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A Study on the Plasma Actuator Electrode Geometry Configurations for Improvement of the Aerodynamic Performance of an Airfoil
(Assoc Mechanical Engineers Technicians Slovenia, 2018) Akbiyik, Hurrem; Yavuz, Hakan; Akansu, Yahya Erkan
In this study, the induced flow effects of plasma generated by various types of electrode geometry configurations are presented. The model chosen for the study is a NACA0015 airfoil. The experiments are conducted in a wind tunnel at Reynolds number of 4.8x10(4). The plasma actuators mounted on the leading edge of the airfoil at chord position of 0.1 (x/C). The plasma actuators consist of an embedded and exposed electrode between which a dielectric material is placed. The applied voltage is set to 7 kV(pp). The excitation frequency is also set to 3.5 kHz. Three different electrode geometry configurations, namely as rinear, saw-tooth and square, are considered for the study. As a part of the experimental study, the two dimensional and three dimensional flow structures generated by the plasma actuators and related analysis results are presented. In addition, necessary measurements are also made to determine the drag and lift forces.
Active control of flow around a circular cylinder by using intermittent DBD plasma actuators
(ELSEVIER SCI LTD, 2017) Akbiyik, Hurrem; Akansu, Yahya Erkan; Yavuz, Hakan
In this study, for active control of flow, the effect of the Dielectric Barrier Discharge (DBD) plasma actuator consisting of intermittent electrodes in the lengthwise direction of circular cylinder is investigated. The experiments were conducted in the wind tunnel at the Reynolds numbers between 6000 and 12,500. In three different cases, the lengths of the actuators and gaps between them are chosen as 20 mm, 25 mm, and 50 mm, respectively. The applied voltage is in the range of 4.5-7.5 kVpp and the constantly applied frequency is 3.5 kHz for producing the plasma. By using the equally placed DBD plasma actuators for the circular cylinder, 2 dimensional flow structure in the wake region is converted into 3-dimensional flow structure that leads to reduce in the mean and fluctuating forces acting on the cylinder. The wake region is narrower than the plain cylinder at the middle point of the electrode spanwise position and the width of the wake region increases at the end point of the electrode spanwise position.
An Experimental Study on the Effectiveness of the Backward-Facing Step Technique on Small-Scale Horizontal-Axis Wind Turbine Rotor Blades
(Mdpi, 2024) Morina, Riad; Akansu, Yahya Erkan
The aim of this research work was to explore how modifying the design of small-scale HAWT rotor blades through the backward-facing step technique affects their efficiency under varying wind speeds. The study involved altering step parameters such as location, length, and depth to create four distinct stepped blade shapes and enhance the aerodynamic performance of a rotor with a diameter of 280 mm. A specific blade profile, NREL S822, was selected to meet both aerodynamic and structural criteria. The rotor models were examined at a Reynolds number of 4.7 x 104 for wind speeds between 8.5 and 15.5 m/s and tip-speed ratios between 2 and 5. The experimental results indicated that for certain geometric step parameter values, the efficiency of the rotor model (B3) increased by approximately 47% compared to the base model (B1), particularly for tip-speed ratios lower than around 3.2. However, beyond this point, the rotor efficiency dropped significantly, reaching approximately 60% in one case. Additionally, a hybrid rotor model (B6) was generated by combining the shape of the rotor model (B4) with the most efficient rotor model from the literature, generated using the leading-edge wavy shape technique. This hybrid rotor model enhanced rotor efficiency for specific values of tip-speed ratio and also ensured its smoother operation. Overall, the rotor model (B2), distinguished by smaller step parameter values and a shift as well as broadening of the power coefficient curve towards lower tip-speed ratio values, exhibited a higher peak power coefficient, approximately 1.4% greater than the base rotor (B1). This increase occurred at a lower tip-speed ratio, allowing the rotor to operate with higher efficiency across a broader range of tip-speed ratios.
