Showing papers on "Airfoil published in 2014"
TL;DR: In this paper, a multi-point high-fidelity aerostructural optimization of a long-range wide-body transonic transport aircraft configuration is presented, where the coupled adjoint sensitivity method is used to efficiently compute gradients, enabling the use of gradient-based optimization with respect to hundreds of aerodynamic shape and structural sizing variables.
Abstract: This paper presents multipoint high-fidelity aerostructural optimizations of a long-range wide-body transonic transport aircraft configuration. The aerostructural analysis employs Euler computational fluid dynamics with a 2-million-cell mesh and a structural finite-element model with 300,000 degrees of freedom. The coupled adjoint sensitivity method is used to efficiently compute gradients, enabling the use of gradient-based optimization with respect to hundreds of aerodynamic shape and structural sizing variables. The NASA Common Research Model is used as the baseline configuration, together with a wing box structure that was designed for this study. Two design optimization problems are solved: one where takeoff gross weight is minimized, and another where fuel burn is minimized. Each optimization uses a multipoint formulation with five cruise conditions and two maneuver conditions. Each of the optimization problems have 476 design variables, including wing planform, airfoil shape, and structural thickne...
335 citations
TL;DR: In this paper, the authors present the detailed formulation and validation results of simple and robust procedures for the generation of synthetic turbulence aimed at providing artificial turbulent content at the RANS-to-LES interface within a zonal wall-modelled LES of attached and mildly separated wall-bounded flows.
Abstract: The paper presents the detailed formulation and validation results of simple and robust procedures for the generation of synthetic turbulence aimed at providing artificial turbulent content at the RANS-to-LES interface within a zonal Wall Modelled LES of attached and mildly separated wall-bounded flows. There are two versions of the procedure. The aerodynamic version amounts to a minor modification of a synthetic turbulence generator developed by the authors previously, but the acoustically adapted version is new and includes an internal damping layer, where the pressure field is computed by “weighting” of the instantaneous pressure fields from LES and RANS. This is motivated by the need to avoid creating spurious noise as part of the turbulence generation. In terms of pure aerodynamics, the validation includes canonical shear flows (developed channel flow, zero pressure gradient boundary layer, and plane mixing layer), as well as a more complex flow over the wall-mounted hump with non-fixed separation and reattachment, with emphasis on a rapid conversion from modeled to resolved Reynolds stresses. The aeroacoustic applications include the flow past a trailing edge and over a two-element airfoil configuration. In all cases the methodology ensures a very acceptable accuracy for the mean flow, turbulent statistics and, also, the near- and far-field noise.
213 citations
TL;DR: In this paper, the effect of leading edge erosion on the aerodynamic performance of a wind turbine airfoil was investigated and the results showed that leading edge degradation can produce substantial airfoIL performance degradation, yielding a large increase in drag coupled with a significant loss in lift near the upper corner of the drag polar.
Abstract: This paper presents results of a study to investigate the effect of leading edge erosion on the aerodynamic performance of a wind turbine airfoil. The tests were conducted on the DU 96-W-180 wind turbine airfoil at three Reynolds numbers between 1 million and 1.85 million, and angles of attack spanning the nominal low drag range of the airfoil. The airfoil was tested with simulated leading edge erosion by varying both the type and severity of the erosion to investigate the loss in performance due to an eroded leading edge. Tests were also run with simulated bugs on the airfoil to assess the impact of insect accretion on airfoil performance. The objective was to develop a baseline understanding of the aerodynamic effects of varying levels of leading edge erosion and to quantify their relative impact on airfoil performance. Results show that leading edge erosion can produce substantial airfoil performance degradation, yielding a large increase in drag coupled with a significant loss in lift near the upper corner of the drag polar, which is key to maximizing wind turbine energy production. Copyright © 2013 John Wiley & Sons, Ltd.
203 citations
TL;DR: In this paper, a series of aerodynamic shape optimization studies using Reynolds-averaged Navier-Stokes computational fluid dynamics with a Spalart-Allmaras turbulence model is performed.
Abstract: The blended wing body is an aircraft configuration that has the potential to be more efficient than conventional large transport aircraft configurations with the same capability. However, the design of the blended wing is challenging due to the tight coupling between aerodynamic performance, trim, and stability. Other design challenges include the nature and number of the design variables involved, and the transonic flow conditions. To address these issues, a series of aerodynamic shape optimization studies using Reynolds-averaged Navier–Stokes computational fluid dynamics with a Spalart–Allmaras turbulence model is performed. A gradient-based optimization algorithm is used in conjunction with a discrete adjoint method that computes the derivatives of the aerodynamic forces. A total of 273 design variables—twist, airfoil shape, sweep, chord, and span—are considered. The drag coefficient at the cruise condition is minimized subject to lift, trim, static margin, and center plane bending moment constraints. ...
