewey’s (1992) experiments than those obtained from Liu’s (1996) sound structure theory downstream of pseudo-steady MR. On the other hand , when reflecting angles of pseudo-steady MR are not small, predictions obtained from Sandeman (2000) compare badly with the experiments. The focus of this thesis is to study numerical solutions of 14 nonlinear algebraic conservation equations, describe 14 flow valuables downstream of incident, reflected, and Mach shocks of perfect-gas pseudo-steady MR using the Newton method. Rationality about algorithms used in successfully computing correct solutions of pseudo-steady MR is explained. In general, with phi2 and phi3 values properly chosen, numerical solutions of pseudo-steady MR using the Newton method agree well with corresponding theoretical solutions obtained from the tenth degree polynomial equation of three-shock confluences Henderson (1964) and Liu (2003). Effects of varying guessed phi2 (reflected shock wave angle) and phi3 (Mach stem wave angle) on computed Newton numerical solutions of local and global three-shock theoretical solutions of pseudo-steady MR are systematically analyzed, with respect to six different types of (pressure-deflection) theoretical solutions of them. The range of guessed phi2 of these Newton numerical works (for each of these six different types) start from backward (forward)-facing Mach angle of phi2 to phi2=90 degree for all reflected backward (forward)-facing reflected shock solutions. They are then carried out for every two degrees of guessed phi2 for a given guessed phi3. It is found that a useful graphical “tangent” method on the (pressure-deflection) plane can successfully describe the effects of varying guessed phi2 and phi3 on these computed Newton numerical solutions. The results are that intersection points between phi2 and phi3 tangents are close to computed Newton numerical solutions of pseudo-steady MR using these guessed values of phi2 and phi3 for more than half of these obtained solutions. The effect of varying converging conditions of slipstream compatibility (pressure and deflection) conditions is subsequently studied for seven different theoretical pseudo-steady MR solution patterns using 32 (existing) experimental cases. It is found that, when portions of computed incident and reflected shock polars are indistinguishable, pseudo-steady MR phi2 (for fixed phi3 conditions) solutions obtained from the Newton’s method are almost always close to guessed phi2 values as values of converging conditions of slipstream compatibility requirements become large. Experimentally, shadowgraph and schlieren methods are applied to obtain flow visualization photographs of pseudo-steady MR experiments. A series of light-shielding tests are performed to examine this effect of knife-edge shielding on image contrast of schlieren photographs. It is found that obtained images (lighter) of reflected waves are more sensitive to lowering knife-edge shielding percentage than those images (darker) of incident and Mach shock waves. Finally, sound wave structures downstream of incident shock of these flow visualization photographs of Ms=1.36 ,qw=8 degree are drawn along with their comparisons with computed local and global three-shock theoretical pseudo-steady MR solutions.