An experimental study on the effects of uniform injection through one perforated surface of a square cylinder on some aerodynamic parameters
(ELSEVIER SCIENCE INC, 2007) Cuhadaroglu, Burhan; Akansu, Yahya Erkan; Turhal, Ahmet Oemuer
It is well known that injection/suction (transpiration) through a perforated surface is an efficient way of influencing the characteristics of a turbulent boundary layer. Injection application creates a thicker boundary layer on a flat plate and it thus decreases drag. In aeronautical applications, suction is frequently used to delay boundary layer separation. This paper presents an experimental study on the effects of uniform injection through one perforated surface of a square cylinder on the pressure distribution and drag coefficient in a two-dimensional turbulent flow. For this purpose, surface pressure measurements around a square cylinder have been performed at three different Reynolds numbers in a wind tunnel. The parameters taken into account were injection rate, position of perforated surface (i.e., front, top, and rear), and pressure coefficient and drag coefficient. The results show that variation in pressure coefficient around the square cylinder and drag coefficient were influenced by the position of perforated surface and by injection rate. (c) 2006 Elsevier Inc. All rights reserved.
Comparison of the Linear and Spanwise-Segmented DBD Plasma Actuators on Flow Control Around a NACA0015 Airfoil
(IEEE-Inst Electrical Electronics Engineers Inc, 2017) Akbiyik, Hurrem; Yavuz, Hakan; Akansu, Yahya Erkan
In this paper, linear and spanwise-segmented plasma actuator implementations as well as base airfoil with no plasma cases are presented. These approaches are used to control the flow around a NACA0015 airfoil. The experiments were conducted in a wind tunnel at Reynolds number of 3.6x10(4). The plasma actuators mounted on the leading edge of the airfoil at chord position of 0.1 (x/C). The electrical parameters used for the plasma generating device are set to constant values of 6-kV(pp) applied voltage and 3.5-kHz excitation frequency. It is observed that the use of spanwise-segmented plasma actuators converts the 2-D flow structure around the airfoil into 3-D forcing flow structure. The change of the wake region width of the airfoil is visualized by using the smoke-wire method. The flow visualization is performed at attack angles of 0 degrees, 5 degrees, 10 degrees, and 15 degrees. In addition, necessary measurements are also made to determine drag and lift forces. A comparative study on the drag and lift forces for the NACA0015 airfoil is performed. As a part of the conclusions, linear and spanwise-segmented plasma actuator implementations as well as base airfoil with no plasma cases are compared and related results on flow control are presented.
Control of flow around a square prism by slot jet injection from the rear surface
(ELSEVIER SCIENCE INC, 2010) Akansu, Yahya Erkan; Firat, Erhan
The flow around a square prism with slot jet injection from its base into the vortex formation region has been investigated experimentally for Reynolds number of 8000. For various injection rates, the mean and fluctuating pressure distributions on the square prism were measured and the velocity measurements were carried out by using a hot-wire anemometer. Flow visualization was performed by using the smoke-wire method. It was found that the slot jet injection has a substantial influence on the flow characteristics of the square prism. Increase of the injection ratio up to a certain value causes an important pressure recovery in the wake. For this lower range of blowing rates, blowing fluid tends to fill the wake region around the prism and extend it but the jet does not have enough momentum to penetrate the main vortices. By the further increasing of the blowing rate, the slot jet injection from the base side of the prism splits the near wake like a splitter plate. This causes a thinner wake width and weak vortices resulting in a higher vortex shedding frequency. (C) 2010 Elsevier Inc. All rights reserved.
