簡易檢索 / 詳目顯示

回結果列表
研究生： 黃進帽
Huynh, Tan Mao
論文名稱： 重型卡車裝上噴嘴式減阻裝置後的計算模擬分析
Computational Simulation of Heavy Truck Model with Corner Nozzle Drag Reduction Device
指導教授： 陳世雄
Chen, Shi-Hsiung
學位類別： 碩士
Master
系所名稱： 工學院 - 航空太空工程學系
Department of Aeronautics & Astronautics
論文出版年： 2017
畢業學年度： 105
語文別： 英文
論文頁數： 120
中文關鍵詞： 計算流體力學 、空氣動力 、角落噴嘴 、轉折角 、面積比
外文關鍵詞： CFD, aerodynamics, corner nozzle, effusive angle, area ratio
相關次數： 點閱：105  下載：9 
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

    • 重型卡車的油耗代表著能源消耗中很大的比重，它接近火柴盒外型的車體在高速行駛的時候空氣的阻力超過了因重量產生的摩擦阻力，此空氣阻力有很大一部份來自於卡車尾部的貢獻。本研究旨在探討如何利用空氣動力學的原理，來降低重型卡行駛中尾部的空氣阻力，進而降低燃油的消耗。使用的設計稱為角落噴嘴，垂直裝置在卡車尾端的左右兩側角落上，它用來平順的導引經過卡車側面的氣流至卡車尾端，並調整卡車背面的壓力，使達到降低空氣阻力的目的。卡車是採用與NASA Ames 實驗中心風洞試驗同樣的GTS 1/8縮小模型，計算流體力學(CFD)的方法在基本的卡車模型上做計算模擬分析，計算的模型是以CATIA建立外型，以軟體ICEM-CFD進行流場網格生成，再用ANSYS-CFX以有限單元法做流場的計算分析, 分別計算未裝置角落噴嘴及裝上角落噴嘴後的阻力，並據以判定角落噴嘴在降低空氣阻力的功效。角落噴嘴由兩片彎曲薄板構成，其性能由兩個重要參數控制：轉折角(α)和面積比(AR)。本研究討論的轉折角從20度到70度，面積比則從1.0到2.0，增量為0.2改變。計算結果顯示，角落噴嘴確實能降低空氣的阻力，不同的α角及AR有不同的空氣阻力降低效果，每個AR都有其相對的最佳α值使其空氣阻力最低，而此α值隨著AR的變大也跟著變大。在本研究中，最大的空氣阻力降低發生在α=60度及AR=2.0的時候，空氣阻力降低了7.609%。

    Heavy truck fuel consumption represents a high percentage in overall energy consumption. Its matchbox-like configuration makes its aerodynamic drag exceed the frictional drag due to its weight. A large portion of the aerodynamic drag is attributed to the drag in the rear end of the truck. The purpose of this research is to study numerically the design of corner nozzles, installed vertically at two corners of the truck’s rear end, for the aerodynamic drag reduction to save fuel consumption. The model of heavy truck in the present study was an 1/8-scale Ground Transportation System (GTS), which was studied experimentally in the 7-by 10-foot NASA Ames wind tunnel facility. Computational fluid dynamics (CFD) method was used to do the numerical simulation. The computational model was created using CATIA CAD file. The numerical method adopted was CFX software for numerical simulation and ICEM-CFD for mesh generation. The simulations were performed on a baseline GTS truck model with and without the add-on corner nozzles. Comparisons were made to see the effectiveness of the corner nozzles. The nozzles in design considerations were made of two curved sheet metals. The performances were determined based on two configuration parameters: the effusive angles from 20 degrees to 70 degrees, and the nozzle outlet to inlet area ratios (AR) from 1.0 to 2.0 at 0.2 intervals. Calculations showed good aerodynamic drag reductions at different percentages. The results indicated that the larger AR has better drag reduction effect. The optimal effective angle for a given AR is proportional to the value of AR. The larger AR has the larger optimal effusive angle. The best design in the present study was found to be 7.609% in drag reduction when AR equals 2.0 and effusive angle is 60 degrees.

