Relevant bibliographies by topics / Synthetic chord

Academic literature on the topic 'Synthetic chord'

Author: Grafiati
Published: 10 December 2022
Last updated: 28 January 2023

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Journal articles on the topic "Synthetic chord"

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Lin, C. Y., and F. B. Hsiao. "Experimental Study of Flow Separation over NACA633018 Wing with Synthetic Jet Control at Low Reynolds Numbers." Journal of Mechanics 29, no. 1 (October 16, 2012): 45–52. http://dx.doi.org/10.1017/jmech.2012.120.

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AbstractThis paper experimentally studies flow separation and aerodynamic performance of a NACA633018 wing using a series of piezoelectric-driven disks, which are located at 12% chord length from the leading edge to generate a spanwise-distributed synthetic jets to excite the passing flow. The experiment is conducted in an open-type wind tunnel with Reynolds numbers (Re) of 8 × 104 and 1.2 × 105, respectively, based on the wing chord. The oscillations of the synthetic jet actuators (SJAs) disturb the neighboring passage flow on the upper surface of the wing before the laminar separation takes place. The disturbances of energy influence the downstream development of boundary layers to eliminate or reduce the separation bubble on the upper surface of the wing. Significant lift increase and drag decrease are found at the tested Reynolds number of 8 × 104 due to the actuators excitation. Furthermore, the effect of drag also reduces dominant with increasing Reynolds number, but the increase on lift is reduced with the Reynolds number increased.
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Perju, Veaceslav. "SYSTEMS FOR INVARIANT TARGET RECOGNITION BASEDON CENTRAL IMAGE CHORD TRANSFORMATION." Journal of Engineering Science 29, no. 1 (March 2022): 71–85. http://dx.doi.org/10.52326/jes.utm.2022.29(1).06.

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Target recognition (TR) is widely used in different military and civil applications and permits enhanced intelligence and autonomously operating platforms design. The article describes existing systems for TR such as deep learning aided computer vision; target tracking architecture, based on the tracking-by-detection paradigm; a target detection dataset; deep neural networks; a system for the management of a plurality of sensors; a target recognition architecture, adaptive to operational conditions and a target detection system, based on the theory of multi-temporal recognition. Unfortunately, the existing systems do not orient for real-time processing or can be applied for synthetic aperture radar images only, or used for image processing of soft targets, etc. This article presents the data regarding proposed new systems for targets recognition and determination of their parameters, based on central image chord transformation. The systems’ main processing units are described. The structures of the elaborated systems and the principles of their functioning are presented. The models of data processing flow in the systems are described. The determination of the processing time of the operations, realized in the systems was made and the estimation of the throughput of the systems was done. The optimization of the elaborated systems was made. The results regarding systems’ characteristics are presented.
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KOTAPATI, RUPESH B., RAJAT MITTAL, OLAF MARXEN, FRANK HAM, DONGHYUN YOU, and LOUIS N. CATTAFESTA. "Nonlinear dynamics and synthetic-jet-based control of a canonical separated flow." Journal of Fluid Mechanics 654 (May 11, 2010): 65–97. http://dx.doi.org/10.1017/s002211201000042x.

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A novel flow configuration devised for investigation of active control of separated airfoil flows using synthetic jets is presented. The configuration consists of a flat plate, with an elliptic leading edge and a blunt trailing edge, at zero incidence in a free stream. Flow separation is induced on the upper surface of the airfoil at the aft-chord location by applying suction and blowing on the top boundary of the computational domain. Typical separated airfoil flows are generally characterized by at least three distinct frequency scales corresponding to the shear layer instability, the unsteadiness of the separated region and the vortex shedding in the wake, and all these features are present in the current flow. Two-dimensional Navier–Stokes simulations of this flow at a chord Reynolds number of 6 × 104 have been carried out to examine the nonlinear dynamics in this flow and its implications for synthetic-jet-based separation control. The results show that there is a strong nonlinear coupling between the various features of the flow, and that the uncontrolled as well as the forced flow is characterized by a variety of ‘lock-on’ states that result from this nonlinear coupling. The most effective separation control is found to occur at the highest forcing frequency for which both the shear layer and the separated region lock on to the forcing frequency. The effects of the Reynolds number on the scaling of the characteristic frequencies of the separated flow and its subsequent control are studied by repeating some of the simulations at a higher Reynolds number of 1 × 105.
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Singh, Deepak Kumar, Anuj Jain, and Akshoy Ranjan Paul. "Active Flow Control over a NACA23012 Airfoil using Hybrid Jet." Defence Science Journal 71, no. 6 (October 22, 2021): 721–29. http://dx.doi.org/10.14429/dsj.71.16468.