CONTROL OF FLOW AROUND A SQUARE PRISM BY USING SYNTHETIC JET
(TECH UNIV LIBEREC, FAC MECHANICAL ENG, 2010) Akansu, Yahya Erkan; Firat, Erhan; Vit, T; Dancova, P
Control of the flow around a square prism by means of synthetic jet through a single slot located on middle of upper surface of the model has been investigated experimentally for Reynolds number of 8000. Synthetic jet was implemented by using a pneumatic piston-cylinder which was driven by means of an electrical motor. The frequency and stroke of the piston were changed to obtain various values of the flow control parameters. For various excitation frequency and momentum coefficients of the synthetic jet, the mean and fluctuating pressure distributions on the square prism were measured. The velocity measurements at the slot exit and at a specific coordinate were conducted by means of constant temperature anemometer (CTA). Vortex shedding frequencies obtained by the spectral analysis of both pressure-time and velocity-time history. At a value of synthetic jet excitation frequency, vortex pairs generated at slot were perturbed the shear layer that separated from the upper leading edge of square model and disturbs it. When the synthetic jet excitation frequency closes enough to the vortex shedding frequency, the lock-in of vortex shedding frequency onto the exciting frequency was occurred. On the other hand, increasing excitation frequency of the synthetic jet causes a pressure recovery on the surface of the prism within the wake region. The efficiency of the synthetic jet is classified depending on change of the drag coefficient and vortex shedding frequency.
EFFECT OF ATTACK ANGLE ON FLOW AROUND A SQUARE PRISM WITH A SPLITTER PLATE
(2018) Seyhan, Mehmet; Sarıoğlu, Mustafa; Akansu, Yahya Erkan
Lift and drag forces on a square prism with a (splitter) plate are experimentally investigated byforce measurements with a load cell. Results showed that drag and lift coefficients are independent ofReynolds number for Re = 9700 – 36500 at 0°, 45°, 90°, 135° and 180°. Drag coefficient at 0? is obtainedas 2.02 for the square prism alone, and 1.04 for the square cylinder with splitter plate. Maximum dragreduction for the square cylinder with the plate is 50% as compared to the square cylinder at 0? and 15.For ? < 30° and ? > 114°, drag coefficient of a square prism with splitter plate is smaller than that of thesquare prism alone. At Re = 20000, lift and drag coefficients significantly change with increasing attackangle
Effect of attack angle on the flow around adjacent circular and rectangular prisms
(2021) Seyhan, Mehmet; Sarıoğlu, Mustafa; Akansu, Yahya Erkan
An experimental investigation has been carried out to clarify the flow structure around adjacent circular and rectangular prisms. The measurements of hot-wire for Re= 4.1 x 103, 9.0 x 103 and 1.5 x 104, lift and drag force for Re = 1.0 x 104, and in addition the flow visualization experiments for Re = 2.3 x 103 have been performed in the range of 0° ? ? ? 180°. The adjacent bodies consist of a circular cylinder having 9.5 mm diameter and a rectangular prism having 6 mm x 10 mm cross-section attached to the circular cylinder from its short side in all the cases. The hot wire measurement results showed that the Strouhal number has Reynolds number independence for Re = 4.1x103, 9.0x103, and 1.5x104. Sudden peaks in St and lift coefficients are obtained for a similar reason that is reattachment of the separated shear layer in the vicinity of ? = 60? and 174?. For the adjacent bodies compared with the bare circular cylinder, 40%, and 25% drag reduction is obtained at ? = 0? and 174?, respectively. The obtained results show that the variations of lift coefficient, drag coefficient, and Strouhal number are strictly subjected to the attack angle.
Effect of plasma actuator and splitter plate on drag coefficient of a circular cylinder
(E D P SCIENCES, 2016) Akbiyik, Hurrem; Akansu, Yahya Erkan; Yavuz, Hakan; Bay, Ahmet Ertugrul; Dancova, P; Vesely, M
In this paper, an experimental study on flow control around a circular cylinder with splitter plate and plasma actuator is investigated. The study is performed in wind tunnel for Reynolds numbers at 4000 and 8000. The wake region of circular cylinder with a splitter plate is analyzed at different angles between 0 and 180 degrees. In this the study, not only plasma actuators are activated but also splitter plate is placed behind the cylinder. A couple electrodes are mounted on circular cylinder at +/- 90 degrees. Also, flow visualization is achieved by using smoke wire method. Drag coefficient of the circular cylinder with splitter plate and the plasma actuator are obtained for different angles and compared with the plain circular cylinder. While attack angle is 0 degree, drag coefficient is decreased about 20% by using the splitter plate behind the circular cylinder. However, when the plasma actuators are activated, the improvement of the drag reduction is measured to be 50%.