    CONTENTS 摘要 i ABSTRACT ii ACKNOWLEDGEMENTS iii CONTENTS iv LIST OF FIGURES vii NOMENCLATURES xiii CHAPTER 1: INTRODUCTION 1 1.1 Background 2 1.2 Literature review 6 1.3 Research Methodology 13 1.4 Motivation 14 CHAPTER 2: PROBLEM DESCRIPTION 17 2.1 Ground Transportation System model (GTS) 17 2.2 Experimental results 20 2.2.1. GTS model in the NASA Ames 7-by 10-Ft Wind Tunnel 20 2.2.2. GTS model in the Texas A&M University Low Speed Wind Tunnel 25 2.3 Computational results 26 2.3.1 Kambiz Salari ‘s computational flow modeling 26 2.3.2 Subrahmanya P.Veluri’s computational flow modeling 28 2.4. Corner nozzle geometry 31 CHAPTER 3: SIMULATION APPROACH 37 3.1 Governing Equations 37 3.2 Reynolds Averages Navier-Stokes Equations 42 3.2.1 Reynolds form of the continuity equation 43 3.2.2 Reynolds form of the momentum equation 44 3.2.3 Reynolds form of the energy equation 44 3.3 Shear stress transport (SST) turbulence model 45 3.4 Wall function approach 47 3.5 Numerical discretization technique 52 3.5.1 Shape function 55 3.5.2 Control Volume Gradients 58 3.5.3 Advection term 58 3.5.4 Diffusion terms 59 3.5.5 Pressure gradient term 59 3.5.6 Mass flows 60 CHAPTER 4: COMPUTATIONAL MODELING 62 4.1 Computational domain construction 62 4.2 Meshing strategy 65 4.3 Pre-simulation set up 72 4.3.1 Physical domain modeling 73 4.3.2 Boundary condition modeling 74 4.3.3 Solver control setting 77 CHAPTER 5: RESULT AND DISCUSSION 79 5.1 Convergence history observation 79 5.2 Aerodynamic drag coefficient 81 5.3 Pressure coefficient 91 5.4 Velocity vector 95 5.5 Pressure Contour 102 5.6 Velocity streamline 109 CHAPTER 6: CONCLUSION AND FUTURE WORK 116 6.1 Conclusion 116 6.2 Future work 117 Reference 118

