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1
DEDA ALTAN, Burcin. "Enhancement of the performance of vertical axis wind rotors with straight blades". European Mechanical Science 7, nr 2 (20.06.2023): 49–55. http://dx.doi.org/10.26701/ems.1246352.
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In this study, it has been aimed to improve the performance of vertical axis wind rotors with straight blades. For this purpose, an additional performance-enhancing setup has been used, placed in front of the vertical axis wind rotor with straight blades, in order to increase the performance. The effects on the rotor performance increase have been investigated numerically by keeping the dimensions of this performance-enhancing additional setup constant, by changing the number of blades of the straight bladed rotor and by changing the blade angles if the straight blades have been angled. Numerical analyzes performed in this study have been validated by experimental literature data. After creating the solid models required for the rotor performance analysis, the computational fluid dynamics (CFD) program ANSYS Fluent has been used. Here, studies have been carried out with two, three and four bladed rotors as the number of blades. As the blade angle, the effects of the angles between 180 and 120 have been examined. As a result of the study with the additional performance setup (APS), it has been determined that the optimum performance has been obtained with the vertical axis rotor with three blades and 150 blade angle. As a final result, it has been determined that the power coefficient obtained from the optimum vertical axis rotor with additional performance setup increased approximately 2.6 times compared to the optimum rotor without setup.
2
Mwanyika, Hegespo H., Yusufu AC Jande i Thomas Kivevele. "Design and Performance Analysis of Composite Airfoil Wind Turbine Blade". Tanzania Journal of Science 47, nr 5 (1.12.2021): 1701–15. http://dx.doi.org/10.4314/tjs.v47i5.18.
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Abstract
Small horizontal axis wind turbine rotors with composite airfoil rotor blades were designed and investigated in the present study in order to improve its performance in low wind speed and low Reynolds number (Re) conditions for standalone system. The geometrical and aerodynamic nature of a single airfoil small horizontal axis wind turbine blade curtails efficient energy harnessing of the rotor blade. The use of composite airfoil rotor blade improves energy production but imposes uncertainty in determining an optimal design angle of attack and the off design aerodynamic behaviour of the rotor. This research investigated the effects of two airfoils used at different sections in a composite blade and determined the blade’s optimal design angle of attack for maximum power generation. The wind turbine rotor blades were designed using blade element momentum (BEM) method and modelled by SolidWorks software. The SG6042 and SG6043 airfoils were used for the composite airfoil blades. Five wind turbines were designed with rotor blades of design angles of attack from 3° to 7°. The five wind turbine blades were simulated in computational fluid dynamics to determine the optimal design angle of attack. The composite airfoil wind turbine blade showed improved performance, whereas, the wind power generated ranged from 4966 W to 5258 W and rotor power coefficients ranged from 0.443 to 0.457. The blade with design angle of attack of 6° showed highest performance.
Keywords: composite airfoil, lift-to-drag ratio, pressure coefficient, Reynolds number, design angle of attack.
3
Li, Yan, Chang Zhao, Chunming Qu, Shouyang Zhao, Fang Feng i Kotaro Tagawa. "Effect of Auxiliary Blade on Aerodynamic Characteristics of Vertical Axis Wind Turbine by Numerical Simulation". International Journal of Rotating Machinery 2019 (21.04.2019): 1–17. http://dx.doi.org/10.1155/2019/8098160.
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In order to improve the aerodynamic characteristics of the Straight-bladed Vertical Axis Wind Turbine (SB-VAWT), a rotor structure with auxiliary blade installed behind the main blade was proposed in this study. To investigate the effects of relative thickness and the fixing angle of the auxiliary blade on aerodynamic characteristics of SB-VAWT, numerical simulations were carried out. Two shapes of NACA 4-digital series blade-section, NACA0018 and NACA0024, were selected as the main blades in this work. Effects of relative thickness and fixing angles of auxiliary blade on the aerodynamic performance of SB-VAWT had been analyzed in detail, which had 5 kinds of relative thickness and 3 kinds of fixing angles combined into 13 working conditions. And the main blades and the auxiliary blades were also decided as the NACA series airfoil with five kinds of relative thickness. Three kinds of fixing angle of auxiliary blade installed behind main blade were used including 0°, 5°, and 10°. The simulations included the output power coefficients, the static torque coefficients, and the flow fields around the main blade and auxiliary blade for both the dynamic and static conditions at some typical azimuth angles. The results show that the auxiliary blade with certain relative thickness and fixing angle can improve the output power characteristics and static torque characteristics of SB-VAWT, which can also provide research reference for improving the performance of VAWT.
4
Nejadrajabali, J., A. Riasi i S. A. Nourbakhsh. "Flow Pattern Analysis and Performance Improvement of Regenerative Flow Pump Using Blade Geometry Modification". International Journal of Rotating Machinery 2016 (2016): 1–16. http://dx.doi.org/10.1155/2016/8628467.
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Regenerative pump is a low specific speed and rotor-dynamic turbomachine capable of developing high heads at low flow rates. In this paper, a numerical study has been carried out in order to investigate the effect of blade angle on the performance of a regenerative pump. Two groups of impellers were employed. The first type has symmetric angle blades with identical inlet/outlet angles of ±10°, ±30°, and ±50° and the second group has nonsymmetric angle blades in which the inlet angle was set to 0° and six different angles of ±10°, ±30°, and ±50° were designed for the outlet of the blades. A total of 12 impellers, as well as primary radial blades impeller, were investigated in this study. The results showed that all forward blades have higher head coefficients than radial blades impeller at design flow coefficient. It was found that regenerative pumps with symmetric angle forward blades have better performance than other types. Also, it is worth mentioning that the highest head coefficient and efficiency occur at angle+10<β<+30of symmetric angle blades. It was found that the maximum efficiency occurs at angle of +15.5° by curve fitting to the data obtained from numerical simulations for symmetric angle forward blades.
5
Saowalak Thongdee, Churat Tararuk, Natthawud Dussadee, Rameshprabu Ramaraj i Tanate Chaichana. "Study on performance of a savonius wind turbines related with the blade angle". Maejo International Journal of Energy and Environmental Communication 1, nr 2 (9.08.2019): 32–36. http://dx.doi.org/10.54279/mijeec.v1i2.244916.
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This research aimed to compare the performance of Savonius vertical axis wind turbines through blade numbers and different blade angles. In this study, applicable turbines having 4, 6, 8, 12, 16 and 18 numbers of blades with the angles of the blades of -15°, -5°, 0°, 5° and 15°, respectively. The rotor used was a semicircle shaped blade made from PVC material and has a blade diameter of 6 cm and 30 cm for both rotor diameter and height. The turbine was tested deadweight range of 0-0.49 kg at 4 m/s wind speed. The results showed that the blade angle has a positive effect on increasing the power and torque coefficient of Savonius wind turbine, specifically on blades less than 16. The highest power and torque coefficient was obtained from the turbine having16 blades at an angle of 5°. This configuration also found that the maximum power and torque coefficient in the tip speed ratio ranging from 0.3-0.4 are 0.2519 and 0.5858, respectively.
6
Islamova, O. V., A. Z. Tokov i F. A. Ataeva. "Energy efficiency is the most important indicator of the quality of food grinders". Proceedings of the Voronezh State University of Engineering Technologies 81, nr 2 (1.11.2019): 56–62. http://dx.doi.org/10.20914/2310-1202-2019-2-56-62.
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A brief analysis of the methods of grinding technological raw materials from the standpoint of energy efficiency has been performed. Studies show that cutting (grinding) the feedstock into pieces of a certain size is the most energy-intensive. Existing designs of cutting elements of grinding mechanisms (cutting blade, cutting edge) are not optimal from the standpoint of energy efficiency. For example, the cutting blade in the working hole has a taper angle of 90°, and the taper angle of the cutting blade on the blades of the movable knife is also in the range of 80–90°. It is proposed to make the sharpening angles of the cutting blades on the blades of a movable knife equal to 5–8°. In addition, the blades of such a knife should have the shape of a classic wedge in all cross sections. Reducing the angle of sharpening of the cutting blade in the working hole of the grill to such values does not succeed in terms of design features (in particular, without violating transparency indicators). The reserves of reducing the angle of sharpening of the cutting blade in the working hole are shown (this angle can be less than 90°). The performed studies indicate that the smaller the energy costs for grinding the feedstock, the less it is rubbed and squeezed out of the holes of the grate. It can be assumed that the organoleptic properties did not deteriorate after grinding (but remained). The lower the transparency of the lattice, the grinding process is more energy-consuming. The smaller the sharpening angles of the cutting blades of the knives, the more energy-efficient the grinding process. The worse the quality of the crushed raw materials, for example, meat, which is characterized by the excessive presence of connective and cartilage tissues, films, etc., the more energy-efficient is the grinding process with knives with cutting blades with minimal sharpening angles.
