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組織工程研究
來源: | 作者: | 發布時間:2013-9-22 14:19:59

鈍尾緣翼型氣動特性分析#
程曉龍1,馬朝臣1,老大中2,王磊磊1,楊策1**
基金項目:高等學校博士學科點專項科研基金(20111101130002)
作者簡介:程曉龍(1989-),男,碩士研究生,風力機減阻
通信聯系人:馬朝臣(1959-),男,教授,葉輪機械氣動熱力學. E-mail: mcc1900@bit.edu.cn
(1. 北京理工大學機械學院葉輪機械研究所,北京 100081; 2. 北京理工大學宇航學院,北京 100081) 5
摘要:本文采用計算流體力學軟件Fluent,選用k-ε湍流模型,對鈍尾緣風力機葉片翼型TR-4000-2000進行數值模擬計算,研究了鈍尾緣的使用對翼型氣動特性的影響。對相同來流速度不同攻角情況下翼型流場進行定常及非定常模擬計算,分析得出翼型升阻力等氣動參數的波動特性、尾緣脫落渦及分離渦周期性運動規律和翼型表面壓力隨時間的波動特性,并10 通過頻譜分析方法確定翼型升阻力系數波動及翼型表面壓力波動同尾緣渦運動之間的對應關系。結果顯示,尾緣脫落渦所引起的翼型表面壓力波動是造成鈍尾緣翼型氣動參數變化的主要原因。在此基礎上,更好的解釋鈍尾緣翼型流場的隨流特性及其變化規律,為進一步研究鈍尾緣翼型增升減阻、失速控制及流動控制奠定了基礎。
關鍵詞:鈍尾緣翼型;數值模擬;升阻力特性;壓力波動



Analysis on Aerodynamic Characteristics of Blunt Trailing Edge Wind Turbine Airfoil
CHENG Xiaolong1, MA Chaochen1, LAO Dazhong2, WANG Leilei1, YANG Ce1 


(1. Turbo Machinery Institute, School of Machanical Engineering, Beijing Institute of Technology, Beijing 100081; 2. School of Aerospace Scientific Engineering, Beijing Institute of Technology, Beijing 100081)
Abstract: In this issue,a blunt trailing edge wind turbine airfoil TR-4000-2000 is numerically investigated by the Computational Fluid Dynamics software FLUENT in the case of k-ε turbulent  model,and the influence caused by the use of blunt trailing edge on aerodynamic characteristics were studied. Steady and unsteady numerical simulation of airfoil flow field in different attack corner was performed,and the fluctuation characteristics of aerodynamic parameters was obtained,such as lift coefficient,drag coefficient and time-dependent pressure on airfoil surfaces. Besides,the periodic movement of shedding vortex and separation vortex was gained,and the corresponding relationship  between fluctuation of lift coefficient,drag coefficient,trailing edge vortex movement and surface pressure fluctuation was determined by the way of frequency analysis. The analytic results show that the pressure fluctuation on airfoil surface caused by shedding vortex in trailing edge is the main reason of aerodynamic characteristics fluctuation. Based on these researches,an overall explanation was given to the characteristics of fluid field and its transformation rules,which build the foundation for further  research such as lift improvement and drag reduction,stall control and flow control.
Key words: Blunt trailing edge airfoil;Numerical simulation;Lift and drag characteristic;Pressure fluctuation


小功率非隔離型單開關雙Buck型三端口變換器#
文剛,陳宇,康勇**
基金項目:高等學校博士學科點專項科研基金資助課題(20120142120026) 作者簡介:文剛(1983-),男,博士生,主要研究方向:電力電子變換拓撲的元件復用規律與應用研究 通信聯系人:陳宇 (1983-),男,工學博士,研究方向包括電力電子電路與控制、軟開關技術等. E-mail: ayu03@163.com
(華中科技大學強電磁工程與新技術國家重點實驗室,華中科技大學電氣學院,武漢 5 430074)
摘要:本文介紹了一種適用于小功率非隔離應用場合的新型雙buck型三端口變換器,該變換器用單個功率開關控制兩路buck電路獨立運行,可用于可再生能源系統中,連接新能源、儲能元件及負載,且具有以下優點:(1)僅包含一個功率開關,可省去復雜的驅動電10 路與散熱系統,電路成本低;(2)通過控制開關器件的占空比和開關頻率實現三端口之間的能量流動,控制電路簡單;(3)電源與負載之間存在直接的能量轉移通路,儲能元件只需平衡差額能量,儲能元件的使用壽命得到延長。本文介紹了所提變換器的電路結構、工作模式及參數設計方法,給出了適用的變帶寬滑?刂撇呗,并在此基礎上分析了能量管理策略。最后通過實驗結果證明以上論述的正確性。 15
關鍵詞:三端口變換器;可再生能源系統;能量管理;滑?刂