    Reference
    [1] J. Dings, "The case for the exemption of aerodynamic devices in future type-approval legislation for heavy goods vehicles," European Federation for Transport and Environment AISBL, Belgium, January, 2010.
    [2] K. Salari, "DOE's Effort to improve Heavy Vehicle Aerodynamics through Joint Experiments and Computations," DOE Annual Merit Review, Project ID # VSS006 , May 13-17, 2013.
    [3] R. C. McCallen, K. Salari, J. Ortega, L. DeChant, B. Hassan, C.Roy, W. D. Pointer, F. Browand, M. Hammache, T. Y. Hsu, A. Leonard, M. Rubel, P. Chatalain, R. Englar, J. Ross, D. Satran, J. T. Heineck, S. Walker, D. Yaste, B. Storms, "DOE's Effort to Reduce Truck Aerodynamic Drag-Joint Experiments and Computations Lead to Smart Design," UCRL-CONF-204819, 34th AIAA Fluid Dynamics Conference and Exhibit, Portland, Oregon, United States, 2004.
    [4] R. M. Wood and S. X. S. Bauer, "Single and Low-Cost Aerodynamic Drag Reduction Devices for Tractor-Trailer Trucks," SAE Technical Paper 2003-01-3377, DOI: 10.4271/2003-01-3377, 2003.
    [5] Council of Energy Ministers, "On the Road to a Fuel-efficient Truck: A Guide for Purchasing Aerodynamics for Heavy-Duty Tractors and Trailers," ISBN 978-1-100-50128-4, Her Majesty the Queen in Right of Canada, 2009.
    [6] R. H. Croll, W. T. Gutierrez, B. Hassan, J. E. Suazo, and E. J. Riggins, "Experimental Investigation of the Ground Transportation Systems (GTS) Project for Heavy Vehicle Drag Reduction," SAE Technical Paper 960907, DOI: 10.4271/960907, 1996 .
    [7] B. Hassan, W. T. Gutierrez, W. P. Wolfe, and M. A. Walker, B. G. Ruefer, and J. W. Hurt, "Numerical Prediction of Aerodynamic Drag for Heavy Ground Transportation Vehicles," AIAA -95-1913-CP, 13th Applied Aerodynamics Conference, San Diego, CA, USA, 1995.
    [8] W. T. Gutierrez, B. Hassan, R. H. Croll, and W. T. Gutierrez, "Aerodynamics Overview of the Ground Transportation Systems (GTS) Project for Heavy Vehicle Drag Reduction," SAE Technical Paper 960906, DOI: 10.4271/960906, 1996.
    [9] J. D. Coon and K. D. Visser, "Drag Reduction of a Tractor-Trailer Using Planar Boat Tail Plates," The Aerodynamics of Heavy Vehicles: Trucks, Buses, and Trains, Lecture Notes in Applied and Computational Mechanics, Vol. 19, pp. 249-265, Springer-Verlag Berlin Heidelberg, 2004.
    [10] R. McCallen, T. D. Dan Flowers, and J. Owens, "Aerodynamic Drag of Heavy Vehicles (Class 7-8): Simulation and Benchmarking," SAE Technical Paper 2000-01-2209, DOI: 10.4271/2000-01-2209, 2000.
    [11] Y. Takemori, S. Kato, Y. Masumitsu, Y. Kaya, and T. Mizutani, "Drag Reduction of Bluff-Based Body by Wake Control Vanes ( Effective Utilization of Under Floor Flow )," F2000G357, Seoul 2000 FISITA World Automotive Congress, Seoul, Korea, June 12-15, 2000.
    [12] A. Seifert, O. Stalnov, D. Sperber, G. Arwatz, V. Palei, S. David, I. Dayan, I. Fono, "Large Trucks Drag Reduction using Active Flow Control," AIAA 2008-743, 46th AIAA Aerospace Sciences Meeting and Exhibit, Reno, Nevada, January 7-10, 2008.
    [13] B. L. Storms, J. C. Ross, J. T. Heineck, S. M. Walker, D. M. Driver, and G. G. Zilliac, "An Experimental Study of the Ground Transportation System (GTS) Model in the NASA Ames 7- by 10- Ft Wind Tunnel," NASA/TM-2001-209621, Ames Research Center, Moffett Field, California, 2001.
    [14] K. Salari, J. M. Ortega, and P. J. Castellucci, "Computational Prediction of Aerodynamic Forces for a Simplified Integrated Tractor-Trailer Geometry," AIAA-2004-2253, 34th AIAA Fluid Dynamics Conference and Exhibit, Portland, Oregon, 2004.
    [15] S. Maddox, K. D. Squires, K. E. Wurtzler, and J. R. Forsythe, "Detached-Eddy Simulation of the Ground Transportation System," The Aerodynamics of Heavy Vehicles: Trucks, Buses, and Trains. Lecture Notes in Applied and Computational Mechanics, vol. 19, pp. 88-104, Springer-Verlag Berlin Heidelberg, 2004.
    [16] J. M. Ortega and K. Salari, "An Experiment Study of Drag Reduction Devices for a Trailer Underbody and Base," UCRL-CONF-204489, 34th AIAA Fluid Dynamics Conference and Exhibit, Portland, Oregon, United States, 2004.
    [17] F. Browand, C. Radovich, and M. Bolvin, "Fuel Savings by Means of Flaps Attached to the Base of a Trailer: Field Test Results," SAE Technical Paper 2005-01-1016, DOI :10.4271/2005-01-1016, 2005.
    [18] M. Y. Tsai, "The Study of Using Corner Nozzle Flow for Truck Drag Reduction," Master Thesis, Department of Aeronautics and Astronautics, National Cheng Kung University, 2009.
    [19] W. H. Hucho, "Aerodynamics of Road Vehicles: From Fluid Mechanics to Vehicle Engineering," ISBN 0-408-01422-9, Butterworth-Heinemann Ltd, 1987.
    [20] G. Sovran, T. Morel, and W. T. Mason, "Aerodynamic Drag Mechanisms of Bluff Bodies and Road Vehicles," ISBN 978-1-4684-8436-6, Plenum Press, New York, 1978.
    [21] W. D. Pointer and S. Singh, "Heavy Vehicle Drag Estimation using Commercial CFD Tools," Argonne National Laboratory, The University of Chicago, 2006.
    [22] S. Krajnović, "Improving vehicle aerodynamics for better energy efficiency," Vehicle Aerodynamics Laboratory, Chalmers University of Technology, 2013.
    [23] S. Pereira, "ICEM CFD Tetra/Prism For CFD++ or Fluent," ANSYS, Inc., 2007.
    [24] ANSYS Inc., "ANSYS CFX-Solver Theory Guide," Release 16.0, 2015.
    [25] ANSYS Inc., "ANSYS CFX-Pre User's Guide," Release 16.0, 2015.
    [26] ANSYS Inc., ANSYS CFD-Post User's Guide," Release 16.0, 2015.
    [27] F. R. Menter, "Zonal Two Equation k-ω Turbulence Models for Aerodynamic Flows," AIAA Paper 93-2906, 1993.
    [28] T. Welfers, S. Ginsberg, M. Funcke, M. Hamacher, and R. Matheis, "Design of a Tractor for Optimised Safety and Fuel Consumption," Report 104190, Forschungsgesellschaft Kraftfahrwesen mbH Aachen Body Department, Aachen, 2011.
    [29] Y. S. Sutopo, "Computational Simulation and Flow-Filed Analysis of Heavy Duty Truck Model," Master Thesis, Department of Aeronautics and Astronautics, National Cheng Kung University, 2012.
    [30] L. C. Hou, "The study of gust force on a truck using corner nozzle flow drag reduction device," Master Thesis, Department of Aeronautics and Astronautics, National Cheng Kung University, 2013.
    [31] S. P. Veluri, C. J. Roy, A. Ahmed, R. Rifki, J. C. Worley, and B. Recktenwald, "Joint Computational/Experimental Aerodynamic Study of a Simplified Tractor/Trailer Geometry," Journal of Fluids Engineering, ASME, DOI: 10.1115/1.3155995, 2009.
    [32] R. H. Pletcher, J. C. Tannehill, and D. A. Anderson, "Computational Fluid Mechanics and Heat Transfer," 3rd edition, Taylor & Francis Group, 2013.

    下載圖示 校內：2017-02-20公開
    校外：2017-02-20公開
    QR CODE