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Nugroho, Arif Setyo, Y. Yulianto Kristiawan i Aris Teguh Rahayu. "Pengaruh Angle Attack Terhadap Luaran Generator Turbin Tipe Darrieus". AEEJ : Journal of Automotive Engineering and Vocational Education 4, nr 1 (10.04.2023): 1–8. http://dx.doi.org/10.24036/aeej.v4i1.162.
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The angle and number of wind turbine blades. The turbine used for testing is a vertical Darrieus-H type turbine with variations in the number of blades 2, 3, and 4. Blades with NACA 4415 specifications, wind speeds with variations of 4 m/s, 5 m/s, 6 m/s, 7 m/s s, and 8 m/s. The source of the wind using a fan. Variations in the angle of attack are 0o, 10o, 20o, and 30o. The blade is made of sea sengon wood. At the position of the angle of attack, 10o rotates faster due to the influence of the lifting force of the blades. The position of the blade angle of attack 0o is difficult to rotate because the blade position is straight with the wind direction. The position of the angle of attack 20o and 30o blades is difficult to rotate because the lifting force of the blades is too heavy compared to the position of the angle of attack 10o. The highest electric power is obtained from the number of blades with 2 angles of attack 10o with a power of 10.5 watts.
Penelitian ini bertujuan untuk mengetahui daya yang dihasilkan akibat pengaruh sudut dan jumlah blade turbin angin. Turbin yang digunakan pengujian adalah turbin vertikal tipe Darrieus -H dengan variasi jumlah sudu 2, 3, dan 4. Blade dengan spesifikasi NACA 4415, kecepatan angin dengan variasi 4 m/s, 5 m/s, 6 m/s , 7 m/s, dan 8 m/s. Sumber angin menggunakan kipas angin. Variasi sudut serang adalah 0o, 10o, 20o, dan 30o. Blade terbuat dari bahan kayu sengon laut. Pada posisi sudut serang 10o berputar lebih cepat karena pengaruh gaya angkat sudu. Posisi sudu sudut serang 0o sulit untuk diputar karena posisi sudu lurus dengan arah angin. Posisi sudut serang 20o dan 30o sudu sulit untuk diputar karena gaya angkat sudu terlalu berat dibandingkan dengan posisi sudut serang 10o. Daya listrik tertinggi diperoleh dari jumlah sudu dengan 2 sudut serang 10o dengan daya 10,5 watt.
8
Santoso, Budi, Dominicus Danardono Dwi Prija Tjahjana i Purwadi Joko Widodo. "Performance Evaluation of Axial Flow Wind Turbine Integrated with The Condenser". Journal of Advanced Research in Fluid Mechanics and Thermal Sciences 76, nr 3 (29.10.2020): 85–91. http://dx.doi.org/10.37934/arfmts.76.3.8591.
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This study investigated the application of an axial flow wind turbine integrated with a condenser. The exhaust air from condenser was used to drive the wind turbine by a ducted turbine system. There were two parameters varied in this work: the blade number and the blade pitch angle. The blade number used was two blades, five blades, and ten blades, while the blade pitch angles were 5°, 10°, 15°, 20°, 30°, and 45°. The diameter of the wind turbine was 495 mm. The model of the condenser had a fan diameter of 600 mm and the range of the average air velocity of 2.01 m/s - 7.86 m/s. The maximum mechanical power was 10.72 W for air velocity of 7.86 m/s. The maximum power coefficient recorded was 0.38 for the tip speed ratio of 1.3 on the blade number of five blades and a pitch angle of 10°. The maximum exhaust air energy recovery was 13.64% of the power consumption of the condenser fan.
9
Tleubergenova, A. Zh, N. K. Tanasheva, K. M. Shaimerdenova, N. K. Botpaev, S. B. Kassiyev i L. L. Minkov. "Investigation of Aerodynamic Characteristics of a Two-Bladed Sailing Wind Turbine". Bulletin of the Karaganda University. "Physics" Series 109, nr 2 (30.03.2023): 42–48. http://dx.doi.org/10.31489/2023ph1/42-48.
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The article examines a prototype of a wind turbine with two blades. For experimental work, a mock-up of a sailing wind turbine consisting of two blades was developed. The material of the sail blades was selected according to elasticity and lightness, cheapness, roughness of the streamlined surfaces. The study shows the aerodynamic parameters acting on the blade. The air flow velocity varied from 3 to 12 m/s. The dependence of the lifting force and the frontal barrier on the air flow velocity was obtained by turning the blades of the wind turbine so that the angle of attack was α = 00, 150, 300, 450, 600. It is established that when the position of the blade’s changes, the lifting force and the drag force decrease. With an increase in the angle of attack α > 00 leads to a decrease in the midsection of the wind wheel with respect to the air flow. On this basis, there is a decrease in aerodynamic forces. As the speed of the air treacle increases, the speed of rotation of the wind wheel also increases. However, during the experiment it was found that the location of the blades at different angles affects the numerical value of the rotational speed. According to the conducted experiments, several values were obtained. The analysis of the obtained values is carried out. A graph is constructed based on the dependence of the wind wheel rotation frequency on the wind speed with a change in the angle of attack. A wind turbine with blades with a variable angle of attack, which, turning, gradually become more parallel to the direction of the wind. Centrifugal forces regulate the inclination of the blades, and as a result, the speed of rotation of the wind wheel, and keep the wind generator at the nominal speed of rotation.
10
Sasongko, Herman, Heru Mirmanto, Galih Bangga, Elita Fidiya Nugrahani i Johan Nicholas Pasaribu. "NUMERICAL APPROACH OF THE BLADE SHAPE AND NUMBER ON THE PERFORMANCE OF MULTIPLE BLADE CLOSED TYPE IMPULSE WIND TURBINE". International Journal of Mechanical Engineering Technologies and Applications 4, nr 2 (30.06.2023): 220–35. http://dx.doi.org/10.21776/mechta.2023.004.02.11.
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An impulse turbine uses drag force on its blades to produce torque on its rotor. As fluid flows over the blades, pressure changes occur at the nozzle, which increases the fluid's velocity and reduces the static pressure at the nozzle outlet. The high-momentum fluid then impinges on the rotor blades, generating frictional force and resulting in torque production. To study the impact of blade shape and number on the turbine's performance, simulations were conducted. The results indicate that blades with an angle of 0° and 180° are optimal for creating high-pressure vortices on the concave surface of the blade. Addition-ally, more blades always result in higher torque and power out-put by increasing the active area of the blades. However, in the case of blades with an angle of 0° and 180°, 8 blades produced more torque than 12 blades with an angle of 0° and 90°. There-fore, blades with an angle of 0° and 180° are highly effective at generating drag force and producing torque.
11
Li, Bei, De Tian, Xiaoxuan Wu, Huiwen Meng i Yi Su. "The Impact of Bend–Twist Coupling on Structural Characteristics and Flutter Limit of Ultra-Long Flexible Wind Turbine Composite Blades". Energies 16, nr 15 (6.08.2023): 5829. http://dx.doi.org/10.3390/en16155829.
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Flutter is an instability phenomenon that can occur in wind turbine blades due to fluid–structure interaction, particularly for longer and more flexible blades. Aeroelastic tailoring through bend–twist coupling is an effective method to enhance the aeroelastic performance of blades. In this study, we investigate the impact of bend–twist coupling on the structural performance and flutter limit of the IEA 15 MW blade, which is currently the longest reference wind turbine blade, and determine the optimal layup configuration that maximizes the flutter speed. The blade is modeled by NuMAD and iVABS, and the cross-section properties are obtained by PreComb and VABS. The accuracy of the blade model is verified in terms of stiffness and frequency. The bend–twist coupling is implemented by changing the fiber angle of the skin and spar cap considering symmetric and asymmetric layups. The flutter limits of both the baseline and the bend–twist coupled blade are evaluated based on HAWC2. The results show that the angle of spar cap carbon fiber has a greater effect on the blade’s structural properties and flutter speed than the skin fiber. Varying the spar cap carbon fiber angle increases the flutter speed, with the effect being more significant for the symmetric layup, up to 9.66% at a fiber angle of 25 degrees. In contrast, the variation in skin fiber angle has a relatively small impact on flutter speed—within ±3%.