    目錄 摘要 ……………………………………………………………………Ⅰ ABSTRACT ………………………………………………………………Ⅳ 誌謝 ……………………………………………………………………Ⅵ 目錄 ……………………………………………………………………Ⅶ 圖目錄 …………………………………………………………………XI 表目錄 ………………………………………………………………..XVI 符號說明 …………………………………………………………..XVIII 第一章 緒論 ……………………………………………………………1 第二章 擬似穩態馬赫反射參震波理論之回顧 ……………………..11 2-1 擬似穩態馬赫反射之傳統參震波理論 …………...................11 2-2 擬似穩態弱馬赫反射傳統參震波理論之修正 ………….......17 2-2-1 Olim 與Dewey (1992)修正弱擬似穩態馬赫反射理論之說明 18 2-2-2 Olim 與Dewey (1992)修正理論之討論 ………………………21 2-2-3 Sandeman修正擬似穩態馬赫反射理論之說明 ………………..28 2-3 穩態馬赫反射流場之十階多項式理論 ……………………...32 2-4 十階多項式理論應用於擬似穩態馬赫反射流場 …………...36 2-5 馬赫反射流場參震波理論之壓力與轉折角(pressure-deflection)震波極圖解法 37 2-5-1 穩態馬赫反射流場參震波理論之(pressure-deflection)震波極圖解法 37 2-5-2 擬似穩態馬赫反射流場參震波理論之(pressure-deflection)震波極圖解法 ….......................................................................40 第三章 馬赫反射流場參震波理論之非線性十四個聯立方程式解之計算(牛頓法)結果分析與討論 ………………………………..41 3-1 穩態馬赫反射流場參震波理論之非線性十四個聯立方程式解之計算方法(牛頓法)41 3-2 擬似穩態馬赫反射流場參震波理論之非線性十四個聯立方程式解之計算方法(牛頓法) …………………………………..53 3-3 局部與整體擬似穩態馬赫反射流場參震波理論之牛頓數值方法與穩態馬赫反射十階多項式理論之計算與實驗結果三者之比較討論…………………56 3-3-1 擬似穩態馬赫反射流場三震波理論之牛頓數值方法於固定分離 流邊界收斂條件(E=1x10^-5)下 …………………………...57 3-4 反射震波之波角phi2猜值與馬赫莖之波角phi3猜值對局部擬似穩態馬赫反射流場參震波理論多重解之影響 ………………..69 3-4-1 探討phi2及phi3猜值對擬似穩態馬赫反射流場後向有一交點解(m=1)尋找數值解之影響 ……………………………………………...70 3-4-2探討phi2及phi3猜值對擬似穩態馬赫反射流場前向有一交點解(m=1)尋找數值解之影響 ……………………………………………...77 3-4-3 探討phi2及phi3猜值對擬似穩態馬赫反射流場alpha1交點解位於D2退化解之下(m=0)尋找數值解之影響 ……………………………...84 3-4-4 探討phi2及phi3猜值對擬似穩態馬赫反射流場alpha1交點解位於D1退化解之下(m=0)尋找數值解之影響 ……………………………...90 3-4-5 探討phi2及phi3猜值對擬似穩態逆馬赫反射(Inverse Mach Reflection)流場且m=2尋找數值解之影響 …………………96 3-4-6 探討phi2及phi3猜值對擬似穩態馬赫反射流場前向三個交點解(m=3)尋找數值解之影響 …………………………………………….104 3-5 分離流邊界收斂條件對局部擬似穩態馬赫反射流場參震波理論多重解之影響 ……………………………………………111 3-5-1 擬似穩態馬赫反射流場後向有一個交點解(m=1)之類型 …..113 3-5-2 擬似穩態馬赫反射流場前向有一個交點解(m=1)之類型 …..121 3-5-3 擬似穩態馬赫反射流場alpha1交點解位於D2退化解之下(m=0)之類型 ………130 3-5-4 擬似穩態馬赫反射流場alpha1交點解位於D1退化解之下(m=0)之類型 …………………………………………………………….....138 3-5-5 擬似穩態馬赫反射流場alpha1及beta1交點解位於D2退化解之上(m=2)之類型 ………………………………………………………..........146 3-5-6擬似穩態逆馬赫反射流場alpha1、beta1及beta2交點解位於D2退化解之上 (m=3)之類型 …………………………………………………152 3-5-7 擬似穩態馬赫反射流場前向有三個交點解(m=3)之類型 …..158 第四章 矩形截面震波管實驗原理與步驟 ………………………....164 4-1 震波管之簡介 ……………………………………………….164 4-2 光學視流方法之說明 ……………………………………….166 4-2-1 視流方法之討論 ……………………………………..................166 4-2-2 紋影法之基本原理 ……………………………………………..170 4-3 擬似穩態馬赫反射流場之實驗方法與步驟 ……………….178 4-3-1 擬似穩態馬赫反射流場之實驗設備 …………………………..178 4-3-2 擬似穩態馬赫反射流場實驗之操作程序 ……………………..178 4-3-3 擬似穩態馬赫反射流場流場實驗觀測之步驟 ………………..182 4-3-4 擬似穩態馬赫反射流場流場之實驗方法 ……………………..187 4-4 擬似穩態馬赫反射流場實驗之觀測結果與討論 …………190 第五章 結論 …………………………………………………………197 參考文獻 ……………………………………………………………..203 簡歷

    參考文獻
    Deschambault, R.L., “Nonstationary oblique-shock-wave reflections in air,” UTIAS Rep. 270, (1984).