202 citations
TL;DR: In this paper, a laminar-turbulent transition model is proposed to model the growth of the maximum Tollmien-Schlichting instability amplitude in the presence of a boundary layer.
Abstract: A new laminar–turbulent transition model for low-turbulence external aerodynamic applications is presented that incorporates linear stability theory in a manner compatible with modern computational fluid dynamics solvers. The model uses a new transport equation that describes the growth of the maximum Tollmien–Schlichting instability amplitude in the presence of a boundary layer. To avoid the need for integration paths and nonlocal operations, a locally defined nondimensional pressure-gradient parameter is used that serves as an estimator of the integral boundary-layer properties. The model has been implemented into the OVERFLOW 2.2f solver. Comparisons of predictions using the new model with high-quality wind-tunnel measurements of airfoil section characteristics confirm the predictive qualities of the model, as well as its improvement over the current state of the art in computational fluid dynamics transition modeling at approximately half the computational expense.
163 citations
TL;DR: In this paper, an aerofoil undergoing pitch oscillations in ground effect, close to a solid boundary, is shown to increase the time-averaged lift and propulsive efficiency.
Abstract: Experimental and computational results are presented on an aerofoil undergoing pitch oscillations in ground effect, that is, close to a solid boundary. The time-averaged thrust is found to increase monotonically as the mean position of the aerofoil approaches the boundary while the propulsive efficiency stays relatively constant, showing that ground effect can enhance thrust at little extra cost for a pitching aerofoil. Vortices shed into the wake form pairs rather than vortex streets, so that in the mean a momentum jet is formed that angles away from the boundary. The time-averaged lift production is found to have two distinct regimes. When the pitching aerofoil is between 0.4 and 1 chord lengths from the ground, the lift force pulls the aerofoil towards the ground. In contrast, for wall proximities between 0.25 and 0.4 chord lengths, the lift force pushes the aerofoil away from the ground. Between these two regimes there is a stable equilibrium point where the time-averaged lift is zero and thrust is enhanced by approximately 40 %.
125 citations
TL;DR: In this article, the effect of tubercles on the flow structure over full-span modified wings based on the NACA 0021 profile, in the transitional flow regime, was investigated and it was found that a skew-induced mechanism accounts for the formation of streamwise vortices whose development is accompanied by flow separation in delta-shaped regions near the trailing edge.
Abstract: Wings with tubercles have been shown to display advantageous loading behavior at high attack angles compared to their unmodified counterparts. In an earlier study by the authors, it was shown that an undulating leading-edge configuration, including but not limited to a tubercled model, induces a cyclic variation in circulation along the span that gives rise to the formation of counter-rotating streamwise vortices. While the aerodynamic benefits of full-span tubercled wings have been associated with the presence of such vortices, their formation mechanism and influence on wing performance are still in question. In the present work, experimental and numerical tests were conducted to further investigate the effect of tubercles on the flow structure over full-span modified wings based on the NACA 0021 profile, in the transitional flow regime. It is found that a skew-induced mechanism accounts for the formation of streamwise vortices whose development is accompanied by flow separation in delta-shaped regions near the trailing edge. The presence of vortices is detrimental to the performance of full-span wings pre-stall, however renders benefits post-stall as demonstrated by wind tunnel pressure measurement tests. Finally, primary and secondary vortices are identified post-stall that produce an enhanced momentum transfer effect that reduces flow separation, thus increasing the generated amount of lift.
114 citations
TL;DR: A deeper insight is obtained into the lift generation mechanism involved in unsteady motion of the airfoil in order to improve the design of flow control techniques to exploit the dynamic stall process for a large range of applications.
104 citations
TL;DR: In this paper, the authors describe the development and the wind tunnel test of a variable geometry morphing airfoil using corrugated structures, which is verified by finite element analysis, and a prototype is manufactured using carbon fiber reinforced plastics.