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Imam Syofii, Dewi Puspita Sari, Mochamad Amri Santosa, Suproyadi, Anthony Costa, Dendy Adanta, Rudi Darussalam, Andri Setiawan, Arifin Santosa i Kusnadi. "Feasibility of Pico Scale Turgo Turbine Blade Manufacturing Method Using Three-Dimension Printer Technology". Journal of Advanced Research in Fluid Mechanics and Thermal Sciences 107, nr 1 (31.07.2023): 190–201. http://dx.doi.org/10.37934/arfmts.107.1.190201.
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This study proposed the design of pico-scale Turgo turbine blades using triangle velocity and printing blades using three-dimensional (3D) printer technology. Then, describe the testing method of Pico scale Turgo turbines in laboratory conditions. The velocity triangle analysis accommodates backflow where it is affected by blade angle; this is relevant to the Turgo turbine because the flow and blades have an angle so that the estimated change in momentum approaches real conditions. Based on calculation results, the geometry of the pico-scale Turgo turbine blades that produce maximum performance is as follows: angle of attack is 20°, inlet blade angle is 40°, outlet blade angle is 10°, and radius blade angle is 15°. Then, simulation results determine the potential water power that the blade is capable of receiving is 17.5 W. The experimental setup has a potential water power of 14.81 W, lower than the mechanical strength simulation results. From the experimental results, the performance maximum is 0.092; the average deviation between the analytical and experimental is 4%. Therefore, the manufacture of pico-scale Turgo turbine blades using 3D printer technology is considered because of the ease of the manufacturing process, the time needed in the manufacturing process is short, and the cost is low.
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Wu, Kuo-Tsai, Kuo-Hao Lo, Ruey-Chy Kao i Sheng-Jye Hwang. "Numerical and Experimental Investigation of the Effect of Design Parameters on Savonius-Type Hydrokinetic Turbine Performance". Energies 15, nr 5 (2.03.2022): 1856. http://dx.doi.org/10.3390/en15051856.
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To meet the increased demand of hydroelectric power generation, a novel drag-based Savonius turbine with the characteristics of a simpler fabrication process and good starting characteristics is designed, fabricated, and analyzed. The newly designed turbine is suitable to be installed in rivers, irrigation channels, ocean currents, etc., for small-scale hydroelectric power generation. In the present study, experiments are carried out to investigate the influence of the design parameters of this turbine on its power performance in order to improve its efficiency, including blade arc angles (180°, 135°), blade placement angles (0°, ±22.5°), and the number of blades (2, 3, 6, and 8). Further, three-dimensional CFD simulations are performed with Re = 6.72×105, matching the experimental conditions, in order to study the changes in the flow field and the rotation characteristics of the turbine. The research results indicate that a six-bladed turbine with a blade arc angle of 135° and a blade placement angle of 0° has higher torque and better power performance, which makes it the most suitable design when also considering cost. Furthermore, it was found that an increase in the number of turbine blades contributes to improving the performance of the turbine. The maximum power coefficient is 0.099 at a tip speed ratio of 0.34.
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Zhang, Hong-li, Fan-yu Kong, Ai-xia Zhu, Fei Zhao i Zhen-fa Xu. "Effect of Blade Outlet Angle on Radial Force of Marine Magnetic Drive Pump". Shock and Vibration 2020 (11.09.2020): 1–18. http://dx.doi.org/10.1155/2020/8827333.
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To research the effects of the blade outlet angle on the performance and the radial force of the marine pump, the unsteady numerical simulation of the four different models is carried out. The radial forces on the impeller and the blades are obtained under different flow rate conditions. The time and frequency domain characteristics of radial resultant force on the impeller and the blades are analyzed and those of the impeller torque are researched. The results show that the radial forces of the impeller and the blades increase with the increase of the blade outlet angle at the same flow rate. With the same blade outlet angle, the radial forces decrease with the increase of the flow rate. The roundness of radial force vector diagram becomes more obvious with the decrease of the blade outlet angle. The root mean square (RMS) of radial force on the blades is about 30% of that on the impeller. The main frequency of radial force on the impeller and the blades is the axial passing frequency (APF), and that of impeller torque is the blade passing frequency (BPF), and there are peaks at the blade frequency multiplier. At the same flow rate, the main frequency and maximum fluctuation amplitudes on the impeller and the blades increase with the increase of the blade outlet angle. Meanwhile, the impeller torque increases with the increase of the blade outlet angle. With the same blade outlet angle, the main frequency, maximum fluctuation amplitudes, and the impeller torque decrease with the increase of the flow rate. The amplitude difference decreases with the increase of the flow rate. The blade outlet angle has an obvious greater influence on the radial forces and fluctuation at the small flow rate. The vibration test shows that the vibration intensities of model 25 and model 35 are less than 2.5 mm/s, and the vibration intensity of model 25 is about 0.2 mm/s less than that of model 35.
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Hikmat, Yusiran, i Erwin Erwin. "STUDI EKSPERIMEN TEKNOLOGI PEMBANGKIT LISTRIK TENAGA ARUS LAUT (PLTAL) MENGGUNAKAN SAVONIUS BACH ROTOR". Komunikasi Fisika Indonesia 16, nr 2 (31.10.2019): 75. http://dx.doi.org/10.31258/jkfi.16.2.75-80.
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Design and experiment of ocean current power generation system have been carried out using the Bach Savonius rotor. In this research, the influence of the velocity of ocean currents, the number of turbine blades, and the blade arc angle of the generator output power are studied. The results showed that the turbine output power is strongly influenced by the velocity of ocean currents where the velocity values of ocean currents varied in the range 0,63-1,98 m/sec. The maximum elctrical power of the turbine occurs at a current velocity of 1,98 m/sec of 26,88 Watts. The number of turbine blades has a significant effect on turbine output power. The turbine reaches maximum power is found in the rotor with a number of 3 blades with a power coefficient of 0,1176 on the tip speed ratio of 0,359. The blade arc angle is varied at angles of 90˚, 135˚ and 165˚. The blade arc angle 135˚ gives the best performance with a power coefficient of 0,102 on the tip speed ratio of 0,298.
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Susilo, Sugeng Hadi, i Agus Setiawan. "Analysis of the number and angle of the impeller blade to the performance of centrifugal pump". EUREKA: Physics and Engineering, nr 5 (13.09.2021): 62–68. http://dx.doi.org/10.21303/2461-4262.2021.002001.
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The paper discusses the performance of the pump in relation to the impeller. The impeller section is determined by the number and angle of the blades. Therefore, the purpose of this study was to analyze the role of the number and angle of impeller blades on the performance (discharge and discharge pressure) of centrifugal pumps based on experiments and simulations.
The method used is experiment and simulation. Using a centrifugal pump type GWP 20/4 SW, Maximum Output: 6.5 HP/3500 rpm, Inlet/Outlet: 2 Inch, Dimensions: 475x375x370 mm. Experiments and simulations by varying the number of blades 2, 4, and 6 with a blade tilt angle of 130°, 150°, and 160°. For flow simulation using solid works program.
The results show that pump performance is related to discharge pressure, impeller with 2-blades and an angle of 130° the pressure increases 0.45–2.45 bar, for 150° increases 0.14–2.96 bar, and 160° increases 0.29–3.07 bars. For a 4-blade impeller and an angle of 130°, the pressure increases by 0.48–3.12 bar, for 150° it increases by 0.39–3.39 bar, and for 160° it increases by 0.36–3.48 bar. While the impeller for 6-blades with an angle of 130° the pressure increases from 0.6 bar to 3.72 bar, for 150° increases from 1.36 to 4.34 bar, and 160° increases by 0.36–4.74 bar. While it related pump performance to flow rate, increasing the number of blades causes a decrease in flow rate. The highest flow rate is in a 2-blade impeller with a blade angle of 130° is 404.91 l/s. The lowest flow rate is on a 6-blade impeller with an angle of 160° is 279.66 l/s
17
Ye, Dechao, Fajie Duan, Jiajia Jiang, Guangyue Niu, Zhibo Liu i Fangyi Li. "Identification of Vibration Events in Rotating Blades Using a Fiber Optical Tip Timing Sensor". Sensors 19, nr 7 (27.03.2019): 1482. http://dx.doi.org/10.3390/s19071482.
