進階搜尋


   電子論文尚未授權公開,紙本請查館藏目錄
(※如查詢不到或館藏狀況顯示「閉架不公開」,表示該本論文不在書庫,無法取用。)
系統識別號 U0026-0108201716274800
論文名稱(中文) 風場數值模擬在離岸領域的應用
論文名稱(英文) Application of numerical simulation of wind field in offshore domain
校院名稱 成功大學
系所名稱(中) 航空太空工程學系
系所名稱(英) Department of Aeronautics & Astronautics
學年度 105
學期 2
出版年 106
研究生(中文) 阮趙日青
研究生(英文) Thanh Nhat Trieu Nguyen
學號 P46047132
學位類別 碩士
語文別 英文
論文頁數 88頁
口試委員 指導教授-苗君易
指導教授-林三益
口試委員-呂宗行
口試委員-蔡原祥
中文關鍵字 none 
英文關鍵字 Weather Research and Forecasting (WRF)  Large eddy simulation (LES)  Detached eddy simulation (DES)  Computational Fluid Dynamics (CFD) 
學科別分類
中文摘要 none
英文摘要 Wind resource assessment is the foundation of wind farm development. The wind farms depend on meteorological conditions, especially the magnitude of the wind speed. Thus, the wind energy is sensitive to the wind speed, to the requirement, a good quality anemometer as wind mast (tower). Unfortunately, there are some errors may occur in the measurements even with proper calibration caused by tower shadow, the nearby obstacles, or even the anemometer tower itself, may cause vibration of the instrument, resulting in measurement error. Previous studies showed that numerical simulation using a mesoscale meteorological model to verify the measurement data. However, the meteorological model has the inherent limitation as the simulation relies on National Centers for Environmental Prediction (NCEP) reanalysis data with relatively coarse resolution, and no data assimilation technique was adopted to improve the accuracy of the simulation. To couple the meteorological model as Weather Research and Forecasting (WRF) with a commercial computational fluid dynamics (CFD) software FLUENT, this study aims to verify the accuracy of measurement data from a wind mast erected offshore near the west coast of Taiwan. The WRF is used to provide velocity profile inlet for unsteady boundary conditions for FLUENT. The results show that FLUENT data output with smooth terrain is closer to measurement data than WRF data. Fluent with higher resolution and strong techniques such as Computer Aided Design (CAD), Finite Volume Method, and many turbulent modeling as Large eddy simulation (LES) and Detached eddy simulation (DES) combined with the appropriate boundary condition, it can provide wind field simulation results in more accuracy. In addition, this study also examined the physical characteristics of a turbulent boundary layer with the CFD methods employed. Particularly, the region near the wall where the viscous effect dominates can affect the results and fidelity of numerical solutions. However, the numerical results indicated that the affected region is rather insignificant in comparison with the entire thickness of the boundary layer.
論文目次 ABSTRACT I
ACKNOWLEDGEMENTS II
TABLE OF CONTENTS III
LIST OF TABLES VI
LIST OF FIGURES VII
NOMENCLATURE XII
CHAPTER 1. THE ATMOSPHERIC BOUNDARY LAYER AND LITERATURE REVIEW 1
1.1 The Atmospheric Boundary Layer characteristics 1
1.1.1 What is the Atmospheric Boundary Layer (ABL)? 1
1.1.2 Wind and Flow 1
1.1.3 A classification scheme for meteorological phenomena 3
1.1.4 Significance of the Atmospheric Boundary Layer [1] 4
1.1.5 Wind filed in ABL 4
1.2 Literature review 5
1.2.1. Atmospheric Turbulent Flow Solutions Coupled with a Mesoscale Weather Prediction Model.[5] 5
1.2.2 Study on the Micro-scale simulation of wind field over complex terrain by RAMS/FLUENT modeling system. [6] 6
1.2.3 Application of FLUENT on fine-scale simulation of wind field over complex terrain. [7] 7
1.2.4. An application of the RAMS/FLUENT system on the multi-scale numerical simulation of the urban surface layer—A preliminary study. [8] 8
CHAPTER 2. THEORIES AND METHODOLOGY 9
2.1 The Weather Research & Forecasting Model (WRF) 9
2.2 Tower mast 9
2.3 The approaches to describe physical phenomena of fluid 11
2.3.1 Experimental fluid dynamics (EFD) 11