Effect of signal modulation of dbd plasma actuator on flow control around NACA 0015
(Turk Isı Bilimi ve Teknigi Dernegi, 2018) Güler, Adem Arif; Seyhan, Mehmet; Akansu, Yahya Erkan
Effects of DBD plasma actuator driven by six different type modulated signals on flow around NACA 0015 airfoil are experimentally investigated for lift augmentation. One actuator attached to the upside of the airfoil at x/c = 0.1 is used. Force measurement and smoke wire flow visualization are performed in a low speed wind tunnel. For Re= 3.6x104, the actuator is driven with six different signal modulations among which frequency modulation, amplitude modulation, excitation frequency and duty cycle at ? = 10°. SM4 including amplitude modulation is indicated to have better performance than the other signal modulations. Signal modulations provide energy savings while generating plasma to increase the lift coefficient. The obtained results indicate that as the dimensionless excitation frequency (F+) is 1 at low duty cycle, a better lift coefficient is obtained in comparison with the other F+ values. For Re= 3x104, the lift coefficient is proportionally increased with driving voltage and frequency due to increasing induced flow at ? = 10°. Flow visualization results showed that the separated shear layer at the leading edge gets closer to the (suction) surface of the airfoil by increasing the driving voltage from 6 kVpp to 8 kVpp which confirms the driving voltage effect. © 2018 TIBTD Printed in Turkey.
Effect of the duty cycle on the spark-plug plasma synthetic jet actuator
(E D P SCIENCES, 2016) Seyhan, Mehmet; Akansu, Yahya Erkan; Karakaya, Fuat; Yesildag, Cihan; Akbiyik, Hurrem; Dancova, P; Vesely, M
A promising novel actuator called Spark-Plug Plasma Synthetic Jet (SPSJ) has been developed in Atmospheric Plasma Research Laboratory at Nigde University. It generates electrothermally high synthetic jet velocity by using high voltage. SPSJ actuator can be utilized to be an active flow control device having some advantages such as no moving parts, low energy consumption and easy to integrate the system. This actuator consists of two main components: semi-surface spark plug (NGK BUHW) as an anode electrode and a cap having an orifice as a cathode electrode. The cap, having a jet exit orifice diameter of 2 mm, has diameter of 4.4 mm and height of 4.65 mm. This study presents the characteristics of SPSJ actuator by using the hot wire anemometer in order to approximately determine jet velocity in quiescent air. Peak velocity as high as 180 m/s was obtained for f(e) = 100 and duty cycle 50%. The flow visualization indicated that the actuator's jet velocity is enough to penetrate the developed boundary layer.
EFFECTIVE FLOW CONTROL AROUND A CIRCULAR CYLINDER BY USING BOTH A SPLITTER PLATE AND PLASMA ACTUATORS AS PASSIVE AND ACTIVE CONTROL METHODS
(Turkish Soc Thermal Sciences Technology, 2021) Akbiyik, Hurrem; Akansu, Yahya Erkan
In this study, passive and active flow control methods were used together to manipulate the flow around a circular cylinder. The experiments were conducted in a wind tunnel for the Reynolds number range of 4000 and 10000 based on the diameter of the circular cylinder (D). A splitter plate was used as passive flow control device and its length was chosen to be about 3.75D. Plasma actuators were placed on the circular cylinder at a position of +/- 90 degrees as an active flow control device. Combining the active and passive flow control methods, a greater reduction of the drag coefficient was achieved compared to that of the cases when using these methods separately. For Reynolds numbers of 5000 and 10000, the hybrid method gives a reduction in drag of 48% and 45%, respectively. The velocity measurements were carried out by using the hot-wire anemometry and velocity profiles were obtained in the wake region. The flow was visualized by using a smoke wire method. The results revealed that the wake region of the circular cylinder with plasma actuator and splitter plate has a narrower width than the plain cylinder and with splitter plate. Also, it can be seen from spectral analysis that the vortex shedding frequency was suppressed significantly by usage of the hybrid flow control method was used.