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The blade tip timing (BTT) technique has been widely used in rotation machinery for non-contact blade vibration measurements. As BTT data is under-sampled, it requires complicated algorithms to reconstruct vibration parameters. Before reconstructing the vibration parameters, the right data segment should first be extracted from the massive volumes of BTT data that include noise from blade vibration events. This step requires manual intervention, is highly dependent on the skill of the operator, and has also made it difficult to automate BTT technique applications. This article proposes an included angle distribution (IAD) correlation method between adjacent revolutions to identify blade vibration events automatically in real time. All included angles of the rotor between any two adjacent blades were accurately detected by only one fiber optical tip timing sensor. Three formulas for calculating IAD correlation were then proposed to identify three types of blade vibration events: the blades’ overall vibrations, vibration of the adjacent two blades, and vibration of a specific blade. Further, the IAD correlation method was optimized in the calculating process to reduce computation load when identifying every blade’s vibration events. The presented IAD correlation method could be used for embedded, real-time, and automatic processing applications. Experimental results showed that the proposed method could identify all vibration events in rotating blades, even small events which may be wrongly identified by skillful operators.
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Pribadyo, Pribadyo, Hadiyanto H i Jamari J. "Simulasi Performa Turbin Propeller Dengan Sudut Pitch Yang Divariasikan". Jurnal Mekanova: Mekanikal, Inovasi dan Teknologi 6, nr 1 (11.06.2020): 54. http://dx.doi.org/10.35308/jmkn.v6i1.2257.
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Propeller turbine performance can be improved by changing the turbine design parameters. One method that was developed is to vary the blade angle on the runner's blades. Analysis of the influence of blade angle on propeller turbine performance is done through numerical simulations based on computational fluid dynamics. The simulation is done with variations of propeller turbine blade angles of 180, 230, and 280 at flow rates of 0.08 m/s to 0.5 m/s. Simulation results show turbines with 250 blade angles have the best performance compared to turbine blade angles of 230 and 280. While the turbine blade angles of 230 tend to have higher performance compared to angles of 280 even though both have peak values for the corresponding power coefficient. Keywords—Propeller turbine, runner blade, pitch angle, CFD simulation
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Maher Labib, Andrew, Ahmed Farouk Abdel Gawad i Mofreh Melad Nasseif. "Effect of Blade Angle on Aerodynamic Performance of Archimedes Spiral Wind Turbine". Journal of Advanced Research in Fluid Mechanics and Thermal Sciences 78, nr 1 (1.12.2020): 122–36. http://dx.doi.org/10.37934/arfmts.78.1.122136.
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Energy harvesting from wind in urban areas is an important solution to meet energy needs and environmental care. This study describes the effect of blade angle on the aerodynamic performance of small-scale Archimedes spiral-wind-turbine blades by computational simulation, which is experimentally validated. Archimedes wind turbine is classified as one of the HAWTs. The computational approach was used to predict the aerodynamic performance of the scaled-down rotor blades. Blade angle is defined by the angle between the rotational axis and the tip of the blade, which varied from 50° to 65° with an interval of 5°. The computational study was carried out using the ANSYS CFX 19 software for a steady incompressible flow. The performance parameters of the wind turbine, which are power and torque coefficients were explored for different blade angles. This was carried out for wind speed from 5 to 12 m/s with an interval of 1 m/s. In order to validate the results of the computational simulation, an experimental study was carried out using a scaled-down 3D-printed models. The experimental study concentrated on the effect of blade angle on the rotating speed for the different turbine models. Obviously, the results highlight that the maximum power coefficient has an inverse relation to the blade angle.
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Amiruddin, Hilmi, Wan Mohd Faizal Wan Mahmood, Shahrir Abdullah, Mohd Radzi Abu Mansor, Rizalman Mamat i Azri Alias. "Application of Taguchi method in optimization of design parameter for turbocharger vaned diffuser". Industrial Lubrication and Tribology 69, nr 3 (8.05.2017): 409–13. http://dx.doi.org/10.1108/ilt-09-2016-0224.
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Purpose The purpose of this study is to determine the best vaned diffuser design that can generate higher pressure output at a predetermined speed. Design/methodology/approach Several vaned diffusers of thin, flat-type design with different number of blades and blade angle were fabricated. The vaned diffusers were fitted inside the turbocharger compressor and test on a cold-flow turbocharger test rig. A Taguchi L27 orthogonal array is selected for analysis of the data. Influence of number of blades, blade angle and rotational speed on output pressure is studied using the analysis of variance (ANOVA) technique. Finally, confirmation tests are conducted to validate the experimental results. Findings The optimum design parameters of the vaned diffuser using signal-to-noise ratio analysis were six blades type, blade angle of 18° and rotational speed of 70,000 rpm. Results from ANOVA showed that the speed has the highest influence on output pressure. The number of blades and blade angle produced the least effect on the pressure output. Originality/value The study used the turbocharger with the impeller size 60 mm and adapted vaned diffuser to increase the output pressure.
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Purwoko, Purwoko. "PENGARUH JUMLAH DAN SUDUT PEMASANGAN SUDU TERHADAP DAYA TURBIN SAVONIUS". INFO-TEKNIK 21, nr 2 (25.01.2021): 125. http://dx.doi.org/10.20527/infotek.v21i2.10036.
Pełny tekst źródłaStreszczenie:
The problem in Energy conservation is finding new opportunities for high-efficiency energy generation including wind power generating machines. Aims of this study to determine the effects of blade number and curv angle of blade mounting on the output power of a Savonius type wind turbine. This low speed wind turbine is intended to get energy at the top of a multi-storey building in an urban area. Tests were carried out on a laboratory scale, using savonius wind turbines with 400 mm diameter and 500 mm height. The driving wind speed of the turbine is set between 1.5 to 8.5 m / s. While the number of blades used is 2 types, namely rotor with three blades and rotor with 4 blades, each of which is tested on 3 different types of curv angle blade.
The investigation results are expected to show that the wind tubing from each experiment will give different characteristics. This investigation results that there was increasing in efficiency in the savonius turbine with blades. The highest rotation and power occur when the turbine uses 2 blades and -50 curv angle of blade mounting
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Ni, Shaosong, Wenbin Cao, Jun Xu, Yingdong Wang i Wei Zhang. "Effects of an Inclined Blade on the Performance of a Sirocco Fan". Applied Sciences 9, nr 15 (2.08.2019): 3154. http://dx.doi.org/10.3390/app9153154.
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The impeller is the primary working component of centrifugal fans, whose internal flow directly determines the performance of the whole system. This work presents a numerical investigation by using ANSYS-Fluent on the internal flow of a Sirocco fan to investigate the effects of the inclination angle of the blades on the fan performance. The orientation of the blade for the baseline model is strictly along the axial direction, while three inclination angles, i.e., 3.5°, 7.0°, and 10.5°, are chosen for the inclined blades of the modified impeller to improve the aerodynamic performance of the fan. The effects of the inclined blade are demonstrated by the variations in static pressure, efficiency, and pressure and velocity distributions at various inclination angles. The computed results reveal that there is an optimum inclination angle, which produces the best aerodynamic performance.
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Nejad, J., A. Riasi i A. Nourbakhsh. "Efficiency improvement of regenerative pump using blade profile modification: Experimental study". Proceedings of the Institution of Mechanical Engineers, Part E: Journal of Process Mechanical Engineering 233, nr 3 (22.03.2018): 448–55. http://dx.doi.org/10.1177/0954408918763554.
Pełny tekst źródłaStreszczenie:
Regenerative flow pump is a kind of turbomachine with the ability to generate high heads at relatively low flow rates. Despite having low hydraulic efficiency, regenerative pumps have found many applications in industries due to their simplicity, compact size, low manufacturing costs, and low specific speed. In this paper, an experimental study has been carried out to investigate the influence of impeller blade change on the performance of regenerative pump. To this end, the straight radial blades were changed to curved blades with the same inlet/outlet angles. Three forward curved blade impellers as well as straight radial blade impeller were designed and manufactured. Since the regenerative pump comply with the affinity laws, the results of experimental tests were expressed in nondimensional coefficients. The results showed that by increasing the blade angle to 10°, the efficiency increased and at higher blade angles of 30° and 50°, the efficiency decreased for all flow conditions. The best angle was obtained about 15° by curve fitting to the experimental data at the design flow coefficient.
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Purwoko, Santoso i Nurchajat. "PENGARUH JUMLAH DAN SUDUT PEMASANGAN SUDU TERHADAP DAYA TURBIN ANGIN SAVONIUS". Jurnal Teknik Ilmu Dan Aplikasi 9, nr 2 (28.04.2021): 17–21. http://dx.doi.org/10.33795/jtia.v9i2.27.
