PROPID 코드 활용 풍력발전기 블레이드 설계 및 CFD 기반 공력특성 비교분석

최서윤,정준희,육래형,하광태,정재호 한국풍력에너지학회 2022 풍력에너지저널 Vol.13 No.3

A methodology of wind turbine blade design has been established with PROPID code, which is an aerodynamic blade design tool developed by UIUC. PROPID code can design and analyze a wind turbine blade in a steady state flow. The methodology of wind turbine blade design includes an initial blade concept design, airfoil selection, basic design, and detailed design steps. Inverse design and performance analysis of the 2.3 MW U113 wind turbine blade was performed to verify the wind turbine blade design methodology. The differences in calculated power between PROPID code and GH Bladed code are under 1.0% in all wind conditions. Both blade shape design and performance analysis results using PROPID code are accurate. The aerodynamic characteristics of a U113 blade were investigated by computational fluid dynamics. Separation flow was captured by a Reynolds-averaged Navier-Stokes steady flow simulation using ANSYS CFX code. The numerical aerodynamic analysis methodology was verified by comparing the analysis results through CFD with BEMT-based program GH Bladed code results. Therefore, the blade design methodology will be applied to develop a super-capacity 20 MW wind turbine blade in the future.

생체 영감을 활용한 블레이드 디자인 제언: 수직축 풍력발전 블레이드 디자인 중심으로

임준빈 한국인더스트리얼디자인학회 2024 산업디자인학연구 Vol.18 No.1

연구 배경: 현재 소형 풍력발전은 전력 생산성이 떨어져 보편화되지 못하였지만, 소형 풍력발전을 고속도로, 지하철 터널 등에 병렬로 다수 설치한다면, 상업용에 가까운 에너지를 얻을 수 있을 거라는 단순한 생각에서 연구가 시작되었다. 따라서 이를 위한 ‘고효율 블레이드 디자인’이 필요하여 연구되었다. 연구 방법: 본 연구는 실제 블레이드를 제작하여 실증적 연구하였으며 다수의 사례를 통해 귀납적 추론으로 진행되었다. paddle 형 항력 블레이드와 NACA 0011 프로파일을 활용한 블레이드, 이를 어류의 몸동작 형태로부터 영감을 받아 프로파일을 휜 블레이드(Bent NACA 0011) 등 3종을 제작하여 비교 실험하였다. 연구 결과: 항력 블레이드의 회전 속도는 고속으로 상승하는 장점에 비해 풍속을 초과하지 않았다. NACA 0011은 이론적으로 풍속을 초과한다고 하였지만 풍속에 근접한 수준으로 미미하였다. Bend NACA 0011은 회전 시작 2분 40초경 풍속을 초과하여 고속으로 회전하였다. 결론: 생체영감으로 설계된 Bent NACA 0011 블레이드의 결과를 통해 회전 방향으로 휘어진 형태인 블레이드가 수직축 풍력발전 블레이드로 효율적임을 확인하였다. 항력 블레이드는 효율이 낮다고 알려졌음에도 저속의 풍속에서도 기동하고 빠르게 상승하는 것을 통해 많이 활용되는 이유를 파악하였다. Background: Currently, small wind power generation is not common due to low power productivity, but the study began with the simple idea that close to commercial energy could be obtained if a large number of small wind power generation was installed in parallel on highways and subway tunnels. Therefore, a 'high-efficiency blade design' was needed for this study. method: Research method: This study was conducted empirically by manufacturing actual blades and conducted by inductive reasoning through several cases. Three types were manufactured and compared: a paddle-type drag blade, a blade using the NACA 0011 profile, and a Bent NACA 0011 blade that was inspired by the shape of the fish's body movements. Results: The rotational speed of the drag blade did not exceed the wind speed compared to the advantage of rising at a high speed. NACA 0011 was theoretically said to exceed the wind speed, but it was insignificant at a level close to the wind speed. Bent NACA 0011 exceeded the wind speed and rotated at high speed around 2 minutes and 40 seconds after the start of the rotation. Conclusion: Through the results of the Bent NACA 0011 blade designed as bioinspiration, it was confirmed that it was efficient to bend the blade rotating around the vertical axis in the rotation direction. The reason why drag blades are widely used by maneuvering even at low wind speeds was identified.