Experimental and numerical aerodynamic investigation of a prototype vehicle
(TECHNO-PRESS, 2015) Akansu, Selahaddin Orhan; Akansu, Yahya Erkan; Dagdevir, Toygun; Daldaban, Ferhat; Yavas, Feridun
This study presents experimental and numerical aerodynamic investigation of a prototype vehicle. Aerodynamics forces examined which exerted on a prototype. This experimental study was implemented in a wind tunnel for the Reynolds number between 105-3.1x10(5). Numerical aerodynamic analysis of the vehicle is conducted for different Reynolds number by using FLUENT CFD software, with the k-epsilon realizable turbulence model. The studied model aims at verifying the aerodynamic forces between experimental and numerical results. After the Reynolds number of 2.8x10(5), the drag coefficient obtained experimentally becomes independent of Reynolds number and has a value of 0.25.
Farklı Genlik ve Frekansa Sahip Ardışık Olarak Üretilen Sentetik Jetlerin Etkileşiminin İncelenmesi
(2018) Akansu, Yahya Erkan; Yalçın, Mehmet Kürşat; Sarıoğlu, Mustafa
Net kütle akısının sıfır oldugu sentetik jetler, periyodik olarak üfleme ve emme yapılmasına imkân saglayan piston-silindir mekanizması, piezoelektrik diyafram ve ses hoparlörünün kullanılması ile elde edilebilmektedir. Piston-silindir mekanizmalı sentetik jetler düsük frekanslarda büyük jet debilerine imkan saglarken, piezoelektrik diyaframlı veya hoparlör sistemli sentetik jetler ise düsük debilerde daha yüksek frekanslarda gerçeklesebilmektedir. Bu çalısmada hoparlör tipi sentetik jet aktuatörü istenilen sinyal yapısı ile sürülebilmesi sayesinde, farklı sentetik jet akıs yapıları olusturmak üzere kullanılmıstır. Sinyal yapısı, sinyal faz açısı, farklı genlik degerleri, duty cycle etkisi, ardısık sinyal üretilmesi, jet çıkıs geometrisinin sekli ve çapı gibi bir çok parametrenin ardısık olarak olusturulan jet yapıları ve çarpan jet ısı transferi üzerine etkileri deneysel olarak çalısılmıstır. Bu proje iki asamadan olusmaktadır. Birinci asamada, hoparlör tipi sentetik jet eyleyicinin sürüm sinyali degisken genlikli ve frekanslarda olacak sekilde modifiye edilerek sentetik jete ait akıs karakteristiklerinde performans artısının saglanmasına yönelik çalısmalar gerçeklestirilmistir. Projenin ikinci asamasında ise çarpan jet ısı transferi uygulamasında bu sinyal yapısının etkisinin ortaya konulmasıdır. Sabit genlikli ve frekanslı sinüzoidal sürümde periyodik olarak aynı yapıdaki sentetik jet halkaları olusmaktadır. Sinyal modülasyonu ile ardısık olarak üretilen jet halkaları farklı hız ve büyüklüklerde olusturarak belirli bir mesafe birleri ile birlesebilmektedir. Bu sayede, ısı transferi ve akıs kontrol çalısmaları için daha büyük bir etkinin olusturulması amaçlanmaktadır. Sinyal modülasyonu ile daha az güç tüketerek daha etkili sentetik jetin üretilmesine çalısılmıstır. Bu çalısmada lülenin çıkıs çapı D= 5, 10, 15, 20 ve 34 mm olacak sekilde lüle ve orifis olarak farklı jet çıkıs geometrileri kullanılmıstır. Farklı dalga yapılarına sahip sinyaller 4Hz-20Hz (Bazı durumlarda 50Hz?e kadar) arasında çesitli frekanslarda ve genliklerde olusturularak farklı yapılardaki ardısık jetlerin üretilmesi gerçeklestirilmistir. Jet bölgesinde çesitli y/D mesafelerinde