Pełny tekst źródłaStreszczenie:
The problem in Energy conservation is finding new opportunities for high-efficiency energy generation including wind power generating machines. This study aims to determine the effect of the number and curv angle of blade mounting on the output power of a Savonius type wind turbine. This low speed wind turbine is intended to get energy at the top of a multi-storey building in an urban area. Tests were carried out on a laboratory scale, using savonius wind turbines with a diameter of 400 mm and a height of 500 mm. The driving wind speed of the turbine is set between 1.5 to 8.5 m / s. While the number of blades used is 2 types, namely rotor with three blades and rotor with 4 blades, each of which is tested on 3 different types of curv angle blade. The investigation results are expected to show that the wind tubing from each experiment will give different characteristics. The results showed that there was an increase in efficiency in the savonius turbine with blades. The highest rotation and power occur when the turbine uses 2 blades and -50 curv angle of blade mounting
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Syuriadi, Adi, Ahmad Indra Siswantara, Dewin Purnama, Gun Gun Ramdlan Gunadi, Iwan Susanto i Sulaksana Permana. "Identifying the influence of blade number and angle of attack on a breastshot type waterwheel micro hydroelectric power generator using ANOVA". Eastern-European Journal of Enterprise Technologies 4, nr 8 (124) (31.08.2023): 26–31. http://dx.doi.org/10.15587/1729-4061.2023.286040.
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This study focuses on optimizing the performance of micro-hydro power generation, specifically the breastshot type waterwheel. The limited availability of non-renewable energy sources and the high cost of developing renewable energy sources in the energy sector pose challenges, making it essential to find new energy sources and improve energy efficiency. The 2004–2022 national electricity plan aims to increase electricity access in rural areas, including remote regions like Bogor Regency, where access to electricity is limited. Many residents have constructed their own micro hydroelectric power generators, but their vulnerability to natural disasters is a concern. The study investigates the potential of breastshot waterwheel technology for micro hydroelectric power generation. The study involved testing a micro hydro power plant with 6, 8, and 10 blades and blade angles of 0°, 30°, and 45°. The current research focuses on performance optimization, including the use of ANOVA analysis to know the significant impact of blade number and angle on the waterwheel’s rotation. The maximum rotational speed was achieved with 10 blades and an angle of attack of 0°, 30°, and 45°, with respective speeds of 153.59 RPM, 155.84 RPM, and 164.95 RPM. The study indicates that the higher the number and angle of attack of blades, the greater the rotation of the breastshot type waterwheel. ANOVA tests showed that the number of blades had a significant impact on the waterwheel’s rotation, with an F-test value of 6.32 and a p-value of 0.012. On the other hand, the angle of attack of the blade had no significant impact, with an F-test value of 3.20 and a p-value of 0.067
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Wang, Shi Ming, i Ka Tian. "Flow Field Numerical Simulation Analysis of Five Wing Horizontal Wave Turbine Power Plant with Different Blade Angles". Applied Mechanics and Materials 477-478 (grudzień 2013): 221–25. http://dx.doi.org/10.4028/www.scientific.net/amm.477-478.221.
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Used FLUENT software to simulate the flow distribution of a certain horizontal turbine with its blade angle changed from 25 ° to-35 °.The simulation results show the flow field changes with a period which was a fifth to the turbine rotational period. When the blade heads deflected laterally, the high flow velocity appeared near rear back turbine blades, or it appeared near the facing flow blades which were in the front lower part of the turbine. Besides, for blade angle deflected inside models, a stable annular velocity vector vortex gradually emerged around turbine as blade angle increased. The maximum velocity of flow field increased firstly and then stayed stable as blade angle changed. The flow distribution results fully confirmed that the reasonable optimization to the blade angle of the turbine can help the turbine achieve a more effective rotation and improve the flow distribution.
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Shah, Imran, Abdullah Khan, Muhsin Ali, Sana Shahab, Shahid Aziz, Muhammad Adnan Aslam Noon i Javed Ahmad Khan Tipu. "Numerical and Experimental Analysis of Horizontal-Axis Wind Turbine Blade Fatigue Life". Materials 16, nr 13 (3.07.2023): 4804. http://dx.doi.org/10.3390/ma16134804.
Pełny tekst źródłaStreszczenie:
Horizontal-axis wind turbines are the most popular wind machines in operation today. These turbines employ aerodynamic blades that may be oriented either upward or downward. HAWTs are the most common non-conventional source of energy generation. These turbine blades fail mostly due to fatigue, as a large centrifugal force acts on them at high rotational speeds. This study aims to increase a turbine’s service life by improving the turbine blades’ fatigue life. Predicting the fatigue life and the design of the turbine blade considers the maximum wind speed range. SolidWorks, a CAD program, is used to create a wind turbine blade utilizing NACA profile S814. The wind turbine blade’s fatigue life is calculated using Morrow’s equation. A turbine blade will eventually wear out due to several forces operating on it. Ansys software is used to analyze these stresses using the finite element method. The fatigue study of wind turbine blades is described in this research paper. To increase a turbine blade’s fatigue life, this research study focuses on design optimization. Based on the foregoing characteristics, an improved turbine blade design with a longer fatigue life than the original one is intended in this study. The primary fatigue parameters are the length of a chord twist angle and blade length. The experimental data computed with the aid of a fatigue testing machine are also used to validate the numerical results, and it is found that they are very similar to one another. By creating the most effective turbine blades with the longest fatigue life, this research study can be developed further. The most effective turbine blades with the longest fatigue life can be designed to further this research investigation.
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Szczerba, Zygmunt, Piotr Szczerba, Kamil Szczerba, Marek Szumski i Krzysztof Pytel. "Wind Tunnel Experimental Study on the Efficiency of Vertical-Axis Wind Turbines via Analysis of Blade Pitch Angle Influence". Energies 16, nr 13 (23.06.2023): 4903. http://dx.doi.org/10.3390/en16134903.
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This paper presents results of experimental investigations and numerical simulations of a vertical-axis H-type wind turbine, considering the influence of propeller blade pitch angle on turbine characteristics. An innovative airfoil profile based on a modified symmetric NACA0015 airfoil profile was used as the designed blade profile, which was tested in a wind tunnel over a range of Reynolds numbers from 50,000 to 300,000. The phenomenon of angle-of-attack variation and the resulting forces acting on the blades, particularly in the horizontal configuration and vertical axis of rotation, were discussed. Series of experiments were conducted on a 1:1 scale four-bladed turbine model in the wind tunnel to determine the characteristics, specifically the power coefficient distribution over the tip speed ratio for various Reynolds numbers and blade pitch angles. Subsequently, the turbine was modeled using Qblade software, and a series of calculations were performed under the same conditions. The numerical results were validated with the experimental data.
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Masykur, Masykur, Andre Kurniadi, Maidi Saputra i Murhaban Murhaban. "Studi Numerik Pengaruh Sudut Kemiringan Sudu Terhadap Performa Turbin Angin Vertikal Tipe Savonius". Jurnal Mekanova: Mekanikal, Inovasi dan Teknologi 7, nr 1 (4.06.2021): 25. http://dx.doi.org/10.35308/jmkn.v7i1.3634.
Pełny tekst źródłaStreszczenie:
AbstractWind energy is a renewable energy source that can be felt in everyday life. To convert wind energy into electrical energy, a tool is needed that is a wind turbine. Horizontal Axis Wind Turbine is more widely used and developed today than the vertical type wind turbine. However, the vertical turbine has several advantages compared to the horizontal wind turbine, which is that it can move without depending on the direction of the wind. This study aims to determine the effect of tilt angel of savonius turbine with blades angle 30°, 60° and 90° the turbine power coefficient and determine the optimal turbine blade results in designing a Vertical wind turbine by simulation using Computational Fluid Dynamics (CFD). The variations used are tilt angel turbine blades is 30°, 60°, 90°. The results showed that the value of Cp (Power Coefficient) of wind turbines with the addition of the blade angel 30°, 60° and 90° had a different increase. The variation the addition of turbine blade tilt angle with 90° tilt angle can increase the efficiency of the turbine blade when compared 30°, 60° blade inclination this is evidenced by wind turbine speed contour analysis, wind vortex contour analysis and turbulence intensity contour analysis shows that the turbine blade simulation results with a slope of 90° has an efficient turbine blade that is very good and effective and get optimal results.Keywords: Wind turbine, VAWT, CFD, Efficiency, Contour, Optimal, TSR, power
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Kumar Vandrangi, Seshu. "AERODYNAMIC CHARACTERISTICS OF NACA 0012 AIRFOIL BY CFD ANALYSIS". Journal of Airline Operations and Aviation Management 1, nr 1 (25.07.2022): 1–8. http://dx.doi.org/10.56801/jaoam.v1i1.1.