사이드펄링을 활용한 과풍속제어장치에 대한 풍동시험 연구

조태환,김양원,장일영,박철완,김정환 한국풍력에너지학회 2017 풍력에너지저널 Vol.8 No.2

A wind tunnel test for the side-furling device that was used for a horizontal type small wind turbine to reducethe output power in a high wind speed condition was conducted in a 5 m × 3.75 m open-jet test section. Asimple experimental wind turbine model with a “MEXICO blade” and electric motor was used to simulate thesmall wind turbine system. The furling force of the tail was measured by a force sensor installed on the furlingarm and the yawing moment of the turbine was measured by a moment sensor installed on the turbine strut. The turbine power was calculated by using the torque of the rotating axis and the rotational speed of the blade. Force characteristics of the tail system were studied by changing the arm length, wind speed and flow direction. Moment characteristics of the nacelle and blade system were studied by changing the offset distance, wind speedand RPM. Moment equilibrium conditions for the typical wind speed were estimated from those test results andconfirmed by a fixed-tail-angle test. A free-tail-angle test was also conducted to verify the effect of theside-furling device in high wind speed conditions.

소형 풍력 터빈 블레이드 재료로서 블래더 가압 방식 몰드 성형 프리프레그의 타당성

이보건,서성원,송명호 한국전산구조공학회 2020 한국전산구조공학회논문집 Vol.33 No.2

풍력터빈 블레이드는 바람의 운동에너지를 축일로 변환하는 장치로서 상대적으로 고속 회전하면서 양력과 항력의 다양한 하중 조합과 진동에 견딜 수 있도록 내구 강도가 큰 경량의 재료를 선택하여 강성을 증가시키는 구조를 갖도록 설계되어야 한다. 본 연구는CFRP 프리프레그를 사용하여 소형 풍력 블레이드를 제작하는 경우 공정 시간을 단축하는 기술을 개발하려는 목적으로 수행되었다. QBlade 수치해석 프로그램을 사용하여 블레이드의 형상을 결정하였다. 주어진 풍속에서 바람에 의해 부가되는 양력과 항력을 계산하는 유체역학 수치해석을 수행하고, 대표적인 블레이드 구조에 대해 블레이드 외피 재료에 가해지는 폰미세스 응력을 예측하는 재료역학 수치해석을 수행하였다. 인장 강도 시험의 불확실도를 개선하기 위해 ASTM D638 규정을 수정하여 새로운 시편의 형상을 제안하였고, 기존 형상의 인장 강도와 유사한 평균값을 얻되 파단 위치의 재현성이 향상됨을 확인하였다. 일련의 실험을 통해 소형 풍력블레이드의 제작에 블래더 가압 방식을 적용하면 충분한 내구 강도를 확보하면서 공정시간을 단축할 수 있음을 확인하였다. The wind turbine blades should be designed to possess a high stiffness and should be fabricated with a light and high strength materialbecause they serve under extreme combination of lift and drag forces, converting kinetic energy of wind into shaft work. The goal of this studyis to understand the basic knowledge required to curtail the process time consumed during the construction of small wind turbine blades usingcarbon fiber reinforced polymer (CFRP) prepeg composites. The configuration of turbine rotor was determined using the QBlade freewareprogram. The fluid dynamics module simulated the loads exerted by the wind of a specific speed, and the stress analysis module predicted thedistributions of equivalent von Mises stress for representing the blade structures. It was suggested to modify the shape of test specimen fromASTM D638 to decrease the variance in measured tensile strengths. Then, a series of experiments were performed to confirm that the bladdercompression molded CFRP prepreg can provide sufficient strength to small wind turbine blades and decrease the cure time simultaneously.