Abstract: This paper describes the development and the wind tunnel test of a variable geometry morphing airfoil using corrugated structures. Proof-of-concept study of a morphing wing with corrugated flexible seamless flap-like structure is verified by finite element analysis, and a prototype is manufactured using carbon fiber reinforced plastics. For the actuation system, two servomotors are installed inside the prototype wing to control the airfoil shape by the chordwise tension of the connected wires. Successful actuation of the prototype wing is demonstrated under the air speed up to 30 m/s in the wind tunnel test. Basic aerodynamic properties are also evaluated in comparison to traditional airfoil with a hinged control surface. Lift increase of variable corrugated wing is recognized compared to the traditional wing when the aileron angle increases.
103 citations
TL;DR: In this article, a leading-edge protuberance method was used to modify the flow pattern of the airfoil boundary layer through chordwise and spanwise evolutions of the interacting streamwise vortices generated by protuberances, where the separation of the turbulent boundary layer dominated within the stall region and the rather strong attachment of the laminar boundary layer still existed within the post-stall region.
Abstract: An experimental study of flow separation control on a low-Re
c airfoil was presently investigated using a newly developed leading-edge protuberance method, motivated by the improvement in the hydrodynamics of the giant humpback whale through its pectoral flippers. Deploying this method, the control effectiveness of the airfoil aerodynamics was fully evaluated using a three-component force balance, leading to an effectively impaired stall phenomenon and great improvement in the performances within the wide post-stall angle range (22°–80°). To understand the flow physics behind, the vorticity field, velocity field and boundary layer flow field over the airfoil suction side were examined using a particle image velocimetry and an oil-flow surface visualization system. It was found that the leading-edge protuberance method, more like low-profile vortex generator, effectively modified the flow pattern of the airfoil boundary layer through the chordwise and spanwise evolutions of the interacting streamwise vortices generated by protuberances, where the separation of the turbulent boundary layer dominated within the stall region and the rather strong attachment of the laminar boundary layer still existed within the post-stall region. The characteristics to manipulate the flow separation mode of the original airfoil indicated the possibility to further optimize the control performance by reasonably designing the layout of the protuberances.
97 citations
16 Jun 2014
TL;DR: Aeroacoustic measurements associated with noise radiation from the leading edge slat of the canonical, unswept 30P30N three-element high-lift airfoil configuration have been obtained in a 2 m x 2 m hard-wall wind tunnel at the Japan Aerospace Exploration Agency (JAXA) as discussed by the authors.
Abstract: Aeroacoustic measurements associated with noise radiation from the leading edge slat of the canonical, unswept 30P30N three-element high-lift airfoil configuration have been obtained in a 2 m x 2 m hard-wall wind tunnel at the Japan Aerospace Exploration Agency (JAXA). Performed as part of a collaborative effort on airframe noise between JAXA and the National Aeronautics and Space Administration (NASA), the model geometry and majority of instrumentation details are identical to a NASA model with the exception of a larger span. For an angle of attack up to 10 degrees, the mean surface Cp distributions agree well with free-air computational fluid dynamics predictions corresponding to a corrected angle of attack. After employing suitable acoustic treatment for the brackets and end-wall effects, an approximately 2D noise source map is obtained from microphone array measurements, thus supporting the feasibility of generating a measurement database that can be used for comparison with free-air numerical simulations. Both surface pressure spectra obtained via KuliteTM transducers and the acoustic spectra derived from microphone array measurements display a mixture of a broad band component and narrow-band peaks (NBPs), both of which are most intense at the lower angles of attack and become progressively weaker as the angle of attack is increased. The NBPs exhibit a substantially higher spanwise coherence in comparison to the broadband portion of the spectrum and, hence, confirm the trends observed in previous numerical simulations. Somewhat surprisingly, measurements show that the presence of trip dots between the stagnation point and slat cusp enhances the NBP levels rather than mitigating them as found in a previous experiment.
TL;DR: In this paper, wind-tunnel experiments were conducted to quantify the effectiveness of ac and nanosecond-pulse single dielectric barrier discharge plasma actuators to suppress leading-edge stall on a NASA Energy Efficient Transport airfoil at Mach numbers up to 0.4 and chord Reynolds number up to 2.3×106.