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The wind turbine's aerodynamic efficiency is heavily influenced by the aerodynamic airfoil blades. It's critical to choose the right aerofoil section for the blade. The angle of attack and its impact on lift and drag forces, such as high lift and low drag or vice versa, are key elements that determine the wind turbine system's efficiency. Using this as inspiration, the NACA 0012 airfoil profile is used to investigate the influence of angle of attack on the aerodynamic performance of wind turbine blades. The airfoil geometry is produced using computational fluid dynamics, according to the National Advisory Committee for Aeronautics (NACA) guidelines. The aerodynamic findings are evaluated in terms of static pressure and velocity distributions, as well as different angles of attack, in this study. The angle of attack increases as the lift/drag ratio decreases, according to the CFD study. Other elements, such as blade backflow turbulence and blade forces, should be addressed when evaluating the aerodynamic performance of NACA aerofoils.
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Zhao, Wenbin, Jianbin Hu i Kai Wang. "Influence of Channel-Diffuser Blades on Energy Performance of a Three-Stage Centrifugal Pump". Symmetry 13, nr 2 (5.02.2021): 277. http://dx.doi.org/10.3390/sym13020277.
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In order to improve hydraulic efficiency, influence of inlet angle, outlet angle, wrap angle, inlet shape and outer edge camber lines of channel-diffuser blades on the energy performance of a three-stage centrifugal pump were studied and the pressure distributions on the blade of the first-stage channel-diffuser were particularly analyzed. The result shows that the efficiency of the pump is maximal when the blade inlet angle is 12°. The pressure variation in the model with the inlet angle of 12° was small and the amplitude of fluctuation was also not large. When the outlet angle was 90°, the pressure distribution in the outlet of the blades that are symmetrically distributed along the center of the diffuser shell was significantly better than that with other outlet angles. The effect of the blade wrap angle of the channel-diffuser on the energy performance of the pump was relatively small. The internal flow in the diffuser with the diffusion inlet shapes was steady for both the convex surface and concave surface. The diffusion inlet of the channel-diffuser blade corresponded to the outlet region of the impeller blade, which reflected a good matching. The fluctuation amplitude and the distribution range of the models with a uniform transition were smaller than those with non-uniform transition. In order to verify the effectiveness of the research results, an experimental test was carried out on the pump. The results show that when the flow rate is 850 m3/h, the head of the pump is 138.67 m and the efficiency of pump is 69.48%.
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Li, Junjie, Yunfeng Lou, Gaoyuan Yu, Tong Li i Xianlong Jin. "Effect of Bird Yaw/Pitch Angles on Soft Impact Damage of a Fan Assembly". Complexity 2021 (16.01.2021): 1–13. http://dx.doi.org/10.1155/2021/8879874.
Pełny tekst źródłaStreszczenie:
This paper presents a numerical investigation of bird attitude angles affecting the soft-impact damage of a full fan assembly. Firstly, considering the geometry of a mallard, a real bird model is established by the Smoothed Particle Hydrodynamics (SPH) method and calibrated with available test data. Then, complying with airworthiness requirements, simulations of a full-bladed fan assembly subjected to a real bird were conducted to determine the critical ingestion parameters (CIP). Furthermore, a real bird with different attitude angles aimed at a full fan assembly was simulated. Results show that attitude angles of the bird produce a significant impact on the effect of the bird strike on rotating blades and would increase the possibility of blade failures, especially for the yaw angle of -45° and the pitch angle of −60°. It is invaluable for commercial airlines and engine manufactures to provide safe flight and landing by adopting the real bird model with critical yaw and pitch angles in the design for resistance to bird ingestion.
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Abood, Yasir A., Waad E. Kasid, Omar Abdulrazzaq i Haider S. Hussein. "Effect of the Blade Pitch on the Performance of Small Wind Turbine Exposed to Wind Stream of Various Angles of Attack". Iraqi Journal of Industrial Research 9, nr 1 (14.06.2022): 31–38. http://dx.doi.org/10.53523/ijoirvol9i1id151.
Pełny tekst źródłaStreszczenie:
In wind turbines, several parameters can affect the productivity of the turbine, such as wind velocity, rotor area, blade aerodynamic design, and blade pitch. In this paper, the effect of various pitch angles for a small wind turbine was investigated. A system of two metal stands with same height is installed (i.e. on the same axis of streaming), the first stand holds an air blower which imitates the wind with constant air blowing. The other, holds a small wind turbine consists of a DC motor and metal hub (steel bush) with 3-blades with equal radial distance (120°). The pitch angle was adjusted at a certain degree of inclination (10°) in which the turbine stars to rotate, then readings of power and rotational speed were collected. The process then repeated with another 3 different angles (15°, 20°, and 25°). At the end, a fixed pitch angle degree was adjusted, and then the lowest and highest air velocity that affecting the blades rotation were measured.
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Rubinstein, R. "STAEBL/General Composites With Hygrothermal Effects (STAEBL/GENCOM)". Journal of Engineering for Gas Turbines and Power 110, nr 2 (1.04.1988): 301–5. http://dx.doi.org/10.1115/1.3240121.
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A computer code has been developed to perform structural optimization of turbine blades made from angle ply fiber composite laminates. Design variables available for optimization include geometric parameters such as blade thickness distribution and root chord, and composite material parameters such as ply angles and numbers of plies of each constituent material. Design constraints include resonance margins, forced response margins, maximum stress, and maximum ply combined stress. A general description of this code is given. Design optimization studies for typical blades are presented.
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Wang, Yong, De Tian i Wei He. "Computation of Hoisting Forces on Wind Turbine Blades Using Computation Fluid Dynamics". Applied Mechanics and Materials 446-447 (listopad 2013): 452–57. http://dx.doi.org/10.4028/www.scientific.net/amm.446-447.452.
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The hoisting forces on a 38.5m wind turbine blade in multiple positions are computed using the computational fluid dynamics (CFD) method. The computation model is constructed with the steady wind conditions, blade mesh model and the blade positions which are determined by the blade pitch angle, azimuth angle and rotor yaw angle. The maximal and minimal hoisting forces in three-dimensional coordinates are found and the corresponding pitch angle, azimuth angle and yaw angle are obtained. The change of the hoisting forces on wind turbine blades is analyzed. Suggestions are given to decrease the hoisting forces of the blade in open wind environment.
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HUYNH, THANH NGOC, TOẢN QUỐC TRẦN i QUYẾT THÀNH PHẠM. "Research on aerodynamic characteristics through airflow clearances in compressor blades of gas turbine engine". Science & Technology Development Journal - Engineering and Technology 3, SI3 (27.12.2020): first. http://dx.doi.org/10.32508/stdjet.v3isi3.640.
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Reducing the loss in the airflow clearance among the compressor blades of the rotor disk and stationary blades (guide vanes) is an urgent issue. Furthermore, additional losses of airflow through the clearances among the blades and airfoil losses are the main cause of reducing the efficiency of an axial flow compressor, especially the blade height is small. With a view towards the efficiency improvement of a multistage axial compressor with a high-pressure ratio, it is necessary to manufacture a highly economical compressor with a variety of compression stages. Airflow in the circulation clearances alternating among compressor blades has viscosity, unstable compression, and quite complex flow structure. This needs to be researched into the design with the assistance of modern software (ANSYS CFX, FlowER, etc.). Although this is an important step in the current design orientation, it requires additional practical elements to perform, especially the problem of optimizing the outer rim, the level, and the number of compression stages in the whole compressor. In this paper, authors have used the method of creating three-dimensional (3D) models for blade profiles in a compressor based on analyzing the flow in three-dimensional form and studying their parameters. This paper deals with the geometry problems of the row of rotating blades (cascade) by proposing the structural arrangement of stacking blades in the circular direction and the blade profile formed the S-shape. Investigating and calculating the aerodynamic properties of the airflow through clearances of compressor blades by using ANSYS is one of the new methods. The researched result showed the dependence between the camber angle as the rotating blade formed an S-shape profile rotates regarding the stagger angle of the airfoil and the incident angle of airflow. Some characteristics of aerodynamic properties are distributed according to the blade height in conducting with different curved profiles of the rotating blades on the rotor disk and stationary blades.
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Khalafallah, Mohamed G., Abdelnaby M. Ahmed i Mohamed K. Emam. "The effect of using winglets to enhance the performance of swept blades of a horizontal axis wind turbine". Advances in Mechanical Engineering 11, nr 9 (wrzesień 2019): 168781401987831. http://dx.doi.org/10.1177/1687814019878312.