Low Power Non-isolated Single-Switch Double Buck Three-Port Converter 20
WEN Gang, CHEN Yu, KANG Yong
(State Key Laboratory of Adwanced Electromagnetic Engineering Technology (AEET) also School of Electrical and Electronic Engineering (SEEE), Huazhong University of Science & technology, Wuhan 430074)
Abstract: A new double buck three-port converter using in low power non-isolated application is 25 presented in this paper. This new converter uses one power switch to control two buck circuits working independently, and can be used in the renewable energy systems to connect the new energy resource, energy storage element and load. The attractive features are: (1) only have one power switch, so the drive circuits are simple, the cooling system is small, and the cost of the device is low; (2) the duty cycle and switching frequency are utilized for balancing the energy 30 among the three ports, and control circuit is simple; (3) the lifespan of the energy storage element can be prolonged, since there is a direct current path from source to load and just the redundant energy need to be processed. The circuit configuration, working modes, and the design method of the converter are introduced, a suitable variable-band sliding-mode controller is proposed, the energy management strategy is analysed, and at last the experimental results are given to prove the 35 theoretical analysis' s validity.
Key words: three-port converter; renewable energy system; energy management; sliding-mode control
Low Power Non-isolated Single-Switch Double Buck Three-Port Converter 
WEN Gang, CHEN Yu, KANG Yong
(State Key Laboratory of Adwanced Electromagnetic Engineering Technology (AEET) also School of Electrical and Electronic Engineering (SEEE), Huazhong University of Science & technology, Wuhan 430074)
Abstract: A new double buck three-port converter using in low power non-isolated application is presented in this paper. This new converter uses one power switch to control two buck circuits working independently, and can be used in the renewable energy systems to connect the new energy resource, energy storage element and load. The attractive features are: (1) only have one power switch, so the drive circuits are simple, the cooling system is small, and the cost of the device is low; (2) the duty cycle and switching frequency are utilized for balancing the energy among the three ports, and control circuit is simple; (3) the lifespan of the energy storage element can be prolonged, since there is a direct current path from source to load and just the redundant energy need to be processed. The circuit configuration, working modes, and the design method of the converter are introduced, a suitable variable-band sliding-mode controller is proposed, the energy management strategy is analysed, and at last the experimental results are given to prove the theoretical analysis' s validity.
Key words: three-port converter; renewable energy system; energy management; sliding-mode control



High-order Siliding Mode Control of Doubly-fed Induction
Generator
Chen Bin, Feng Yong, Zhou Minghao
(School of Electrial Engineering and Automation,Harbin Institute of Technology,
Harbin 150001)
20 Abstract: Doubly-fed induction generator is the most important generator used for VSCF wind
power generation system. so researching on new control strategy to ensure safe, stable and
efficient operation of DFIG has important meaning. As DFIG is a multiple variables, strong
coupling and nonlinear system, which makes it difficult to use traditional linear control strategy to
control the DFIG with good dynamic and static performance. High-order sliding mode control
25 strategy has many important advantages, such as strong robustness,fast convergence,high
tracking accuracy and ability to eliminate the chattering phenomenon existing in the
conventional sliding mode control. In this paper, speed and current controllers of DFIG are
designed based on the mathematical mode of DFIG in d-q synchronous rotating reference frame
and the high-order sliding mode control theory. The validity of the proposed method has been
30 verified by computer simulation.
Keywords: Wind power; Vector control; High-order sliding mode control
High-order Siliding Mode Control of Doubly-fed Induction
Generator
Chen Bin, Feng Yong, Zhou Minghao
(School of Electrial Engineering and Automation,Harbin Institute of Technology,
Harbin 150001)
Abstract: Doubly-fed induction generator is the most important generator used for VSCF wind power generation system. so researching on new control strategy to ensure safe, stable and efficient operation of DFIG has important meaning. As DFIG is a multiple variables, strong coupling and nonlinear system, which makes it difficult to use traditional linear control strategy to control the DFIG with good dynamic and static performance. High-order sliding mode control strategy has many important advantages, such as strong robustness,fast convergence,high
tracking accuracy and ability to eliminate the chattering phenomenon existing in the conventional sliding mode control. In this paper, speed and current controllers of DFIG are designed based on the mathematical mode of DFIG in d-q synchronous rotating reference frame and the high-order sliding mode control theory. The validity of the proposed method has been verified by computer simulation.
Keywords: Wind power; Vector control; High-order sliding mode control



The Comparison And Analysis In The Field Of Isotope Separation Based On PIC
Yan Yuming, Zhao Hailong, Wang Yulong, Zhang Le, Jiang Binhao
(Department of Electrical Engineering School of Electrical Engineering and Automation, Harbin Institute of Technolog, Harbin 150001)
Abstract: Plasma optical mass separation method inherits the advantages of traditional electromagnetic isotope separation method, the theory is an important reformation in the area of isotope separation. The azimuthator is an important part of the mass separator, and the particle-in-cell method is one of the three important methods in the study of plasma. Based on brief analysis to the existing particle-in-cell simulation software, it takes the azimuthator of plasma optical mass separation as the research object, contrasts the simulation results of opening particle-in-cell software OOPIC and the PIC program written by own using the research method of PIC, and analyse the merits and faults of them.
Keywords:  POMS; azimuthator; plasma beam; particle-in-cell

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