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A time-dependent numerical simulation is performed to examine the flow separation control with the action of a hybrid jet (the combination of synthetic and continuous jets) over a NACA23012 airfoil. The unsteady Reynolds-averaged Navier–Stokes (URANS) simulation is performed with Spalart-Allmaras (SA) turbulence model to simulate the flow field around the airfoil to analyse the effect of the hybrid jet. A combined jet is placed at the point of flow separation on the upper surface of the airfoil which is located at the 12% of the chord length from the leading edge of the airfoil for a given flow configuration. Flow simulations are performed at a chord-based Reynolds number of 2.19 × 106 for the hybrid jet oscillating frequency of 0.159 at a blowing ratio of 3.0. The contribution of the continuous jet in the hybrid jet is evident by the flow control. Variation in the continuous jet velocity is studied, which improved the aerodynamic characteristics of the airfoil. The maximum improvement in lift to drag ratio is observed from 11.19 to 22.14 at an angle of attack of 22 degree. The stall angle also shows an enhancement from 18 degree to 20 degree.
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Bozinoski, Radoslav, and Roger L. Davis. "A DES Procedure Applied to a Wall-Mounted Hump." International Journal of Aerospace Engineering 2012 (2012): 1–11. http://dx.doi.org/10.1155/2012/149461.

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This paper describes a detached-eddy simulation (DES) for the flow over a wall-mounted hump. The Reynolds number based on the hump chord isRec=9.36×105with an in-let Mach number of 0.1. Solutions of the three-dimensional Reynolds-averaged Navier-Stokes (RANS) procedure are obtained using the Wilcoxk−ωequations. The DES results are obtained using the model presented by Bush and Mani and are compared with RANS solutions and experimental data from NASA's 2004 Computational Fluid Dynamics Validation on Synthetic Jets and Turbulent Separation Control Workshop. The DES procedure exhibited a three-dimensional flow structure in the wake, with a 13.65% shorter mean separation region compared to RANS and a mean reattachment length that is in good agreement with experimental measurements. DES predictions of the pressure coefficient in the separation region also exhibit good agreement with experiment and are more accurate than RANS predictions.
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Srinath, R., R. Mukesh, Manish C. Poojari, Inamul Hasan, and Wubetu Amare Alebachew. "Streamline Effect Improvement of Additive Manufactured Airfoil Utilizing Dynamic Stream Control Procedure." Advances in Materials Science and Engineering 2022 (September 17, 2022): 1–12. http://dx.doi.org/10.1155/2022/1252681.

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In the era of fast transport, to create inventive stream flow management solutions that are capable of diminishing the aerodynamic drag of the vehicles, there is a need to modify the flow characteristics over the vehicle by deferring or expelling the position of the flow partition. The objective of this study involves the parameterized design of an airfoil utilizing the Bezier curve technique with the assistance of the simulation program. For flow regulations, synthetic jet modules are ingrained at different percentages of the chord to manage the stall characteristics. The parametrization system, combined with the stream control method, can give a much better insight into flow re-energization and pave some way for the reduction of the wake. Digital fabrication technique (3d printing or Rapid Prototyping method) is used to fabricate the end product for aerodynamic testing. The comparative outcome showed a reduction in drag at certain angles of attack due to the surface finish obtained. By comparing the results, the aerodynamic efficiency showed a significant rise of 13.05% at lower angles of attack when compressed gas was used in the synthetic jet closer to the frontier edge of the airfoil. Near the stall angle of attack, the coefficient of lift (Cl) and coefficient of drag (Cd) values showed no progress.
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Al-Am, Jean, Vincent Clair, Alexis Giauque, Jérôme Boudet, and Fernando Gea-Aguilera. "A Parametric Study on the LES Numerical Setup to Investigate Fan/OGV Broadband Noise." International Journal of Turbomachinery, Propulsion and Power 6, no. 2 (May 26, 2021): 12. http://dx.doi.org/10.3390/ijtpp6020012.