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One of the recent methods to improve the performance of horizontal axis wind turbine is to attach a winglet at the tip of the blade of these turbines. Winglets reduce the effect of vortex flow at the blade tip and thus improve the performance of the blade. This article presents a parametric study using the computational fluid dynamics (CFD) modeling to investigate the capability of a winglet to increase the turbine power of swept blades as well as straight blades of a horizontal axis wind turbine. The effects of winglet direction, cant angle, and twist angle are studied for two winglet orientations: upstream and downstream directions. The numerical simulation was performed using ANSYS Fluent computational fluid dynamics code. A three-dimensional computational domain, cylindrical rotationally periodic, was used in the computations. The k-ω shear-stress transport turbulence model was adopted to demonstrate turbulence in the flow. Results show that horizontal axis wind turbine with winglet and sweep could enhance more power compared to their equivalent straight or swept blade. The best improvement in the coefficient of power is 4.39% at design tip speed ratio. This is achieved for downstream swept blades with winglets pointing in the upstream direction and having cant and twist angles of 40° and 10°, respectively.
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Song, Xueyi, Hao Yuan Li, Ying Li i Xianwu Luo. "The development of a high-speed miniature pump with dynamic bearing". Journal of Physics: Conference Series 2217, nr 1 (1.04.2022): 012049. http://dx.doi.org/10.1088/1742-6596/2217/1/012049.
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Abstract A high-speed miniature pump is proposed for the application in aerospace area, where high efficiency and reliability are expected for the pump under the microgravity operation condition. In this paper, a miniature centrifugal pump with dynamic bearing is selected as the objective for the performance development. The prototype of the miniature pump is manufactured and tested by experiments at the rotational speed of 10,000r/min. The comparison of hydraulic performance near the design operation shows good agreement between the numerical results and experimental data. In order to improve hydraulic performance of the pump, the effects of splitter blades, number of blades, and wrap angle of blades are analyzed numerically. For each operating condition, in order to compare the influence of splitter blades on the performance and the internal flow, the impellers with and without splitter blades are designed respectively. In addition, for the splitter blades, the influence of the splitter blade position and the splitter blade thickness are also investigated. The numerical result shows that the highest efficiency among all the impellers is achieved with the blade number of 5, wrap angle of 160° and with no splitter blades. Moreover, for the impellers with the splitter blades, hydraulic performance of the pump is mainly decided by the main blades, while the splitter blades hardly help to improve the efficiency of the pump. The study is helpful for the further application of the high-speed miniature pump in various societies.
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Divakaran, Unnikrishnan, Ajith Ramesh, Akram Mohammad i Ratna Kishore Velamati. "Effect of Helix Angle on the Performance of Helical Vertical Axis Wind Turbine". Energies 14, nr 2 (12.01.2021): 393. http://dx.doi.org/10.3390/en14020393.
Pełny tekst źródłaStreszczenie:
The energy crisis has forced researchers to look for various non-conventional energy sources. Wind energy is one of the potential sources, and researchers have invested resources in developing different kinds of wind turbines. Vertical axis wind turbines (VAWT) have received less attention than their horizontal-axis counterparts. A helical-bladed VAWT is preferred because it makes perfect sense as an improvement in design, as they have higher azimuth angles of power generation capabilities. This paper studies the effects of the helix angle of blades in the aerodynamic performance of VAWT using 3D numerical simulations. Three different helix angles of 60°, 90°, and 120° of a three-bladed VAWT operating across different tip speed ratios were studied. Turbulence is modelled using a four-equation transition SST k-ω model (shear stress transport). The 60° helical-bladed VAWT was found to be better performing in comparison with all other helical-bladed and straight-bladed VAWT. The ripple effects on the shaft are also analysed using a standard deviation plot of the moment coefficient generated by a single blade over one complete cycle of its rotation. It was observed that the greater the helix angle, the lower the standard deviation. The paper also tries to analyse the percentage of power generated by each quartile of flow and the contribution of each section of the blade. Ansys FLUENT was employed for the entire study. A comparative study between different helical-bladed VAWT and straight-bladed VAWT was carried out along with wake structure analysis and flow contours for a better understanding of the flow field.
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Guo, Jia, Timing Qu i Liping Lei. "Effect of Pitch Parameters on Aerodynamic Forces of a Straight-Bladed Vertical Axis Wind Turbine with Inclined Pitch Axes". Applied Sciences 11, nr 3 (24.01.2021): 1033. http://dx.doi.org/10.3390/app11031033.
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Pitch regulation plays a significant role in improving power performance and achieving output control in wind turbines. The present study focuses on a novel, pitch-regulated vertical axis wind turbine (VAWT) with inclined pitch axes. The effect of two pitch parameters (the fold angle and the incline angle) on the instantaneous aerodynamic forces and overall performance of a straight-bladed VAWT under a tip-speed ratio of 4 is investigated using an actuator line model, achieved in ANSYS Fluent software and validated by previous experimental results. The results demonstrate that the fold angle has an apparent influence on the angles of attack and forces of the blades, as well as the power output of the wind turbine. It is helpful to further study the dynamic pitch regulation and adaptable passive pitch regulation of VAWTs. Incline angles away from 90° lead to the asymmetric distribution of aerodynamic forces along the blade span, which results in an expected reduction of loads on the main shaft and the tower of VAWTs.
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Molatudi, Errol, Thokozani Justin Kunene i Lagouge Kwanda Tartibu. "A Ffowcs Williams-Hawkings numerical aeroacoustic study of varied and fixed-pitch blades of an H-Rotor vertical axis wind turbine". MATEC Web of Conferences 347 (2021): 00013. http://dx.doi.org/10.1051/matecconf/202134700013.
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The effects of sound pressure level at two observation positions of a fixed and varied blade pitch angle at Low-Mach unsteady incompressible Reynolds-Average Navier-Stokes flow approach, on an H-rotor Vertical Axis Wind Turbine. The objective of the study is to compare the noise dissipation and output power/energy of the airfoil blades design of the vertical axis wind turbine in residential zones. The Ffowcs Williams-Hawkings (FHWH) techniques were applied to validate the output noise and vortex shedding of the different angles of attacks (AoA). The study postulated that the time history of the calculated sound pressure level at two observers positions: the aeroacoustic, blade vortex interaction noise, flow separations, dynamic stall experience from varied angled of attacks are found to produces less noise and vortex shedding compared to the fixed angle of attack.
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Chelabi, Mohammed Amine, Mohammed Kamel Hamidou i Mohammed Hamel. "Effects of Cone Angle and Inlet Blade Angle on Mixed Inflow Turbine Performances". Periodica Polytechnica Mechanical Engineering 61, nr 3 (29.06.2017): 225. http://dx.doi.org/10.3311/ppme.9890.
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The development of the aerofoil-shaped turbomachine blades is of prime importance for achieving the appropriate deflection of a three dimensional flow through desired angles, to work at the same degree of incidence and thereby providing the required performances for the specific machine. The sensitivity of the rotor to incidence effects and tendency of the flow to separate from one or the other blade surface have given rise to considerations of the optimum incidence angle and cone angle for a mixed inflow turbine by a numerical investigation using the ANSYS-CFX code. In order to keep the rotor in the same casing some geometrical parameters have been hold constant and the Bezier polynomial is used to generate the new shape of the rotor blade when changing the cone angle magnitude.
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Nurdin, Akhmad, Dwi Aries Himawanto i Syamsul Hadi. "Study of the Effect of Bulb Ratio and Blade Angle on Propeller Turbine Performance in Horizontal Flow using Numerical Simulation". TEKNIK 41, nr 1 (18.05.2020): 9–13. http://dx.doi.org/10.14710/teknik.v41i1.25328.
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This paper discusses numerical simulations of horizontal flow propeller turbines. Static bulbs located before the turbine can be used to increase water velocity and potentially increase the turbine's performance. The blade angle affects the gap between the blades, and this will also affect the performance of the turbine. Numerical simulations were conducted by using software Solid Works Flow Simulation 2016 and by using five blades in a static state. This study aimed to determine the effect of the bulb ratio and blade angle on the propeller turbine characteristics on horizontal flow. Bulb Ratio variations used in this study were 0, 0.4, 0.6, and 0.8, while the angle variations used were 20, 25, and 30 degrees. Each variation was tested at 0.02 m3/second. The results of this study indicated that the bulb ratio 0.6 with the 25-degree blade angle produces the highest torque
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Delafin, Pierre-Luc, François Deniset, Jacques André Astolfi i Frédéric Hauville. "Performance Improvement of a Darrieus Tidal Turbine with Active Variable Pitch". Energies 14, nr 3 (28.01.2021): 667. http://dx.doi.org/10.3390/en14030667.