2.3.2 Analytical fluid dynamics (AFD) 12
2.3.3 Computational fluid dynamics (CFD) 12
2.4 Characterizing Turbulence 13
2.4.1 Mean and turbulent part 13
2.4.2 Space and time series 13
2.5 Turbulence modeling 16
2.5.1 Large Eddy Simulation (LES) 17
2.5.1.1 Governing equation 18
2.5.1.2 Subgrid-Scale Model 19
2.5.1.3 Limitation of LES 20
2.5.2 Detached eddy simulation (DES) 21
2.5.2.1 DES with the Spalart-Allmaras (SA) model 21
2.6 Numerical method in FLUENT 22
2.6.1 Finite Volume Method 23
2.6.2 Interpolation methods 24
2.6.2.1 Linear interpolation 24
2.6.2.2 Bilinear interpolation 25
2.6.3 User Defined Function 25
2.6.4 Boundary conditions 26
2.6.4.1 Inlet conditions: 26
2.6.4.2 Outlet conditions: 27
2.6.4.3 Other boundary conditions: 27
CHAPTER 3. GRID GENERATION 29
3.1 Basic of grid generation 29
3.2 Classification of Grid: 30
3.3 Grid quality 31
3.3.1 Skewness 31
3.3.2 Smoothness 33
3.3.3 Aspect ratio 33
3.4 The concept y plus (y+) 34
3.4.1 Boundary layer theory: 34
3.4.2 Inner layer details: The law of the wall from F.White [26] 35
3.4.3 Outer layer 36
3.4.4 Wall function approach 37
CHAPTER 4. GENERAL DESCRIBE THE PROBLEM AND THE IMPLEMENTATION PROCESS 41
4.1 General description of the problem 41
4.1.1 Description of WRF/FLUENT simulation 41
4.1.2 Description of WRF simulation 42
4.1.3 Description of FLUENT simulation 43
4.2 Description of grid generation 44
4.2.1 Depending on the number of grid points of WRF. 44
4.2.2 Based on roughness length classification table. 45
4.3 Investigation for the fully developed boundary layer turbulence 45
4.4 Implementation 46
Processing data 47
CHAPTER 5. RESULTS ANALYSIS 48
5.1 Verification accuracy of wind mast (tower) data 48
Testing the boundary condition and time step, wind mast (tower) data at 86 m and 50 m. 48
5.1.1 WRF data 2015-11-02 at 86 m height 48
5.1.2 WRF 2015-11-02 at 50 m height 58
5.1.3 WRF data 2016-02-05 at 86 m height 59
5.1.4 WRF data 2016-02-05 at 50 m height 61
5.2 Characterizing of the atmospheric boundary layer (ABL) or turbulent boundary layer 62
5.2.1 Consideration effect of boundary layer on simulation results. 62
5.2.1.1 Wall y plus 63
5.2.1.2 Y plus alongside vertical height 66
5.2.1.3 The effect of DES model to the results in 3D 68
5.2.1.4 Determination the RANS thickness region in DES 70
5.2.1.5 Friction velocity u_τ 71
5.2.2 Characterizing turbulence 78
5.2.2.1 Spatial series 78
5.2.2.2 Turbulence kinetic energy (TKE) 80
5.2.2.3 Time series 81
CHAPTER 6. CONCLUSION AND FUTURE WORK 85
6.1 Conclusion 85
6.2 Future work 86
REFERENCES 87

參考文獻 [1] R. B. Stull, An introduction to boundary layer meteorology vol. 13: Springer Science & Business Media, 2012.
[2] ftp://ftp.atmos.washington.edu/debbie/Wallace_Hobbs_Dec19_05_proofs/P732951-Ch09.pdf.
[3] http://www.goes-r.gov/users/comet/tropical/textbook_2nd_edition/navmenu.php tab_2_page_8.1.0.htm.
[4] G. Crasto, "Numerical simulations of the atmospheric boundary layer," Universita degli Studi di Cagliari: Cagliari, Italy, 2007.
[5] E. Leblebici, G. Ahmet, and I. H. Tuncer, "Atmospheric turbulent flow solutions coupled with a mesoscale weather prediction model," in Eccomas special Interest Conference, 3rd South-East European Conference on Computational Mechanics,(Kos Island Greece), 2013.
[6] L. Li, L.-J. Zhang, N. Zhang, F. Hu, Y. Jiang, C.-Y. Xuan, et al., "Study on the micro-scale simulation of wind field over complex terrain by RAMS/FLUENT modeling system," Wind and Structures, vol. 13, p. 519, 2010.
[7] L. Z. Lei Li, Ning Zhang, Fei Hu , Yin Jiang , WeiMei Jiang, "Application of FLUENT on fine-scale simulation of wind field over complex terrain," Plateau Meteorology, vol. 3, p. 010, 2010.
[8] L. Li, F. Hu, J. Jiang, and X. Cheng, "An application of the RAMS/FLUENT system on the multi-scale numerical simulation of the urban surface layer—A preliminary study," Advances in Atmospheric Sciences, vol. 24, pp. 271-280, 2007.
