摘要

本實驗是探討以不同衝擊位置，衝擊在加熱的粗糙面上，觀察其熱傳現象。主要目的在評估以不同的衝擊位置對於旋轉管道內部之熱傳影響，實驗控制參數有：兩種不同衝擊位置(衝擊在阻塊上以及兩阻塊之間)，雷諾數為5000~9000，轉數為0~600rpm，旋轉數Ro為0~0.0032，壁邊條件為均勻熱通量，阻塊幾何形狀為矩形及半圓形。實驗結果顯示，衝擊在阻塊上具有較佳的熱傳效果，在不同幾何形狀阻塊的熱傳影響方面，矩形阻塊的衝擊冷卻效果較佳。旋轉造成離心力以及柯氏力，使得噴流發生偏折，降低熱傳效果大約20%。

Abstract

The experiments was studied on a rotating ribbed square duct from two different impingement position of air jets (termed as Type A and B) and at rotational speeds of 0,300 and 600 rpm。The jet impinged on two different geometric types of rib (square and semi-circular ribs). The study covered jet Reynolds number 5000 to 9000 and the jet rotation number was varied from 0 to 0.0053. Results are presented and focused on the effect of two of circular jet arrangements and different geometric of ribs. Significant heat transfer enhancement was found for Type A configuration and square ribs within the ranges of operating parameters considered in the study. However, rotation induced Coriolis and centrifuged forces decreased the Nusselt number values (up to 20%) which is quitely conincided with those of previous studies.

目 錄
頁 次
目錄……………………………………………………………………………… i
圖目錄………………………………………………………………………………… iv
表目錄………………………………………………………….……vi
符號說明…………………………………………………………………………vii
論文摘要（中文）……………………………………………………………….x
論文摘要（英文）……………………………………………………………… xi

第一章 緒論…………………………………………………………… 1
1-1 前言…………………………………………………………… 1
1-2 背景與目的…………………………………………………… 1
1-3 文獻回顧……………………………………………………… 2
1-4 研究範圍……………………………………………………… 7

第二章 實驗設備………………………………………………………… 11
2-1 旋轉及測試系統……………………………………………… 11
2-2 測試區裝置…………………………………………………… 12
2-3 高壓空氣供應及壓力、流量控制系統…………………… 12
2-4 加熱及控制系統……………………………………………… 12
2-5 溫度量測系統………………………………………………… 13

第三章 實驗量測方法及步驟………………………………………… 16
3-1 實驗量測方法………………………………………………… 16
3-1-1 流量量測………………………………………………… 16
3-1-2 溫度量測………………………………………………… 27
3-2 實驗步驟……………………………………………………… 17

第四章 實驗數據處理………………………………………………… 20
4-1 熱傳係數……………………………………………………… 20
4-2 平均鈕塞數.……….………………………………………… 21

第五章 誤差分析……………………………………………..…….…. 22

第六章 結果與討論………………………………………..…………... 25
6-1 熱傳係數………………………………………………………. 26
6-1-1 局部熱傳係數………………………………..…………… 26
6-1-2 旋轉對局部熱傳係數之影響……………………………27
6-1-3 不同衝擊位置對局部熱傳係數之影響局部熱傳係數…27
6-1-4 不同幾何形狀粗糙面對局部熱傳係數之影響…………28
6-1-5 結合旋轉、粗糙面幾何形狀、不同衝擊位置對局部熱傳
係數之影響…………………………...…………………28
6-2 平均熱傳係數………………………………………….…….29

第七章 結論與建議………………………………………………………47
參考文獻……………………………………………………………………… 49
附錄：誤差分析………………………………………………………………..54


