Flow Analysis and Application on the Performance Improvement of Wind Turbine Using Rifled/Unrifled Multi-Stage Rotary Rotors and Side-By-Side Blades

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基本資料

Project title

Code/計畫編號

NSC101-2221-E019-029

Translated Name/計畫中文名

多級數轉子、不同間隙葉片及其受膛線調控之流場分析並應用於風機效能提升

Project Coordinator/計畫主持人

Shun-Chang Yen

Funding Organization/主管機關

National Science and Technology Council

Department/Unit

Department of Mechanical and Mechatronic Engineering

Website

https://www.grb.gov.tw/search/planDetail?id=2588921

Year

2012

Start date/計畫起

01-08-2012

Expected Completion/計畫迄

01-07-2013

Bugetid/研究經費

630千元

ResearchField/研究領域

機械工程

"本計劃書擬議一個系統性的實驗方法，利用多級數轉子(Multi-stage rotary rotors)及變化葉片與葉片間隙(Side-by-side blade)的被動式流體調控機制，並將葉片表面加工施以膛線化(Rifle mechanism)來調控風機葉片的流場，進行對風機效能提升之研究。申請人基於先前對於風扇散熱、機翼氣動力特性、鈍體間不同排列等的研究與實務經驗；發現在特定風機葉片形狀下，葉片與葉片之間的幾何配置，決定了風機效能。因此可藉由葉片與葉片的各種配置，及葉片攻角、旋轉角、膛線化與雷諾數條件下，提升風機效能。本計畫將嘗試，如能以「應用」層面的觀點，結合申請人先前研究的結果，在葉片(NACA 0012)翼尖為梢小翼(Winglet)的角度及翼根連結處 (Junction)可變化特性下，發展調控葉片間不同幾何配置與膛線的設計，進而增進風機效能 (Wind-turbine efficiency)之提升。相信在能源開發上有極高的價值與應用。有鑑於此，在此專題研究計畫中；第一年中，進行多級數轉子(Multi-stage rotary rotors)縱列排列(Tandem)方式的調控研究，以不同轉子(Stage rotary)前、後構置於風洞測試區，進行不同級數轉子的研究。建立一套可以改變轉子與轉子間的相對位置(Spacing ratio)的系統性幾何配置機構，嘗試在各種不同的幾何配置、葉片攻角與雷諾數條件下，調制轉子流場與尾流渦漩性質。過程中將以煙線流場可視化技術、PIV 量測系統、拓樸理論的分析應用、熱線風速儀、六力平衡儀量測氣動力性能，等交互應用，以尋找出最佳化的設計規則與操作條件，並探討多級數轉子調控的流場行為、幾何配置選取、氣動力性能、紊動特性、以及非穩態流動與尾流的調制能力。並將最佳相對位置(Spacing ratio)結果，延續給“變化葉片與葉片間隙”的流動控制機構，俾利下一年度計畫使用。第二年中，繼而將第一年的研究結果應用於，進行變化葉片與葉片間隙(Side-by-side blade) 之流動控制方式，以葉片左、右不同構置(Side-by-side)於風洞測試區，進行變化葉片與葉片間隙(Gap ratio)研究。調制葉片與葉片間的表面流場與提高氣動力性能，並同時回饋前一年所得到不同級數轉子的研究時的最佳結果。探討葉片與葉片間左右構置對風機葉片的影響。研究方式以油膜觀察葉片與葉片間表面流場的特徵模態；及以熱線風速儀偵測葉片與葉片間的流場行為，包含由壓力及速度梯度所形成的渦街(Vortex street)及剪流層不穩定波(Shear layer instability)之間機制的差異。PIV 系統以量化的量測時間相關的非穩態流之演化過程以及與漩渦尾流之交互作用；利用六力平衡儀量測氣動力性能，比對兩個級數轉子之間的結果。將流體穿過葉片與葉片間不同間隙比時，葉片的表面流場、尾流行為、與氣動力特性的關聯性做討論；找出葉片與葉片間隙比的最佳值。將上一年度的多級數轉子相對位置(Spacing ratio)與本年度的葉片與葉片間隙(Gap ratio)的最佳比相結合；俾利下一年度計畫，進行風力發電時，風機葉片、轉子之調控的進行。第三年中，回饋與彙整前二年所得到的結果，在不同級數轉子相對位置(Spacing ratio)與葉片與葉片間隙(Gap ratio)的最佳化下；再將葉片表面加工，施以V 型溝槽型成膛線化(Rifle mechanism)來調控流場的條件下；結合設計、開模、製造出實體風機，直接進行風力發電之測試。過程中，將風機構置於風洞測試區，進行風力發電研究；以風機葉片驅動步進馬達做為發電機使用，類永磁式發電機原理；並以線圈在固定磁場中轉動產生電流脈波，經倍壓器轉為直流電壓輸出；再將電力輸入至充電電路系統中。實驗過程以不同轉速、風速、風向條件下擷取風力發電系統產生的電壓與電流，並計算風能產生的功率。並輔以風機理論分析推算最佳效能之風力發電。可以預期的，直接進行風力發電之測試的效果與風機葉片的流場特性，將可回饋至前二年風機葉片幾何配置的控制機構。以便進一步改善風機葉片幾何配置機構與風力發電的效能相結合，將設計方法與規範作有系統相關性的統整與討論。" "This project experimentally utilizes the multi-stage rotary rotors and side-by-side blades to passively modulate the flow behaviors. The spacing ratio between the rotor and gap ratio between the blades will be changed to improve the wing performance. With the previous researches on the cooling efficiency of fans, aerodynamic performance of forward/backward swept wings and the wake-flow characteristics of bluff-bodies, the applicant found that the geometrical arrangement (tandem or side-by-side) and the configuration (spacing ratio, gap ratio, angle of attack, rotation angle and rifle mechanism) of the specific wing airfoils (NACA 0012) to change the surface-flow and wake-flow patterns. Furthermore, the applicant has many researches about the local flow behaviors on the global aerodynamic performance by changing the winglet dihedral angle or the sweep angle near the wing-junction. This project will utilize the previous results to test and design the blade geometrical arrangement. Furthermore, the optimum design factors and rotor/blade arrangement on wind-turbine performance will be considered. This project includes three-stage experiments and will be performed in three years. In the first year program, the multi-stage rotary rotors placed in tandem to modulate the flow behaviors. The tandem rotary rotors will be tested in a wind tunnel and the