고유익형 KA2가 적용된 풍력 블레이드의 회전토크와 추력에 익형의 항력이 미치는 영향 분석

강상균,박성수,이상일,이장호 한국풍력에너지학회 2021 풍력에너지저널 Vol.12 No.1

Many studies have been conducted on the design of wind turbine blades and the several forces necessary for the operation of a wind turbine and its integrated load analysis such as thrust and torque generated at the design point. However, studies on the effect on such several forces by the drag force of a horizontal axis wind turbine blade have not been sufficient. The analysis of the drag effect of an airfoil on the rotational torque and thrust of wind turbine blades requires more precise design performance and drive performance of wind turbines. Therefore, it is necessary to review the degree of effect of airfoil drag force on rotational torque and thrust during the development of wind turbine blades. In this study, a wind turbine blade with the original airfoil KA2 was developed and manufactured for a performance test and the drag effect of an airfoil on the rotational torque and thrust of the horizontal axis wind turbine blade was analyzed. It was confirmed that the drag effect on torque is larger than that of thrust and that the effect of the drag force to the lift force is larger from the root to the tip.

풍력 발전기 블레이드의 구조 개선에 대한 연구

은원종,심지수,박철우,신상준 한국풍력에너지학회 2016 풍력에너지저널 Vol.7 No.1

The wind power energy has been suggested as alternative energy source because it is economically more feasible than other alternative energy technologies. The size of commercial wind turbines has dramatically increased to improve their energy conversion efficiency. The wind turbine blade loads become more important as the wind turbines increase in their size. The modern large-size wind turbine blades generally use sandwich structures and thick laminates to withstand the aerodynamic loads. And the biplane blade design was proposed to use a biplane inboard region to improve overall performance of large blades. The individual pitch control (IPC) facilitates structural load reduction without blade shape alteration. Active flow control methods, such as trailing-edge flap, adaptive compliant wing, micro-tab, have been proposed as viable and effective devices for active load control applications. In order to alleviate the wind turbine blade loads, various researches are under going.

PSO를 이용한 풍력발전 블레이드의 공기역학적 최적설계

리껀,박명성,김영철,백태현 한국기계기술학회 2017 한국기계기술학회 학술대회논문집 Vol.2017 No.04

The object of research in Based on 1.5MW wind turbine blade. This paper has carried out the aerodynamic shape optimization design of wind turbine blade. Based on the aerodynamic basic theory of wind turbine blade design and combined with particle swarm optimization algorithm, the design optimization model of the aerodynamic shape of blade is established. The calculation programs are written by use of MATLAB and calculate chord length and torsion angle of the blade. Then the shape of wind turbine blade is obtained. As research we can know that the chord length is decreased after optimization design of wind turbine blade, The optimized blade not only meets the actual manufacturing requirement, but also has the largest wind energy utilization coefficient.