圖 目 錄

頁次
圖1.1 流場示意圖…………………………………………………… 8
圖2.1 實驗設備配置圖………………………………………………….14
圖2.2 測試區幾何尺寸圖………………………………………………15
圖3.1 實驗步驟流程圖…………………………………………………19
圖6.1 靜止方形阻塊之粗糙管，衝擊在兩阻塊之間，紐塞數(Nusselt number)與x/dj之關係…… …………………………………..30
圖6.2 靜止方形阻塊之粗糙管，衝擊在阻塊上，紐塞數(Nusselt umber)與x/dj之關係…… …………………………………..………..31
圖6.3 靜止半圓形阻塊之粗糙管，衝擊在兩阻塊之間，紐塞數Nusselt number)與x/dj之關係…… …………………………………..32
圖6.4 靜止半圓形阻塊之粗糙管，衝擊在阻塊上，紐塞數(Nusselt number)與x/dj之關係…… …………………………………..33
圖 6.5 旋轉方形粗糙管，衝擊在兩阻塊之間，紐塞數(Nusselt number)與x/dj的關係………………………………………………….34
圖6.6 旋轉方形粗糙管，衝擊在阻塊上，紐塞數(Nusselt number)與x/dj的關係……………………………………………………..35
圖 6.7 旋轉半圓形粗糙管，衝擊在兩阻塊之間，紐塞數(Nusselt number)與x/dj的關係…………………………………………36
圖6.8 旋轉半圓形粗糙管，衝擊在阻塊上，紐塞數(Nusselt number)與x/dj的關係………………………………………………….37
圖 6.9 旋轉方形粗糙管，Type A以及Type B，紐塞數(Nusselt number)與x/dj之關係………………………………………………….38
圖6.10 旋轉半圓形粗糙管，Type A以及Type B，紐塞數(Nusselt umber)與x/dj之關係……………………………………….………….39
圖6.11 旋轉粗糙，衝擊在兩阻塊之間，不同幾何形狀阻塊，紐塞數(Nusselt number)與x/dj之關係………………………………..40
圖6.12 旋轉粗糙，衝擊在阻塊上，不同幾何形狀阻塊，紐塞數(Nusselt number)與x/dj之關係…………………………………………41
圖6.13 受旋轉，粗糙面幾何形狀及不同衝擊位置等效應，紐塞數(Nusselt number)比值與x/dj之關係………………………….42
圖6.14 矩形阻塊，向心通道(Inward radial flow)/離心通道(Outward radial flow)平均紐塞數與雷諾數之關係……………………..43
圖6.15 半圓形阻塊，向心通道(Inward radial flow)/離心通道(Outward radial flow)平均紐塞數與雷諾數之關係……….…………….44
圖6.16 矩形阻塊，向心通道(Inward radial flow)/離心通道(Outward radial flow)平均紐塞數與旋轉數之關係……………………..45
圖6.17 半圓形阻塊，向心通道(Inward radial flow)/離心通道(Outward radial flow)平均紐塞數與雷諾數之關係……………………..46

表 目 錄

頁次
表1.1 有關旋轉通道衝擊冷卻實驗相關參數比較…………….……..9
表1.2 阻塊幾何尺寸與相關參數…………………………………….10
表5.1 參數及變數誤差值……………………………………………..24



符 號 說 明

A ：加熱表面的面積
Af ：噴嘴總面積與加熱表面的面積之比值（open area ratio）,
nπ /4A
dj ：圓孔噴嘴直徑
Dh ：水力直徑，2 W H/（W+H）
e ：阻塊的高度
h ：熱對流係數
kf ：空氣的熱傳導係數
：測試區長度
Νu ：局部鈕塞數
Νur ：旋轉管道之鈕塞數
Νus ：靜止管道之鈕塞數
P ：絕對壓力
P ：阻塊的節距
Qt ：輸入測試區之總加熱量
q ：單位面積平均熱通量，Qcv／Α
R ： 旋轉半徑（=150mm）
Rej ：噴流雷諾數，Vj dj ／ν
ReΩ ：旋轉雷諾數，Ωdj 2／ν
Ro ：旋轉數，ReΩ/ Rej=Ωdj /Vj
Tb ：空氣局部平均溫度（air buck temperature）
Tj ：噴嘴出口溫度
Tw ：壁溫
Vj ：噴嘴出口速度
x ：測向沿出口方向的距離
x/ dj ：無因次沿出口方向的距離與噴嘴直徑之比
Zn ：加熱壁邊與噴嘴的距離