kızgın tel anemometresi ile hız taraması yapılarak hem anlık ve ortalama hız dagılımları elde edilmistir. Isı transferi deneylerinde ise belirli mesafeye yerlestirilen ısıtılmıs levha üzerine sentetik jet halkaları çarptırılarak termal kamera ile levha üzerindeki sıcaklık ölçümlerinden ısı transfer katsayıları hesaplanmıstır. Bu projede hedeflenen iyilesmeler hem akıs kaynaklı problemlerin çözümü açısından hem de enerjinin daha verimli kullanılmasının saglanması açısından oldukça önemlidir. Sentetik jet akıs karakteristiklerinin iyilestirilmesi uçak kanatlarının sentetik jet ile aktif akıs kontrolünden, sogutma ve ısıtma uygulamalarına kadar birçok teknolojik ve endüstriyel alanda katkı saglayacak niteliktedir.
FLOW AROUND A SQUARE PRISM AND A CIRCULAR CYLINDER IN TANDEM ARRANGEMENT
(TECH UNIV LIBEREC, FAC MECHANICAL ENG, 2010) Akansu, Yahya Erkan; Yavuz, Tahir; Sarioglu, Mustafa; Vit, T; Dancova, P
Aerodynamic characteristics of flow around two bluff bodies of square and circular section in a tandem arrangement have been investigated experimentally at a Reynolds number of 2.2 x 10(4). Experiments were carried out in a wind tunnel for the various values of distance between the bodies in the range of 1 <= L/D <= 10. The upstream square prism side length and downstream circular cylinder diameter were equal to 25 mm. By using pressure transducer and hot-wire anemometer, mean pressure distributions and vortex-shedding from the square prism and circular cylinder were examined. Drag and lift coefficients were obtained from the integration of the pressure distributions. The Strouhal numbers of the test models were determined from the frequency analysis of the velocity fluctuations. A single smoke-wire was set in front of the bodies and the flow structure at the mid-span of test section was visualized at Re=7.0x10(3). Depending on the distance between the bodies, the positions of flow attachments, separations, reattachments and the structures of the vortex formation region have been clearly obtained from the flow visualization. According to the results, there are three basic flow structures in the case of the two tandem body arrangement depending on the distance between the bodies. These are "pattern I: single body behavior", "pattern II: shear layer reattachment" and "pattern III: vortex shedding between two bodies".
Flow field and heat transfer characteristics in an oblique slot jet impinging on a flat plate
(PERGAMON-ELSEVIER SCIENCE LTD, 2008) Akansu, Yahya Erkan; Sarioglu, Mustafa; Kuvvet, Kemal; Yavuz, Tahir
An experimental study was performed to determine the effects of inclination of an impinging two dimensional slot jet on the heat transfer from a flat plate. Local Nusselt numbers and surface pressure distributions were determined depending on inclination angle, jet-to-plate spacing and Reynolds number. The results showed that the location of maximum heat transfer was mainly due to the angle of inclination. As the inclination angle increases, the location of the maximum heat transfer shifts towards the uphill side of the plate and the value of the maximum Nusselt number gradually increases at lower jet-to-plate spacings. (C) 2008 Elsevier Ltd. All rights reserved.