정격풍속 이하에서 풍력터빈의 윈드쉬어 추력 동하중 개발

임채욱(Chae-Wook Lim) 대한기계학회 2016 大韓機械學會論文集A Vol.40 No.4

풍력터빈이 ㎿급으로 대형화되면서 블레이드의 길이가 40미터 이상으로 길어지게 되어, 로터 블레이드가 회전할 때 블레이드에 발생하는 비대칭하중이 증가하게 되었다. 윈드쉬어, 타워 섀도우, 난류풍속 같은 요소들은 블레이드에 이런 비대칭하중 발생에 영향을 미친다. 본 논문은 원드쉬어로 인해 블레이드에 발생하는 추력변동에 의한 동하중을 추력계수를 이용하여 모델링하는 방법에 관한 것이다. 이를 위하여 “윈드쉬어 추력변동 계수”를 정의 및 도입하고, 2㎿ 육상용 풍력터빈을 대상으로 정격이하의 풍속에서 윈드쉬어 추력변동 계수값을 구하여 분석한다. 구해진 “윈드쉬어 추력변동 계수”와 추력계수를 이용하여 Matlab/Simulink에서 윈드쉬어 동하중 모델을 구현하고, 윈드쉬어에 의해 세 블레이드에 작용하는 추력변동을 추력계수와 “윈드쉬어 추력변동 계수”를 동시에 이용하여 표현할 수 있음을 보인다. As wind turbines are getting larger in size with multi-㎿ capacity, the blades are getting longer, over 40 m, and hence the asymmetric loads produced during the rotation of the rotor blades are increasing. Some factors such as wind shear, tower shadow, and turbulence have an effect on the asymmetric loads on the blades. This paper focuses on a method of modeling the dynamic load acting on a blade because of thrust variation under wind shear. A method that uses thrust coefficient is presented. For this purpose, “wind shear coefficient of thrust variation” is defined and introduced. Further, we calculate the values of the “wind shear coefficient of thrust variation” for a 2 ㎿ on-shore wind turbine, and analyze them for speeds below the rated wind speed. Then, we implement a dynamic model that represents the thrust variation under wind shear on a blade, using MATLAB/Simulink. It is shown that it is possible to express thrust variations on three blades under wind shear by using both thrust coefficient and “wind shear coefficient of thrust variation.”

강재 풍력 터빈 타워의 상부구조 모델링 방법에 따른 고유진동수 특성에 대한 고찰

이윤우 ( Yun Woo Lee ),최준호 ( Jun Ho Choi ),강성용 ( Sung Yong Kang ),강영종 ( Young Jong Kang ) 한국복합신소재구조학회 2014 복합신소재구조학회논문집 Vol.5 No.3

Wind turbine tower has a very important role in wind turbine system as one of the renewable energy that has been attracting attention worldwide recently. Due to the growth of wind power market, advance and development of offshore wind system and getting huger capacity is inevitable. As a result, the vibration is generated at wind turbine tower by receiving constantly dynamic loads such as wind load and wave load. Among these dynamic loads, the mechanical load caused by the rotation of the blade is able to make relatively periodic load to the wind turbine tower. So natural frequency of the wind turbine tower should be designed to avoid the rotation frequency of the rotor according to the design criteria to avoid resonance. Currently research of the wind turbine tower, the precise research does not be carried out because of simplifying the structure of the other upper and lower. In this study, the effect of blade modeling differences are to be analyzed in natural frequency of wind turbine tower.

MG-set 기반의 풍력터빈 동적 시뮬레이터 개발

원병철,전태수,백인수 한국풍력에너지학회 2021 풍력에너지저널 Vol.12 No.4

In this paper, a dynamic simulator based on an MG set was implemented for a scaled wind turbine model with a rated power of 40 W with an operating mechanism similar to that of a MW-class large wind turbine. A test bench constituting the simulator hardware was initially designed and manufactured by Carlo L. Bottasso's research team at the Technical University of Munich. In this study, part of the test bench was modified and redesigned, and a simulator capable of dynamic simulation was developed by applying a GUI for operation and monitoring, and a dynamic driving algorithm and turbine control algorithm. A DC motor is connected to the main shaft to emulate the rotor rotation. Also, in order to simulate the change in the rotor rotation speed according to the change in wind speed, motor speed control was performed using a numerical model of the wind turbine based on MATLAB Simulink. The generator part was directly applied to the MG set together with the nacelle part of the target wind turbine scale model. To verify the performance of the MG set-based dynamic simulator, it was compared with the existing MATLAB Simulink dynamic simulation model. The main performance data between the experimental results and the MATLAB Simulink-based dynamic simulation were compared, and an error within 1 % was confirmed. Using the MG set-based dynamic simulator built in this study, it was confirmed that it was possible to verify the performance of the wind turbine controller for dynamic wind in the laboratory before a wind tunnel test.