    Griffith, W.C., “Shock waves,” J. Fluid Mech., vol. 106, pp. 81-101, (1981).
    Ben-Dor, G., and Takayama, K., “The phenomena of shock wave reflection-a view of unsolved problems and future research needs,”shock wave, vol. 2, pp. 211-223, (1992).
    Goldstein, R.J., “Fluid mechanics measurements,”Second edition,Taylor & Francis publishers,University of Minnesota, pp. 451-474, (1996).
    Henderson, L. F., “On the confluence of three shock waves in a perfect gas, ” Aero. Quart., 15, pp. 181-197, (1964).
    Henderson, L. F., “Regions and boundaries for diffracting shock wave systems,” Z. Angew, vol 67, pp. 1-14, (1987).
    Kawamura, R. & Saito, H., “Reflection of shock waves – 1. pseudo-stationary case,” J. Phys. Soc. Japan, vol. 11, pp. 584-592, (1956).
    Liu, J.J., “Sound wave structures downstream of pseudo-steady weak and strong mach reflections,” J. Fluid Mech., vol. 324, pp. 309-332, (1996).
    Liu, J.J., “A one-dimensional stream-tube interpretation of Liu’s revised three-shock theory for pseudo-steady Mach reflections,” The 23 rd International symposium on shock Wave, Fort Worth, Texas. USA, (2001).
    Liu, J.J., Shih, M.C., Yang, Y.Q., Tseng K.Y., “Preliminary regimes of multiplicity of three-shock theoretical solutions of steady Mach reflections in perfect triatomic gases,” The 20th Nat’l Conference on Mechanical Engineering, pp. 427-434, (2003).
    Liu, J.J., “Multiple three-shock theoretical solutions of steady Mach reflections in triatomic perfect-gases,” The 5th International Workshop on Shock/Vortex Interaction, (2003a).
    Liu, J.J., “A map of multiplicity of perfect-gas three-shock theoretical solutions of steady Mach reflections in diatomic gases,” The 5th International Workshop on Shock/Vortex Interaction, (2003b).
    Law, C.K. and Glass, I.I. “Diffraction of strong shock waves by a sharp compressive corner,”CASI,Trans,4, pp. 2-12, (1971).
    Mach, E., ”Uber einige mechanische Wirkungen des electrischen Funkens, ” Akademie der Wissenschaften Wien, vol. 77, No. II, pp. 819-838, (1878).
    Neumann, J. von, “On refraction, interaction and reflection of shock waves,” NAVORD Rep. 203-45, Navy Dept., Bureau of Ordinance, Washington, DC. (1945).
    Olim, M. & Dewey, J.M. “A revised three-shock solution for the Mach reflection of weak shocks(1.1<Mi<1.5),” Shock Waves Intl J. 2, pp. 167-176, (1992).
    Sandeman, R.J., “A simple physical theory of weak Mach reflection over plane surfaces,” Waves, vol. 10, pp. 103-112, (2000).
    Smith, L.G. “Photographic investigation of the reflection of plane shocks in air, ” OSRD Rep. 6721. Off. Sci. Res. Dev, Washington, DC, (1945).
    Settles, G. S., “Modern developments in flow visualization,” AIAA J.,vol. 24, No. 8, pp. 1313-1323, (1991).
    莊俊忠,「馬赫反射現象之理論探討」,國立成功大學工程科學系碩士論文,台南 (2002)。

    下載圖示 校內:立即公開
    校外:2006-09-04公開
    QR CODE