希臘字母
Δ ：差距
ν ：空氣動黏度係數
：密度(Density)
Ω ：旋轉速度
上標
__ ：平均值

下標
a ：空氣
j ：噴流
n ：噴嘴數目
w ：壁邊
Ω ：旋轉
s ：矩形阻塊
s.c ：半圓形阻塊
A ：衝擊在阻塊上
B ：衝擊在兩阻塊之間

參 考 文 獻
1. Akella, K. V., and Han, J. C., 1999, “Impingement Cooling in Rotating Two-Pass Rectangular Channels with ribbed walls,” Journal of Thermophysics and heat transfer, Vol. 13, pp. 364-371.
2. Akella K. V., and Han J. C., 1998, “Impingement Coling in Rotating Two-Pass Rectangular Channels,” AIAA Journal of Thermophysics and Heat Transfer, Vol. 12, PP. 79-85.
3. Becko, Y., 1976, “Impingement Cooling-a Review,” Von Karman Institute for Fluid Dynamics, Lecture Series 83, Turbine Blade Cooling.
4. Behbahani, A. I., Disimile, P. J., and Aydore, S., 1989, “Flow Visualization in An Impinging Circular Air Jet,” National Heat Transfer Conference HTD-Vol. 112, Heat Transfer Measurements, Analysis, and Flow Visualization.
5. Baydar, E., 1999, “Confined impinging air jet at low Reynolds numbers,” Experimental Thermal and Fluid Science, Vol. 19, pp. 27-33.
6. Brignoni, L. A., and Garimella, S. V., 2000, “Effects of Nozzle-Inlet Chamfering on Pressure Drop and Heat Transfer in Confined Air Jet Impingement,” International Journal of Heat and Mass Transfer, Vol. 43, pp. 1133-1139.
7. Chou, Y. J., and Hung, Y. H., 1994, “Impingement Cooling of an Isothermally Heated Surface With a Confined Slot Jet,” Journal of Heat Transfer, Vol.116, pp. 479-482.
8. Colucci, D. W., and Viskanta R., 1996, “Effect of Nozzle Geometry on Local Convective Heat Transfer to a Confined Impinging Air Jet,” Experimental Thermal and Fluid Science, Vol. 13, pp.71-80.
9. Chandra, P. R., Fontenot, M. L., and Han, J. C., 1998, “Effect of Rib Profiles on Turbulent Channel Flow Heat Transfer,” Journal of Thermophysics and Heat Transfer, Vol. 12, pp. 116-118.
10. Donaldson, C. D., and Snedeker, R. S., 1971a, “A Study of Free Jet Impingement, Part 1. Mean Properties of Free and Impinging Jets,” Journal of Fluid Mechanics, Vol. 45, part 2, pp.281-319.
11. Donaldson, C. D., and Snedeker, R. S., 1971b, “A Study of Free Jet Impingement, Part 2. Free Jet Turbulent Structure and Impingement Heat Transfer,” Journal of Fluid Mechanics, Vol. 45, Part 3, pp.477-512.
12. Fitzgerald, J. A., and Garimella, S. V., 1997, “Flow Field Effects on Heat Transfer in Confined Jet Impingement,” Journal of Heat Transfer, Vol. 119, pp. 630-632.
13. Gardon, R., and Cobonpue, J., 1963, “Heat Transfer Between a Flat Plate and Jets of Air Impinging on It,” in: International Developments in Heat Transfer, Proceedings of the 2nd International Heat Transfer Conference, ASME, pp. 454-460.
14. Gardon, R., and Akfirat, J. C., 1965 “The Role of Turbulence in Determining the Heat Transfer Characteristics of Impinging Jets,” International Journal of Heat Mass Transfer, Vol. 8, pp. 1261-1272.
15. Gardon, R., and Akfirat, J. C., 1966, “Heat Transfer Characteristics of Impinging Two-Dimensional Air Jets,” Journal of Heat Transfer, Vol.88, pp. 101-108.
16. Gau, C., and Chung, C. M., 1991, “Surface Curvature Effect on Slot-Air-Jet Impingement Cooling Flow and Heat Transfer Process,” Journal of Heat Transfer, Vol. 113, pp. 858-864.
17. Gau, C., and Lee, C. C., 1992, “Impingement Cooling Flow Structure and Heat Transfer along Rib-Roughened Walls,” International Journal of Heat Mass Transfer, Vol. 35, pp. 3009-3020.
18. Gau, C., and Lee, I. C., 2000, “Flow and Impingement Cooling Heat Transfer Along Triangular Rib-Roughened Walls,” International Journal of Heat and Mass Transfer, Vol. 43, pp. 4405-4418.
19. Goldstein, R. J., and Behbahani, A. I., 1982, “Impingement of a Circular Jet With and Without Cross Flow,” International Journal of Heat and Mass Transfer, Vol. 25, pp. 1377-1382.
20. Goldstein, R. J., Behbahani, A. I., and Heppelmann, K. K., 1986, “Streamwise Distribution of the Recovery Factor and the Local Heat Transfer Coefficient to an Impinging Circular Air Jet,” International Journal of Heat and Mass Transfer, Vol. 29, pp. 1227-1235.
21. Goldstein, R. J., and Franchett, M. E., 1988, “Heat Transfer From a Flat Surface to an Oblique Impinging Jet,” Journal of Heat Transfer, Vol. 110, pp. 84-90.