[9] I. A. Pérez, M. L. Sánchez, M. García, and B. de Torre, "Comparison between measurements obtained with a meteorological mast and a RASS sodar," in Proc. Third Int. Conf. on Experiences with Automatic Weather Stations, 2003.
[10] http://www.taiwangenerations.com/english/project.php?projectid=8.
[11] J. Y. Chen, H. Y. Tsai, T. S. Leu, and J. J. Miau, "Wind Characteristics Studies of Fuhai Offshore Wind Mast of Taiwan Generations Corporation and its Comparison with Normal Wind Conditions in IEC 61400 " in Taiwan Wind Energy Conference and Academic Seminar, 2016.
[12] http://www.mit.edu/course/1/1.061/www/dream/SEVEN/SEVENTHEORY.PDF.
[13] X. Jiang and C.-H. Lai, Numerical techniques for direct and large-eddy simulations: CRC Press, 2016.
[14] A. F. Ansys, "14.0 Theory Guide," ANSYS inc, 2011.
[15] A. F. Ansys, "Introduction to ANSYS FLUENT, Lecture 6: Turbulence," 2011.
[16] A. Bakker, "Lecture 10-Turbulence Models Applied Computational Fluid Dynamics," Power-Point presentation, 2002.
[17] A. F. Ansys, " 14.0 Theory Guide," ANSYS inc, pp. 106-108, 2011.
[18] B. Caruelle and F. Ducros, "Detached-eddy simulations of attached and detached boundary layers," International Journal of Computational Fluid Dynamics, vol. 17, pp. 433-451, 2003.
[19] https://www.cfd-online.com/Wiki/Finite_volume.
[20] https://en.wikipedia.org/wiki/Linear_interpolation.
[21] https://en.wikipedia.org/wiki/Bilinear_interpolation.
[22] A. Bakker, "Lecture 6-Applied Computational Fluid Dynamics " Power-Point presentation, 2002.
[23] A. Bakker, "Lecture 7-Meshing Applied Computational Fluid Dynamics," 2002.
[24] https://www.learncax.com/knowledge-base/blog/by-category/cfd/basics-of-y-plus-boundary-layer-and-wall-function-in-turbulent-flows.
[25] Y. A. Cengel and J. M. Cimbala, Fundamental and applications: McGraw Hill, New York, 2006.
[26] F. White, Viscous fluid flow. McGraw-Hill series in mechanical engineering: McGraw-Hill New York, 1991.
[27] https://www.computationalfluiddynamics.com.au/tips-tricks-turbulence-wall-functions-and-y-requirements/.
[28] C. Talbot, E. Bou-Zeid, and J. Smith, "Nested mesoscale large-eddy simulations with WRF: performance in real test cases," Journal of Hydrometeorology, vol. 13, pp. 1421-1441, 2012.
[29] A. Honrubia, A. Vigueras, E. Gomez, M. Mejıas, and I. Lainez, "Comparative analysis between lidar technologies and common wind speed meters," in World Wind Energy Conference, 2010.
[30] G. Solari and L. Pagnini, "Gust buffeting and aeroelastic behaviour of poles and monotubular towers," Journal of Fluids and Structures, vol. 13, pp. 877-905, 1999.
[31] S. M. Salim and S. Cheah, "Wall Y strategy for dealing with wall-bounded turbulent flows," in Proceedings of the international multiconference of engineers and computer scientists, 2009.
[32] B. Blocken, T. Stathopoulos, and J. Carmeliet, "CFD simulation of the atmospheric boundary layer: wall function problems," Atmospheric environment, vol. 41, pp. 238-252, 2007.
[33] X. Zhang, "CFD simulation of neutral ABL flows," Danmarks Tekniske Universitet, Risø Nationallaboratoriet for Bæredygtig Energi 8755037437, 2009.
[34] S. Shimada and T. Ohsawa, "Accuracy and characteristics of offshore wind speeds simulated by WRF," Sola, vol. 7, pp. 21-24, 2011.
[35] O. Krogsæter and J. Reuder, "Validation of boundary layer parameterization schemes in the weather research and forecasting model under the aspect of offshore wind energy applications—Part I: Average wind speed and wind shear," Wind Energy, vol. 18, pp. 769-782, 2015.

論文全文使用權限
  • 同意授權校內瀏覽/列印電子全文服務,於2019-01-01起公開。
  • 同意授權校外瀏覽/列印電子全文服務,於2022-01-01起公開。


  • 如您有疑問,請聯絡圖書館
    聯絡電話:(06)2757575#65773
    聯絡E-mail:etds@email.ncku.edu.tw