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In the present paper, large eddy simulations are performed to study two different mechanisms of Fan/OGV broadband noise: airfoil self-noise and turbulence interaction noise. Firstly, the current study focuses on the prediction of airfoil self-noise from a thin plate with a sharp trailing edge and a chord-based Reynolds number of the order of 106. The boundary layer is tripped to trigger transition to turbulence, and a parameter study is performed to study the influence of the near-wall modeling, grid topology and refinement in the near-wall and wake regions, the spanwise domain extent, and the tripping method. Empirical and analytical models, as well as available DNS data are used for validation purposes. Secondly, the interaction noise from a thin plate impinged by an incoming synthetic turbulent flow is studied. For both cases, far-field acoustic spectra are compared to Amiet’s models for leading and trailing edge noise showing a good agreement.
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van Oudheusden, B. W., E. W. F. Casimiri, and F. Scarano. "Aerodynamic load characterisation of a low speed aerofoil using particle image velocimetry." Aeronautical Journal 112, no. 1130 (April 2008): 197–205. http://dx.doi.org/10.1017/s000192400000213x.

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AbstractParticle image velocimetry (PIV) measurements of the flow around a wing section are employed as a basis for non-intrusive aerodynamic mean loads characterisation, providing sectional lift, drag and pitching moment. The technique relies upon the application of control-volume approaches in combination with the deduction of the pressure from the PIV experimental data through application of the momentum equation. The treatment can also be applied when the flow is unsteady; in that case time-mean loads are obtained from velocity statistics, through the use of Reynolds-averaged formulation of the governing equations. The procedure was applied in the experimental investigation of a NACA 642A015 aerofoil, in which the PIV approach is validated against standard pressure-based methods (surface pressure distribution and wake rake). The chord Reynolds number considered in the investigation ranges between 1 – 7 × 105. In addition, the consistency and potential performance of the method was assessed by means of synthetic velocity field data obtained from a numerical flow simulation.
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SAHNI, ONKAR, JOSHUA WOOD, KENNETH E. JANSEN, and MICHAEL AMITAY. "Three-dimensional interactions between a finite-span synthetic jet and a crossflow." Journal of Fluid Mechanics 671 (February 9, 2011): 254–87. http://dx.doi.org/10.1017/s0022112010005604.

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A complementary experimental and numerical investigation was performed to study the three-dimensional flow structures and interactions of a finite-span synthetic jet in a crossflow at a chord-based Reynolds number of 100,000 and a 0° angle of attack. Six blowing ratios in the range of 0.2–1.2 were considered. Experiments were conducted on a finite wing with a cross-sectional profile of NACA 4421, where particle-image velocimetry data were collected at the centre jet. To complement the experiments, three-dimensional numerical simulations were performed, where the numerical set-up matched not only the physical parameters (e.g. free stream) but also the physical dimensions (e.g. orientation and location of the jet. For the low blowing ratio cases, spatial non-uniformities developed, due to the finite span of the slit, which led to the formation of small and organized secondary structures or a streak-like pattern in the mean flow. On the other hand, for the high blowing ratio range, turbulent vortical structures were dominant, leading to larger spanwise structures, with a larger spanwise wavelength. Moreover, the phase-locked flow fields exhibited a train of counter-rotating coherent vortices that lifted off the surface as they advected downstream. In the mid-blowing ratio range, combined features of the low range (near the slit) and high range (in downstream locations) were found, where a pair of counter-rotating vortices issued in the same jet cycle collided with each other. In all cases, the spanwise extent of the secondary coherent structures reduced with downstream distance with a larger decrease at higher blowing ratios. Similar observations were made in earlier studies on finite-span synthetic jets in quiescent conditions.
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Chen, J., D. L. Brower, and T. Benedett. "Faraday-effect polarimetry for current profile measurement in the tokamak plasma edge." Review of Scientific Instruments 93, no. 8 (August 1, 2022): 083515. http://dx.doi.org/10.1063/5.0101550.