22. Goldstein, R. J., Sobolik, K. A., and Seol, W. S., 1990, “Effect of Entrainment on the Heat Transfer to a Heated Circular Air Jet Impinging on a Flat Surface,” Journal of Heat Transfer, Vol. 112, pp. 608-611.
23. Garimella, S. V., and Rice, R. A., 1995, “Confined and Submerged Liquid Jet Impingement Heat Transfer,” Journal of Heat Transfer, Vol. 117, pp. 871-877.
24. Hong, Y. J., and Hsieh, S. S., 1993, “Heat Transfer and Friction Factor Measurements in Ducts With Staggered and In-Line Ribs,” Journal of Heat Transfer, Vol. 115, pp. 58-65.
25. Hsieh, S. S., and Hong, Y. J., 1995, “Heat transfer Coefficients in an Orthogonally Rotating Duct With Turbulators,” Journal of Heat Transfer, Vol. 117, pp. 69-78.
26. Hsieh, S. S., Huang J. T., and Liu, C. F., 1999, “Local Heat Transfer in a Rotating Square Channel With Jet Impingement,” Journal of Heat Transfer, Vol. 121, pp. 811-818.
27. Ichimiya, K., and Hosaka, N., 1992, “Experimental Study of Heat Transfer Characteristics due to Confined Impinging Two-Dimensional Jets,” Experimental Thermal and Fluid Science, Vol. 5, pp. 803-807.
28. Jambunathan, K., Lai, E., Moss, M. A., and Button, B. L., 1992, “A Review of Heat Transfer data for Single Circular Jet Impingement,” International Journal of Heat and Fluid Flow, Vol. 13, pp. 106-115.
29. Lytle, D., and Webb, B. W., 1994, “Air Jet Impingement Heat Transfer at Low Nozzle-Plate Spacings,” International Journal of Heat and Mass Transfer, Vol. 37, pp. 1687-1697.
30. Lin, Z. H., Chou, Y. J., and Hung, Y. H., 1997, “Heat Transfer Behaviors of a Confined Slot Jet Impingement,” International Journal of Heat and Mass Transfer, Vol. 40, pp. 1095-1107.
31. Mattern, C., and Hennecke, D. K., 1996, “The Influence of Rotation on Impingement Cooling,” International Gas Turbine and Aeroengine Congress & Exhibition Birmingham, UK-June 10-13.
32. Martin, H., 1997, “Heat and Mass Transfer Between Impinging Gas Jet and Solid Surface,” Advances in Heat Transfer, Vol. 13, pp. 1-60.
33. Pamadi, B. N., and Belov, I. A., 1980, “A Note on the Heat Transfer Characteristics of Circular Impinging Jet,” International Journal of Heat and Mass Transfer, Vol. 23, pp. 783-787.
34. Popiel, C. O., and Trass, O., 1991, “Visualization of a Free and Impinging Round Jet,” Experimental Thermal and Fluid Science, Vol. 4, pp. 253-264.
35. Parsons, J. A., Han, J. C., and Lee, C. P., 1998, “Rotation Effect on Jet Impingement Heat Transfer in Smooth Rectangular Channels With Four Heated Walls and Radially Outward Crossflow,” Journal of Turbomachinery, Vol. 120, pp. 79-85.
36. Sparrow, E. M., and Wong, T. C., 1975, “Impingement Transfer Coefficients Due to Initially Laminar Slot Jets,” International Journal of Heat and Mass Transfer, Vol. 18, pp. 597-605.
37. Shadlesky, P. S., 1982, “Stagnation Point Heat Transfer for Jet Impingement to a Plane Surface,” AIAA Journal, Vol. 21, pp. 1214-1215.
38. Stevens, J., and Webb, B. W., 1991, “Local Heat Transfer Coefficients Under an Axisymmetric, Single-Phase Liquid Jet,” Journal of Heat Transfer, Vol. 113, pp. 71-78.
39. San, J. Y., Huang, C. H., and Shu, M. H., 1997, “Impingement Cooling of a Congined Circular Air Jet,” International Journal of Heat and Mass Transfer, Vol.40, pp. 1355-1364.
40. Tabakoff, W., and Clevenger, W., 1972, “Gas Turbine Blade Heat Transfer Augmentation by Impingement of Air Jets Having Various Configurations,” Journal of Engineering for Power, Vol. 94, pp. 51-60.
41. Vader. D. T., Incropera, F. P., and Viskanta, R., 1991, “Local Convective Heat Transfer From a Heated Surface to an Impinging, Planar Jet of Water,” International Journal of Heat and Mass Transfer, Vol. 34, pp. 611-623.
42. Womac, D. J., Ramadhyani, S., and Incropera, F. P., 1993, “Correlating Equations for Impingement Cooling of Small Heat Sources With Single Circular Liquid Jets,” Journal of Heat Transfer, Vol. 115, pp. 106-115.
43. Zumbrunnen, D. A., Incropera, F. P., and Viskanta, R., 1989, “Convective Heat Transfer Distributions on a Plate Cooled by Planar Water Jets,” Journal of Heat Transfer, Vol. 111, pp. 889-896.