تقنية التحكم الخامل بالجريان فوق شفرة توربين رياح ذات حافة خلفية حادة
A Passive Flow Control Technique Over a Wind Turbine Blade with Blunt Trailing Edge
- الباحث
- حمزة ماجد جعفر
- المشرف
- ليث سلمان - عبد الكريم عباس خضير
- الجامعة
- الجامعة التكنولوجية
- الكلية / القسم
- قسم الهندسة الميكانيكية / الهندسة الميكانيكية
- الشهادة
- ماجستير
- السنة
- 2023
- لغة الرسالة
- انكليزي
- الكلمات المفتاحية
- Passive flow control;Wind turbine blade;Blunt trailing edge;Aerodynamics
Abstract
This research, conducted at the University of Baghdad's Department of Aeronautical Engineering, embarked on an in-depth experimental and numerical investigation into the aerodynamic behavior of the DU97-W-300 airfoil and its subsequent modifications, primarily focusing on wind turbine applications. Utilizing the wind tunnel facility, both standard and modified airfoils, encompassing blunt, optimum slotted blunt configurations, were meticulously examined across a range of angles of attack (0°, 4°, 8°, 10°, 12°, 14°, 18°, and 20°) at a consistent Reynolds number of 5 × 105. The study employed ANSYS Workbench Fluent software to analyze the aerodynamic characteristics of these airfoils. This software shed light on flow behavior, pressure distribution, Turbulence Kinetic energy, and more. While there was a significant alignment between the numerical and experimental data at lower angles of attack, discrepancies became evident at higher angles, possibly due to factors like turbulence and manufacturing variations. It's noteworthy that theoretical models, despite their rigor, might not always mirror real-world conditions. For instance, the average error observed was 12.6% for the standard airfoil and varied for the modified versions, highlighting the need for continuous error analysis and refinement of both modeling and experimental methods. The aerodynamic performance of an airfoil is significantly influenced by its modification factor and trailing edge thickness. Some modifications led to a pronounced lift improvement, especially in configurations like K=0 and H=6. Introducing a slot in the blunt trailing edge of the DU97-W-300 airfoil brought about significant changes in its aerodynamics, Introducing a slot in the blunt trailing edge of the DU97-W-300 airfoil significantly alters its aerodynamic characteristics. At angles of attack α≤10∘, minimal changes in the lift coefficient were noted. Conversely, for α≥10∘, a significant decrease in the lift coefficient was observed, significantly as the slot width increased. The slot inlet position is crucial for optimal aerodynamic performance, with the position δ=2.5%c being most effective for a blunt ratio of 3% and δ=7.5%c for a blunt ratio of 6%. Furthermore, the Integrated L-shape Slotted Blunt Enhancement (ILSSBE) technique, which integrates the Gurney flap and Splitter Plate, showcased substantial improvements in the aerodynamic characteristics of wind turbine blades. Specifically, the ILSSBE design yielded a notable increase in lift (cl) by 31.7%, drag (cd) by 52.6%, and an improved lift-to-drag ratio (cl/cd) by 6.72%. Additionally, the ILSSBE H=3% GF=1% SP=3% design resulted in a Pc gain of 0.108 and a γ gain enhancement of 33.16%. At the H=6% blunt ratio, the ILSSBE H=6% GF=1% SP=3% registered a Pc gain of 0.237 and a γ increment of 69.65%. The study also delved into the impact of a low Reynolds number (0.5e6) on aerodynamic behavior. At this Reynolds number, most designs displayed an increase in lift until an angle of attack primarily between 10° to 12°, followed by a decrease, signaling a stall. The ILSSBE H=6 design, in particular, showcased the highest lift, signifying optimal aerodynamic efficiency at this Reynolds number. Moreover, the efficiency, represented as cl/cd, was notably higher for designs like the Opt. Slotted Blunt H=6 at a Reynolds number of 0.5e6. As the Reynolds number increased to 3e6, the disparity in efficiency between designs diminished, though the Opt. Slotted Blunt H=6 still remained a standout design. In essence, this research provides a holistic understanding of the aerodynamic intricacies of the DU97-W-300 airfoil and its modifications. The derived insights, particularly the notable improvements in specific configurations and the differences between experimental and numerical data, are crucial for the future development and optimization of wind turbine blade designs, aiming for enhanced efficiency across various wind conditions.
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