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Toroidal current profile measurements in the tokamak plasma edge are critical for fusion plasma physics research and model validation. A three-wave Faraday-effect polarimeter-interferometer with a sub-centimeter spatial resolution is proposed on the DIII-D tokamak to determine the edge current profile via Abel inversion. By using probe beams with 316 µm wavelength, a low-field-side, vertical-view, single-pass optical layout covering the plasma edge region (R = 2.15–2.27 m) is assessed. Measurements with no greater than 0.1° polarimetric systematic uncertainty, no greater than 0.01° polarimetric root-mean-square noise (1 kHz bandwidth), and a 0.8 cm radial chord spacing are considered feasible based on the achieved performance of existing systems using similar wavelengths on fusion devices. Synthetic diagnostic calculations taking various factors into account, such as diagnostic uncertainty and quality of magnetic flux surfaces, find that the edge current profile can be determined with up to 0.12 MA/m2 uncertainty, or about 10% of the peak current density in the pedestal of an investigated high-confinement plasma.
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Dissertations / Theses on the topic "Synthetic chord"

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Miller, Courtney Jade. "A New Tonality: Synthetic chords and transpositional paths in piano sonatas 1, 2 and 5 by Nikolai A. Roslavets." Thesis, 2021. https://hdl.handle.net/2440/134588.

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This analytical study, submitted for the degree of Master of Philosophy at the Elder Conservatorium of Music, University of Adelaide, aims to provide insight into the compositional system of Nikolai Andreevich Roslavets, a modernist composer active from 1901 until 1942, by analysing the synthetic chords and transpositional paths present in the three surviving sonatas for piano, Sonata No. 1 (1914), Sonata No. 2 (1916) and Sonata No. 5 (1923). The innovative approach to composition pioneered by Roslavets led him to create a highly original system built around his synthetic chords, which he described as preceding the entire harmonic plan of the work. To understand the harmonic basis of the compositional system, the study analyses the synthetic chords of the selected works. These analyses aim to provide insight into the role of these chords as an abstract, pre-compositional tool providing the pitch material for the compositions; touch upon their use as a ‘deputy for tonality’, using certain chords as replacements for the traditional IV and V chords in diatonic harmony; address the vertical and horizontal treatment of the chords; and uncover the symmetry of the transpositional paths and their effect on the architecture of each composition. This research aims to increase understanding of this music by focussing attention on these pioneering developments in the hope that it will be of benefit to composers, performers, and researchers. The submission seeks to reveal the compositional methods used by the composer by uncovering the authentic pre-compositional material inherent to each sonata, and using this information to decode the different types of transpositional paths and resulting symmetries present. This submission is presented as a conventional text-based dissertation supported by analytical tables and annotated musical examples.
Thesis (MPhil) -- University of Adelaide, Elder Conservatorium of Music, 2022
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Wu, Chung-chang, and 吳俊璋. "Synthesis and Thermal Analysis of 2-choro-1-formylcyclopent-1-ene." Thesis, 2003. http://ndltd.ncl.edu.tw/handle/53086910540827022108.

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碩士
國立高雄第一科技大學
環境與安全衛生工程所
91
The Vilsmeier reagent formed from N, N-dimethylformamide and phosphorus oxychloride, could proceed with the electrophilic displacement with aromatic, that is so-called Vilsmierier-Haack reaction. In the reaction, the experiment modified the temperature from 60℃ to 0~5℃. The original method, related with the extraction, is modified with the property of exchanging solvent. And at the same time, the experiment reduce the pressure of distillation in the 40℃, 50℃ and 60℃ to test the product’s purity at the different degrees of vacuum. It is the easiest method to separate the product from the solvent in the 50℃ and 1 torr. Discussing about the reaction process, the experiment used the thermal analysis instrument, (Differential scanning calorimetry, DSC), to study its thermal action. Quantitative information of reaction is needed for the process control and safety. Alkenes and aldehyde’s property are not stable. If the products stay in the air, the auto-reaction will happen. Accordingly, it measured its structural variation when the auto-reaction happened, and recorded it by fourier-tracnform spectrophotometer at the same time. It is verified by NMR that aldehyde causes the auto-reaction. We can use the gas chromatography/mass spectrometry to measure the molecular weight of its by-product. At the result, the emperiment promote the operation of synthesis, and better understand the thermal stability and the auto-reaction by product. Key word: Vilsmeier、Electrophilic displacement、exchanging solvent
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Book chapters on the topic "Synthetic chord"

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Rode, Alan K. "Pre-Code in Synthetic Flesh." In Michael Curtiz. University Press of Kentucky, 2017. http://dx.doi.org/10.5810/kentucky/9780813173917.003.0014.