Abstract: Wind-tunnel experiments were conducted to quantify the effectiveness of ac and nanosecond-pulse single dielectric barrier discharge plasma actuators to suppress leading-edge stall on a NASA Energy Efficient Transport airfoil at Mach numbers up to 0.4 and chord Reynolds numbers up to 2.3×106. The airfoil model was designed to have a removable leading edge to accommodate two different leading-edge plasma-actuator designs, either with a thick ceramic or a thin Kapton dielectric layer. The exposed electrode for both plasma actuators was located at the leading edge of the airfoil. The covered electrode for both was on the suction side of the leading edge. The model was mounted on stages that measured the lift and drag forces and the pitching moment about the quarter-chord location. Both steady and unsteady ac plasma-actuator operation were examined. By its nature, the nanosecond-pulse plasma actuator only operates in unsteady operation. The optimal unsteady frequencies with regard to lift, lift to drag, and pi...
TL;DR: In this article, the authors use a Computational Blade Optimization and Load Deflation Tool (CoBOLDT) to investigate the three extreme point designs obtained from a multi-objective optimisation of turbine thrust, annual energy production as well as mass for a horizontal axis wind turbine blade.
TL;DR: In this article, a quasi-steady, linear dependence on the history of input disturbances, provided that small-amplitude bounds are observed, is explored for the problem of periodic sinusoidal streamwise gusts, by comparing experiments on nominally 2D airfoils.
Abstract: Airfoil aerodynamic loads are expected to have quasi-steady, linear dependence on the history of input disturbances, provided that small-amplitude bounds are observed. We explore this assertion for the problem of periodic sinusoidal streamwise gusts, by comparing experiments on nominally 2D airfoils in temporally sinusoidal modulation of freestream speed in a wind tunnel vs. sinusoidal displacement of the airfoil in constant freestream in a water tunnel. In the wind tunnel, there is a streamwise unsteady pressure gradient causing a buoyancy force, while in the water tunnel one must subtract the inertial load of the test article. Both experiments have an added-mass contribution to aerodynamic force. Within measurement resolution, lift and drag, fluctuating and mean, were in good agreement between the two facilities. For incidence angle below static stall, small-disturbance theory was found to be in good agreement with measured lift history, regardless of oscillation frequency. The circulatory component of fluctuating drag was found to be independent of oscillation frequency. For larger incidence angles, there is marked departure between the measured lift history and that predicted from Greenberg's formula. Flow visualization shows coupling between bluff-body shedding and motion-induced shedding, identifiable with lift cancellation or augmentation, depending on the reduced frequency. Isolating the buoyancy effect in the wind tunnel and dynamic tares in the water tunnel, and theoretical calculation of apparent-mass in both cases, we arrive at good agreement in measured circulatory contribution between the two experiments whether the flow is attached or separated substantiating the linear superposition of the various constituents to total lift and drag, and supporting the idea that aerodynamic gust response can legitimately be studied in a steady freestream by oscillating the test article.
TL;DR: In this article, an analysis to estimate the aerodynamic drag of the train is performed using Computational Fluid Dynamics (CFD) for the Great Train eXpress (GTX).
TL;DR: In this paper, the impact of blade roughness and biofouling on the performance of a two-bladed horizontal axis marine current turbine was investigated experimentally and numerically.
TL;DR: In this paper, a reduced-order state-space model for a pitching and plunging airfoil is presented, which includes multiple inputs (pitch, plunge, and surge) and explicit parameterization by the pitch-axis location.
16 Jun 2014
TL;DR: In this paper, a set of airfoils with porous trailing edges of varying chordwise extent were evaluated in an open jet wind tunnel, using a microphone array measurement technique and a deconvolution beamforming algorithm.
Abstract: The use of porous trailing edges is one possible approach to reduce airfoil trailing edge noise. Past experiments on fully porous airfoil models showed that a noticeable noise reduction can be achieved. However, this reduction is accompanied by a loss in aerodynamic performance. To combine the acoustic advantages of the porous trailing edge with the aerodynamic advantages of a non-porous airfoil, the generation of trailing edge noise of airfoil models that only have a porous trailing edge is investigated. To this end, initial experiments were performed on a set of airfoils with porous trailing edges of varying chordwise extent in an open jet wind tunnel, using microphone array measurement technique and a deconvolution beamforming algorithm. The lift forces and drag forces were measured simultaneously to the acoustic measurements. Additionally, hot-wire measurements were performed to allow conclusions on the underlying mechanisms that enable the noise reduction. It could be demonstrated that, depending on the porous material, airfoils that are non-porous except for their trailing edge can still lead to a noticeable trailing edge noise reduction, while providing a better aerodynamic performance.
TL;DR: In this paper, the TNO model is modified by introducing anisotropy in the definition of the turbulent vertical velocity spectrum across the boundary layer and by considering a frequency-dependent vertical correlation length.