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Vertical axis turbines, also called Darrieus turbines, present interesting characteristics for offshore wind and tidal applications but suffer from vibrations and a lower efficiency than the more conventional horizontal axis turbines. The use of variable pitch, in order to control the angle of attack of the blades continuously during their rotation, is considered in this study to overcome these problems. 2D blade-resolved unsteady Reynolds-Averaged Navier–Stokes (RANS) simulations are employed to evaluate the performance improvement that pitching blades can bring to the optimal performance of a three-straight-blade vertical axis tidal turbine. Three pitching laws are defined and tested. They aim to reduce the angle of attack of the blades in the upstream half of the turbine. No pitching motion is used in the downstream half. The streamwise velocity, monitored at the center of the turbine, together with the measurement of the blades’ angle of attack help show the effectiveness of the proposed pitching laws. The decrease in the angle of attack in the upstream half of a revolution leads to a significant increase in the power coefficient (+40%) and to a better balance of the torque generated in the upstream and downstream halves. Both torque and thrust ripples are therefore significantly reduced.
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Feng, Zi Ming, Zhen Xu Sun, De Shi Zhang, Guang Ling Zhou i Chun Hong Li. "Swept Blade Aerodynamics Numerical Simulation of Super-Critical HP Stage Static Cascade". Applied Mechanics and Materials 29-32 (sierpień 2010): 554–59. http://dx.doi.org/10.4028/www.scientific.net/amm.29-32.554.
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Super-critical HP steam stage static blade cascade is as the prototype blade to numerical simulations. Different swept blades are made by changing the sweep angle and sweep height in order to study the effect of swept blade on aerodynamics characteristics of turbine static cascade. The numerical simulation sweep angle are made of ±10° and 0°,swept heights are 30% blade height. The turbine aerodynamics characteristics are analyzed by NUMECA software. The numerical simulation results indicate: that aft-sweep blades negative C-type pressure distribution increase the low energy fluid centralizing in end-wall corner and the end-wall secondary flow loss, but the loss is decreased at mid-span, depending on the baseline. But fore-sweep blades C-type pressure distribution decrease the low energy fluid centralizing in endwall corner and the endwall secondary flow loss, but the loss is increased at mid-span, depending on the baseline.
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Kuang, J. H., i B. W. Huang. "Mode Localization of a Cracked Blade Disk". Journal of Engineering for Gas Turbines and Power 121, nr 2 (1.04.1999): 335–41. http://dx.doi.org/10.1115/1.2817125.
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In this paper, the effect of blade crack on the mode localization of a rotating blade disk is studied. Pretwisted taper beams are used to simulate blades of a blade disk. The crack on the blade can be regarded as a local disorder of this periodically coupled blades system. An application of Hamilton’s principle and Galerkin’s method is used to formulate the equations of motion of the mistuned system. Effects of pretwisted angle, rotating speed, and crack depth of the blade on the in-plane and off-plane mode localizations of a rotating system are investigated. Numerical results indicate that the increase of rotating speed, pretwisted angle, and crack depth could enhance the localization phenomenon significantly.
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Kushwaha, R. L. "FINITE ELEMENT MODELLING OF TILLAGE TOOL DESIGN". Transactions of the Canadian Society for Mechanical Engineering 17, nr 2 (czerwiec 1993): 257–69. http://dx.doi.org/10.1139/tcsme-1993-0016.
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A non-linear finite element model was developed for three dimensional soil cutting by tillage tools. A hyperbolic constitutive relation for soil was used in the model. Analysis was carried out to simulate soil cutting with rectangular flat and triangular tillage blades at different rake angles and with curved blades. Interface elements were used to model the adhesion and the friction between soil and blade surface. Soil forces obtained from the finite element model for the straight blades were verified with the results from laboratory tillage tests in the soil bin. The finite element model predicted draft force accurately for both tillage tools. Results indicated that the draft was a function of rake angle, tool shape and the curvature.
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Zangeneh, M., M. Schleer, F. Pløger, S. S. Hong, C. Roduner, B. Ribi i R. S. Abhari. "Investigation of an Inversely Designed Centrifugal Compressor Stage—Part I: Design and Numerical Verification". Journal of Turbomachinery 126, nr 1 (1.01.2004): 73–81. http://dx.doi.org/10.1115/1.1645868.
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In this paper the three-dimensional inverse design code TURBOdesign-1 is applied to the design of the blade geometry of a centrifugal compressor impeller with splitter blades. In the design of conventional impellers the splitter blades normally have the same geometry as the full blades and are placed at mid-pitch location between the two full blades, which can usually result in a mismatch between the flow angle and blade angles at the splitter leading edge. In the inverse design method the splitter and full blade geometry is computed independently for a specified distribution of blade loading on the splitter and full blades. In this paper the basic design methodology is outlined and then the flow in the conventional and inverse designed impeller is compared in detail by using computational fluid dynamics (CFD) code TASCflow. The CFD results confirm that the inverse design impeller has a more uniform exit flow, better control of tip leakage flow and higher efficiency than the conventional impeller. The results also show that the shape of the trailing edge geometry has a very appreciable effect on the impeller Euler head and this must be accurately modeled in all CFD computations to ensure closer match between CFD and experimental results. Detailed measurements are presented in part II of the paper.
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Ahmed Kadhim Abbood i Majed Salih Himoud. "Effect of rotary plow with different blades, plow cover height and different forward speed on some soil physical traits". University of Thi-Qar Journal of agricultural research 12, nr 1 (8.06.2023): 44–67. http://dx.doi.org/10.54174/utjagr.v12i1.238.
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This research was conducted to study the effect of different forms of rotary plow blades s on clay loam soils, through the use of three forms of blades (traditional blades (T1) and locally manufactured blades (T2 and T3)), and two forward plowing speeds (3.85 and 6.04) km. ̄ ¹ hour, two rotary tiller hood opening angles (35˚ and 70˚)and the study of its effect on the physical properties of clay soil: penetration resistance, average volume of stirred soil, percentage of earth masses with diameters less than 5 cm m², bulk density of soil, and total porosity. The research was carried out using the split split plank method according to the randomized complete block design (C.R.D) and with three replicates for each treatment. The results showed that the forward speed (3.85) kmh ̄ ¹ has achieved the best soil resistance to penetration. While the forward velocity (6.04) kmh ̄ ¹ achieved the best values for each soil volume rate, soil bulk density and total porosity. The angle (35˚) recorded the best values for each of the soil resistance to penetration and the proportion of soil masses, while the angle (70˚) excelled in recording the best values for each average of the volume of the soil stirred up, bulk density and porosity. The blades ((T3) was significantly excelled on the two blades (T1 and T2) in achieving the best values of penetration resistance, average volume of soil stirred up, mass ratio, bulk density, and porosity. As for the overlap between the two forward speeds and cover angles of the plow, the speed was (3.85) km per hour ̄ ¹ With angle ((35˚) best values for penetration resistance,As for the speed (6.04) km h ̄ ¹ with an angle ((70˚), the best values were recorded for the average volume of the stirred soil, bulk density and porosity. As for the interaction between the two speeds and the shape of the blades, the blades (T3) excelled at the forward speed (3.85) km/h ̄ ¹ in giving the best value for resistance to penetration. While the blades itself gave at the speed (6.04) kmh ̄ ¹ the best values for the average volume of soil stirred up. As for the overlap between the angles of cover for the plow and the shape of the blades, the blades (T3) excelled at the angle (70˚) in achieving the best values for the average volume of soil stirred up and density virtual and porous, At the angle (35˚), the blades achieved the best value of penetration resistance and the percentage of soil masses. As for the interaction between the two forward speeds of plowing, the angles of the opening of the rotary plow cover and the shape of blades, there were no significant differences in the physical traits of soil.
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Hsu, Ming-Hung. "Dynamic Analysis of Wind Turbine Blades Using Radial Basis Functions". Advances in Acoustics and Vibration 2011 (17.08.2011): 1–11. http://dx.doi.org/10.1155/2011/973591.
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Wind turbine blades play important roles in wind energy generation. The dynamic problems associated with wind turbine blades are formulated using radial basis functions. The radial basis function procedure is used to transform partial differential equations, which represent the dynamic behavior of wind turbine blades, into a discrete eigenvalue problem. Numerical results demonstrate that rotational speed significantly impacts the first frequency of a wind turbine blade. Moreover, the pitch angle does not markedly affect wind turbine blade frequencies. This work examines the radial basis functions for dynamic problems of wind turbine blade.