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Curtiz’s career is summarized during the pre-Code era of Hollywood films. The evolution of the Production Code from the 1922 appointment of Will Hays as the czar of the MPPDA to the lack of enforcement of the Code is contextually chronicled as a key driver of the nature of Warner Bros. pictures during the early years of the Depression. Zanuck pioneered the “ripped from the headlines” gangster dramas that struck a chord with audiences. After he directed The Mad Genius, with John Barrymore, Curtiz’s pay was cut as Warners lost $8 million in 1931.Following The Woman from Monte Carlo and the visually creative Alias the Doctor, Curtiz was assigned the contemporary Strange Love of Molly Louvain, starring Ann Dvorak.He hit box-office gold with Doctor X (1932), a gruesome pre-Code horror film starring Fay Wray, who recounted Curtiz’s cold, sometimes cruel behavior on the set. Curtiz’s production of The Cabin in the Cotton included his racial faux pas and his alienation of Bette Davis during their first film together.His masterly direction of 20,000 Years in Sing Sing concluded a year of worsening economic conditions for the country.
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Conference papers on the topic "Synthetic chord"

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Beorkrem, Christopher, and Dan Corte. "Zero-Waste, Flat-Packed, Tri-Chord Truss: Continued Investigations of Structural Expression in Parametric Design"." In ACADIA 2012: Synthetic Digital Ecologies. ACADIA, 2012. http://dx.doi.org/10.52842/conf.acadia.2012.199.

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Beorkrem, Christopher, and Dan Corte. "Zero-Waste, Flat-Packed, Tri-Chord Truss: Continued Investigations of Structural Expression in Parametric Design"." In ACADIA 2012: Synthetic Digital Ecologies. ACADIA, 2012. http://dx.doi.org/10.52842/conf.acadia.2012.199.

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Byambatsogt, Gerelmaa, Gou Koutaki, and Lodoiravsal Choimaa. "Improved Chord Recognition using Synthetic Data Generation by Robot." In 2019 IEEE 8th Global Conference on Consumer Electronics (GCCE). IEEE, 2019. http://dx.doi.org/10.1109/gcce46687.2019.9015511.

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Abdi, A., M. Tadjfar, and M. Bayati. "Influence of Tangential Synthetic Jet Location on Flow Control." In ASME 2016 Fluids Engineering Division Summer Meeting collocated with the ASME 2016 Heat Transfer Summer Conference and the ASME 2016 14th International Conference on Nanochannels, Microchannels, and Minichannels. American Society of Mechanical Engineers, 2016. http://dx.doi.org/10.1115/fedsm2016-7655.

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A numerical study of separation control has been made to investigate aerodynamic characteristics of a NACA0012 airfoil with a tangential synthetic jet. Simulations are carried out at the chord Reynolds number of Re=1,000,000. The present approach relies on solving the Unsteady Reynolds-Averaged Navier–Stokes (URANS) equations. The turbulence model used in the present computation is the K-ω SST equations. All computations are performed with a finite volume based code. We have varied the synthetic jet position on the suction side of the airfoil at various locations from 4% of the chord all the way up to 60% of the airfoil chord. The jet oscillating frequency of fj = 15 Hz, (which corresponds to the non-dimensional oscillating frequency of Fjet+ = 1 when the jet is placed at the 12% chord location), and the blowing ratio of Vj/U∞ = 2 are used during the control cycle. All the cases considered here are for the airfoil at the constant angle of attack of α = 19°, where the airfoil stalls in the uncontrolled base flow. We found that stall characteristics are significantly improved by controlling the formation of separation vortices in the flow. The airfoil lift is more than doubled by placing the tangential synthetic jet anywhere between 20% chord to 50% chord location. This corresponds to a 25% improvement over the best cases reported by Chapin and Benard (2015) for a cross flow synthetic jet.
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Neve, Mayuresh, V. R. Kalamkar, and Akshay Wagh. "Numerical Analysis of NACA Aerofoil Using Synthetic Jet." In ASME 2017 Gas Turbine India Conference. American Society of Mechanical Engineers, 2017. http://dx.doi.org/10.1115/gtindia2017-4587.