TL;DR: In this paper, an innovative optimization process for airfoil geometry design is introduced, based on the coupling of a PARSEC parameterization for shape and a GA optimization method to find Nash equilibria.
TL;DR: In this paper, evidence is presented for the existence of multiple solutions of the Reynolds-averaged Navier-Stokes equations with the one-equation Spalart-Allmaras and twoequation Wilcox k-ω turbulence models on fixed grids in three dimensions.
Abstract: In this paper, evidence is presented for the existence of multiple solutions of Reynolds-averaged Navier–Stokes equations with the one-equation Spalart–Allmaras and two-equation Wilcox k-ω turbulence models on fixed grids in three dimensions and how they were obtained is described. The two major configurations considered are an “academic” extruded two-dimensional airfoil geometry and the trap wing test case. The observed appearance of the multiple solutions seems to be closely related to smooth body separation (sometimes massive) routinely observed in flows over high-lift configurations, especially near stall angles of attack. The results are obtained and cross-verified with two stabilized finite-element codes (streamwise upwind Petrov–Galerkin), which provide residual converged results for complex flows with second-order discretizations. In the paper, the ways multiple solutions have been obtained are described, including such obvious ones as providing a different initial guess to the steady-state solver...
16 Jun 2014
TL;DR: In this article, a dual-rotor wind turbine (DRWT) concept is proposed that aims at mitigating the aerodynamic inefficiencies in the blade root region (near the hub) due to several non-aerodynamic constraints.
Abstract: Horizontal axis wind turbines suer from aerodynamic ineciencies in the blade root region (near the hub) due to several non-aerodynamic constraints. Aerodynamic interactions between turbines in a wind farm also lead to signicant loss of wind farm eciency. A new dual-rotor wind turbine (DRWT) concept is proposed that aims at mitigating these two losses. A DRWT is designed that uses an existing turbine rotor for the main rotor, while the secondary rotor is designed using a high lift-to-drag ratio airfoil. Reynolds Averaged Navier- Stokes computational uid dynamics simulations are used to optimize the design. Large eddy simulations conrm the increase energy capture potential of the DRWT. Wake comparisons however do not show enhanced entrainment of axial momentum.
TL;DR: In this paper, the azimuthally averaged velocity is used as the sectional velocity to define the angle of attack and the coefficient of lift and drag is determined by the forces on the blade.
16 Jun 2014
TL;DR: In this paper, the effect of various Variable Camber Continuous Trailing Edge Flap (VCCTEF) configurations on the lift and drag of a NASA Generic Transport Model (GTM) wing section at a span-wise location called the break station was explored.
Abstract: This paper reports the results of a computational study that was conducted to explore the effect of various Variable Camber Continuous Trailing Edge Flap (VCCTEF) configurations on the lift and drag of a NASA Generic Transport Model (GTM) wing section at a span-wise location called the break station that marks a sharp change in the wing trailing edge slope. The OVERFLOW solver with the the one-equation SpalartAllmaras (SA) turbulence model and the two-equation (k − ω) Shear Stress Transport (SST) turbulence model was first applied to a NACA0021 airfoil case and the results were compared with experimental data of Harris and ARC2D results. The comparison showed good agreement between earlier results and the SA model. Therefore, SA model was used for all the simulations in this study. Design cruise condition at 36,000 feet at free stream Mach number of 0.797 and Reynolds number of 30.734x10 was simulated for an angle of attack (AoA) sweep from -3 deg. to 10 deg. Five VCCTEF configurations with varying camber in the flap region were considered along with an unmodified (no flap deflection) airfoil as the baseline case. Comparison of lift and drag corresponding to these configurations with baseline configuration (retracted flaps) showed a definite trend in the results. Although the baseline configuration produced the lowest lift at a given AoA among the set under investigation, it produces stall after about 5 deg AoA, whereas with the VCCTEF settings, stall occurs earlier between 3 and 4 deg AoA. The lift enhancement was significant with the extended flaps, but it was accompanied with a drag penalty, as expected. But, the lift versus drag L/D results showed that at the design cruise lift coefficient of 0.51, the L/D characteristics improved from the baseline to four of the five VCCTEF configurations. Among these four configurations, the configuration which reflects a parabolic-like camber is more optimal than the other three configurations in terms of improved L/D and well-behaved Cp distribution. The lift prediction is compared against theoretical lift prediction from potential flow theory. Excellent agreement between computed and theoretical incremental lift is shown.