Flow past a square prism with an upstream control rod at incidence to uniform stream
(PERGAMON-ELSEVIER SCIENCE LTD, 2015) Firat, Erhan; Akansu, Yahya Erkan; Akilli, Huseyin
In the numerical study, it was mainly intended to test the capability of a control rod to reduce the drag and to suppress the fluctuating forces acting on the rod-square (total) system for various angles of incidence (alpha) and center-to-center spacing ratios (L/D). The Reynolds numbers (Re) based upon the diameter of control rod and the side length of the square prism are 50 and 200, respectively, for the control rod and the square prism. Seven distinct flow patterns were observed and it was demonstrated that the cavity flow pattern is the most effective in terms of simultaneous reduction of the time-averaged and RMS values of fluctuating force coefficients for both control rod and square prism. As the control rod located 2D or 3D upstream of the square prism at zero angle of incidence, the time-averaged drag coefficient of the total system i.e. the sum of the time-averaged drag coefficients of the control rod and the square prism is about 74% that of the square prism alone. Furthermore, the maximum reductions in RMS values of the fluctuating lift acting on the total system are 53% and 60%, respectively, for 2D and 3D. On the other hand, the effectiveness of control rod in reducing the time-averaged drag coefficient of the total system was generally diminished with increasing a. Instantaneous and time-averaged flow fields were also presented in order to identify the flow patterns around the rod-square system. (C) 2015 Elsevier Ltd. All rights reserved.
INVESTIGATING THE EFFECTS OF PLASMA ACTUATOR ON THE FLOW CONTROL AROUND NACA2415 AIRFOIL
(Turkish Soc Thermal Sciences Technology, 2020) Sanlisoy, Aytac; Akansu, Yahya Erkan
In this study, the effects of the plasma actuator on flow control at varied Reynolds numbers and attack angles are examined. Plasma actuator is placed on the NACA2415 airfoil at x/C = 0.1. The effect of the actuator to active flow control is examined at Reynolds number between 8x10(3) and 9x10(4) in the wind tunnel. The lift force which acted on the airfoil was measured by using a force balance system. The velocity measurements were done by the hot-wire probe, located at the wake region, and the flow around model was visualized by the smoke wire method. When the plasma was active, an increased lift force and a narrowed wake region are observed. The stall angle shifted to the higher attack angle by the effective active flow control at low Reynolds numbers. Prevent of the flow separation was enhanced up to 18 degrees angle of attack and the maximum lift force occurred at the 14 degrees angle of attack which is doubled when the plasma actuator is on.
Investigation of S1046 profile bladed vertical axis wind turbine and artificial intelligence-based performance evaluation
(Taylor & Francis Inc, 2023) Osmanli, Suleyman; Akansu, Selahaddin Orhan; Azginoglu, Nuh; Akansu, Yahya Erkan; Develi, Ibrahim
It is very important to determine the parameters affecting the performance of the Darrieus-type wind turbine and its effects. In particular, it should be specified at which TSR value the peak power coefficient is obtained. In this study, standard and modified S1046 airfoils and aspect ratios (H/D), angle of attack (AoA), turbulent/non-turbulent flow (WT), number of blades (N), and chord length (C) were tested. Then, four different machines learning-based multi-output regression models (Decision Tree, Linear Regression, K-Nearest Neighbors, and Random Forest) were trained to make performance predictions with the data obtained from the evaluated test setup. Thirdly, feature selection based on the Random Forest algorithm, which is the best performing multi-output regression model, was performed using data due to changing parameter values on the established system. The importance of the parameters was determined. The operating range of the system was at relatively low TSR values. When analyzing the blade profile, the modified blade version performed better in certain combinations compared to the standard profile. Maximum power coefficient (Cp) was obtained from the modified turbine structure with 5 degrees of attack angle, H/D = 1.85, and C = 60 mm. The present study aims to increase the turbine's power coefficient and aims to predict results as power coefficient without doing many different experiments.

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