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Usually at high angle of attack, aerofoil stalls due to flow separation on suction surface of aerofoil. To delay the flow separation, pulsating jet arrangement, known as Synthetic jet is used in aerofoil. It is produced by periodic suction and ejection of fluid from an orifice. This condition can be achieved by inducing movement to diaphragm or by giving a zero mass flux sinusoidal boundary condition to the jet. This allows the reattachment of boundary layer which improves the lift and drag performance and angle at also delays stalling angle. In present study, CFD analysis on NACA0015 aerofoil is performed for different angles of attack and the Co-efficients of Drag (Cd) and Lift (C1) are validated with the experimental results of Gilarranz et al. [1]. The flow is simulated by solving Unsteady RANS coupled with k-ε realizable turbulence model with enhanced wall treatment. Synthetic jet is placed in NACA0015 airfoil at 12% of the chord length with width as 0.53% of chord and is studied for a Reynolds number Re = 8.96 × 105 and for angle of attack from 12 to 20 degrees [2]. The jet is almost tangential to the wall at an angle, αjet = 10° and chord length is considered as 0.375m for the study. Further, parametric analyses are conducted on NACA 0015 aerofoil to investigate effect of parameters (frequency, jet angle, jet velocity). It is observed that aerofoil’s performance is improved significantly for jet angle (30°–40°), jet frequency (100 Hz) and non dimensional jet velocity (1.8–2.0). A maximum increase of approximately 26% in Lift was observed at AOA 20°.
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Zeynali Khameneh, Nooshin, and Mehran Tadjfar. "Improvement of Wind Turbine Efficiency by Using Synthetic Jets." In ASME 2016 Fluids Engineering Division Summer Meeting collocated with the ASME 2016 Heat Transfer Summer Conference and the ASME 2016 14th International Conference on Nanochannels, Microchannels, and Minichannels. American Society of Mechanical Engineers, 2016. http://dx.doi.org/10.1115/fedsm2016-7959.

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In this paper we investigated the applicability of using synthetic jets to improve the efficiency of wind turbines. We used the NREL Phase VI rotor which is a stall regulated two bladed wind turbine with linear taper and nonlinear twist distribution over the blades and uses the S809 airfoil from root to tip. We validated our base flow (uncontrolled) results with the experimental tests that were performed in the NASA/AMES 80 ft. × 120 ft. wind tunnel. Synthetic jet is an active flow control device and was applied along the blade from root to tip at 0.1 chord location. The non-dimensionalized jet frequencies of Fjet+ = 1 and 0.5 and the blowing ratio of Vj/U∞ = 1 and 2 are used during the control cycle.
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Siauw, Wei Long, Jean Tensi, Se´bastien Bourgois, Jean-Paul Bonnet, Jean-Marc Breux, and Ignacio Maria. "Control of Flow Separation and Its Associated Physics on a NACA0015 Using Synthetic Jet Actuators." In ASME 2006 2nd Joint U.S.-European Fluids Engineering Summer Meeting Collocated With the 14th International Conference on Nuclear Engineering. ASMEDC, 2006. http://dx.doi.org/10.1115/fedsm2006-98519.