TL;DR: In this article, the effects of jet width on blowing and suction flow control were evaluated for a NACA 0012 airfoil, and the results showed that when the blowing jet width increases, the lift-to-drag ratio rises continuously in tangential blowing and decreases quasi-linearly in perpendicular blowing.
Abstract: The effects of jet width on blowing and suction flow control were evaluated for a NACA 0012 airfoil. RANS equations were employed in conjunction with a Menter’s shear stress turbulent model. Tangential and perpendicular blowing at the trailing edge and perpendicular suction at the leading edge were applied on the airfoil upper surface. The jet widths were varied from 1.5% to 4% of the chord length, and the jet velocity was 0.3 and 0.5 of the free-stream velocity. Results of this study demonstrated that when the blowing jet width increases, the lift-to-drag ratio rises continuously in tangential blowing and decreases quasi-linearly in perpendicular blowing. The jet widths of 3.5% and 4% of the chord length are the most effective amounts for tangential blowing, and smaller jet widths are more effective for perpendicular blowing. The lift-to-drag ratio improves when the suction jet width increases and reaches its maximum value at 2.5% of the chord length.
TL;DR: In this paper, a high performance Ishii airfoil was analyzed using both a wind-tunnel and large-eddy simulations at a low-Reynolds-number condition (Re=23,000).
Abstract: A high-performance Ishii airfoil was analyzed using both a wind-tunnel and large-eddy simulations at a low-Reynolds-number condition (Re=23,000). The design guidelines for an airfoil shape with a high lift-to-drag ratio under the aforementioned condition are described by analyses of flowfields and aerodynamic characteristics of the Ishii airfoil. Compared with conventional airfoils, such as the NACA 0012 and NACA 0002, the shape characteristic effects of the Ishii airfoil on its flowfield and aerodynamic characteristics are discussed. The shape on the suction side of the Ishii airfoil can cause delays in the flow separation at low angle of attacks. The separated flow reattaches, and a separation bubble forms even when trailing-edge separation changes to leading-edge separation. The separation bubble contributes to an increase in lift coefficient. In addition, the Ishii airfoil can gain a high positive pressure on the pressure side as compared with the other two symmetric airfoils due to the camber near th...
TL;DR: In this article, the authors used the angle of attack, Reynolds number, riblet size, and location of the riblets to determine the optimal position for reducing the drag of the airfoil.
Abstract: sections of the airfoil in order to determine the optimal riblet location in terms of drag reduction. Results showed that the magnitude of drag reduction depended on the angle of attack, Reynolds number, riblet size, and riblet location. For some congurations, riblets produced signicant drag reduction of up to 5%, while for others riblets were detrimental. Trends in the results indicated an optimum riblet size of 62- m for the range of Reynolds numbers at which tests were conducted. The airfoil chord was 18 in (0.457 m). Results also showed that each riblet size performed best at a given Reynolds number with the optimal Reynolds number decreasing with an increase in riblet size.
TL;DR: In this article, a number of airfoils have been tested in the Pennsylvania State University low-speed low-turbulence wind tunnel, and the results of these tests are compared with those predicted using several well-known theoretical methods.
Abstract: A number of airfoils have been tested in the Pennsylvania State University low-speed low-turbulence wind tunnel, and the results of these tests are compared with those predicted using several well-known theoretical methods. The theoretical methods used are the potential-flow/integral boundary-layer methods XFOIL 6.96 and PROFIL07 and the Reynolds-averaged Navier–Stokes solver OVERFLOW 2.2e. This version of the OVERFLOW solver contains an implementation of the transitional shear-stress transport turbulence model developed by Langtry and Menter (“Correlation-Based Transition Modeling for Unstructured Parallelized Computational Fluid Dynamics Codes,” AIAA Journal, Vol. 47, No. 12, 2009, pp. 2894–2906). This model is capable of capturing the influence of transition on the flowfield through a local-correlation method. The airfoils considered for this study are the E 387, S805, PSU 94-097, HTR1555, S903, and S824. Although none of the theoretical methods considered were consistently the best overall, all codes ...
TL;DR: In this paper, a corrugated foil behavior is investigated experimentally as well as theoretically by compressing the foil, between two parallel surfaces, both statically and dynamically, to obtain hysteresis curves.
TL;DR: In this article, the effect of a low Reynolds number in the range of 2.0 × 10 4 Re c 5.0 on the aerodynamic characteristics of a pitching NACA0012 airfoil was investigated.