spacing ratio between these rotors will be changed to find the effect of spacing ratio on the flow-field/wake-flow around/behind the rotors. Moreover, the angle of attack of rotor blade and Reynolds number will be varied to investigate their effects on flow behaviors. The flow measurements and analysis schemes include the smoke-wire flow visualization, particle image velocimetry (PIV), hot-wire anemometry, six-force balancer and topological analysis. Additionally, the flow patterns, turbulence intensity (T.I.), lift/drag/pitching-moment coefficients and wake vortex-shedding frequency will be investigated. Finally, at the end of first year, the optimum spacing ratio between the tandem rotors will be reported and will be utilized in the next stage. In the second year program, the wing blade will be placed side by side to modulate the flow behaviors. The gap ratio between these two side-by-side wing blades will be changed to modulate the surface-flow behaviors and improve the aerodynamic performance. Furthermore, the results of multi-stage rotary rotors will be included for comparison. The surface oil-flow visualization reveals the characteristic flow patterns on the wing blades. The hot-wire anemometer detects the vortex-street behaviors and the shear-layer instability between/behind these wing blades. The particle image velocimetry (PIV) system quantify the time-related vortex-shedding evolution and the wake-flow structures. Furthermore, a six-force balancer will be utilized to measure the lift, drag and pitching moment. Moreover, the effect of upstream turbulence intensity (T.I.) on the surface-flow structures, wake-flow patterns and aerodynamic performance will be analyzed and discussed. Finally, the optimum gap ratio derived and compared from the tandem multi-stage rotary rotors and side-by-side wing blade will be utilized in the third-year program. In the third year program, the swirling-flow mechanism will be utilized. With the previous studies, the rifled v-grooves will be milled on the wing surface. The flow behaviors and wing performance modulated by the rifle mechanism will be visualized and analyzed using the measurement schemes utilized in the previous two year. Furthermore, the applicant will utilize the geometrical and operation parameters obtained from the previous two-year results. The optimum spacing ratio for the tandem rotary rotors and the optimum gap ratio for the side-by-side blades will be applied to mold the metal into the wind-turbine blade. Moreover, the generator kit will connect to the wind-turbine model to generate the electric power. The fabricated wind turbine will be installed in a wind tunnel to control the flow conditions. The permanent-magnet generator will generate the electric power when the motor is driven by the wind turbine. Furthermore, the output voltage and current are recorded to calculate the output power of power generator. In the power analysis, the rotation speeds, upstream velocities and angles of attack of wing blades will be changed. Furthermore, the wind-turbine principle will be utilized to analyze and calculate the optimum wind power. Expectably, the generated power of wind turbine relates with flow characteristics obtained from the previous two-year results. Namely, the geometrical arrangement of wing blades will influence the output efficiency of wind turbine. Finally, this project will systematically present the design procedures, design parameters and discussion on the wind turbine."

Keyword(s)

流動調制
多級數轉子
葉片間隙
膛線化
風機效能
Flow modulation
Multi-stage rotary rotor
Blade gap
Rifle mechanism
Wind-turbine efficiency

DSpace CRIS

Flow Analysis and Application on the Performance Improvement of Wind Turbine Using Rifled/Unrifled Multi-Stage Rotary Rotors and Side-By-Side Blades

基本資料

Description