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Wind tunnel flow control experiments are conducted on two NACA0015 airfoil models, one of which having a chord length of 1.0m and the other having a chord of 0.35m, with the aim of exploring the separated flow physics and delaying flow separation. The larger model is tested in a low speed wind tunnel, measuring 1.25m by 1.25m at a Reynolds number of 0.4 and 0.27 million. This model is used to provide a quick proof of concept concerning the efficiency of various synthetic jet designs. Laser light visualization and Particle Image Velocimetry (PIV) studies are performed on this model. The synthetic jet actuators implemented (mechanically and acoustically generated) is realized through holes (2 and 3mm in diameter). The actuators are positioned at 20% or 70% of chord length from the leading edge for controlling separation at incidences between 12° and 15°. Flow separation delay and reattachment, depending on the frequency and momentum of the synthetic jet are observed qualitatively via laser sheet visualization in all cases. The efficiency of the actuator is quantified via the extent of separation observed with the PIV measurements. The technique of Proper Orthogonal Decomposition (POD) is applied to further reveal the large eddies in the separated shear layer and its interaction with the boundary layer. The smaller model is tested in a larger wind tunnel measuring 2.4m by 2.6m at a Reynolds number of 0.9 million. This is a more realistic flow condition with minimal wall and aspect ratio influence as compared to the larger model. The main experimental objective concerning this model is to quantify the baseline aerodynamic of the NACA0015 before implementation of synthetic jets. Laser light and surface oil visualizations are performed. Measurements concerning surface pressure and wake velocity characteristics are also made for this model. The lift of which is estimated via the integration of surface static pressure and the drag is estimated by wake survey technique using a pitot tube that is made to traverse in the wake. In addition, time resolved data are obtained in the wake of the airfoil by means of hotwires. Both hotwire measurement reveal typical Strouhal number of 0.34–0.4. These results are extrapolated to the large airfoil for interpretation of the flow physics during control. To sum up, the main results in the current study highlight the characteristics of the baseline airfoil and the ability of synthetic jet actuator techniques to obtain significant delay of the separation.
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Negahban, Mir Hossein, Musavir Bashir, and Ruxandra M. Botez. "Aerodynamic Optimization of a Novel Synthetic Trailing Edge and Chord Elongation Morphing: Application to the UAS-S45 Airfoil." In AIAA SCITECH 2023 Forum. Reston, Virginia: American Institute of Aeronautics and Astronautics, 2023. http://dx.doi.org/10.2514/6.2023-1582.

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Torres, Ricardo B., Gustaaf B. Jacobs, and Michael J. Cave. "Experimental Study on the Use of Synthetic Jet Actuators for Lift Control." In ASME Turbo Expo 2016: Turbomachinery Technical Conference and Exposition. American Society of Mechanical Engineers, 2016. http://dx.doi.org/10.1115/gt2016-56403.

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An experimental study on the use of synthetic jet actuators for lift control on a generic compressor airfoil is conducted. A wind tunnel model of a NACA 65(2)-415 airfoil, representative of the cross section of an Inlet Guide Vane (IGV) in an industrial gas compressor, is 3D-printed. Nine synthetic jet actuators are integrated within a planar wing section with their slots covering 61% of pressure side of the airfoil span, located 13% chord upstream of the trailing edge. The Helmholtz frequency of the slot is matched closely with the piezoelectric element material frequency. The slot is designed so that the bi-morph actuation creates a jet normal to the airfoil surface. By redirecting or vectoring the shear layer at the trailing edge, the synthetic jet actuator increases lift and decreases drag on the airfoil without a mechanical device or flap. Tests are performed at multiple Reynolds number ranging from Re=150,000 to Re=450,000. The increased lift of the integrated synthetic jet actuator is dependent on the Reynolds number and free stream velocity, the actuation frequency, and angle of attack. For actuation at 1450 Hz the synthetic jet actuator increases lift up to 7%. The synthetic jet increases L/D up to 15%. Velocity contours obtained through PIV show that the synthetic jet turns the trailing edge shear layer similar to a Gurney flap.
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Xu, K., P. Lavoie, and P. Sullivan. "Separation Control on an NACA 0025 Airfoil Using an Array of MEMS-Based Synthetic Jets." In ASME 2022 Fluids Engineering Division Summer Meeting. American Society of Mechanical Engineers, 2022. http://dx.doi.org/10.1115/fedsm2022-87621.

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Abstract An novel array of micro-electromechanical systems (MEMS) synthetic jets was designed to control flow separation by periodic blowing at two pre-determined frequencies on a NACA 0025 airfoil for a chord Reynolds number Rec = 105 and angle-of-attach α = 10°. The synthetic jets were generated by commercially available microblowers, providing ease of maintenance compared to other customized synthetic jet actuators. The velocity output of this jet array was characterized with hot-wire anemometry (HWA), and reattached flow was identified using smoke-wire visualization. Pressure measurements show that the array can suppress flow separation on the airfoil, resulting in 2.5 times lift recovery. From wake measurements, up to 50% drag reduction was achieved with the actuation of the jet array compared to the baseline (uncontrolled) case. Particle image velocimetry (PIV) was used to visualize the flow fields of the baseline case and two controlled cases. There was a significant difference in the scale of the vortices produced by the jet array and features of the reattached flow between the two actuation frequencies used.
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