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1
Tomasz Lusiak, Andrej Novak, Martin Bugaj, and Radovan Madlenak. "Assessment of Impact of Aerodynamic Loads on the Stability and Control of the Gyrocopter Model." Communications - Scientific letters of the University of Zilina 22, no. 4 (October 1, 2020): 63–69. http://dx.doi.org/10.26552/com.c.2020.4.63-69.
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Aerodynamic modelling currently relates to development of mathematical models to describe the aerodynamic forces and moments acting on the aircraft. It is a challenging part of aerodynamics that defines a comprehensive approach to using traditional methods and modern techniques to obtain relevant data. The most complicated task for the aerodynamics and flight dynamics is definition, computation and quantification of the aerodynamic description of an object. This paper presents how to determine the aerodynamic load on a gyrocopter and defines the effect on its stability and control. The first step to solution is to develop simpler approximate aerodynamic model - a model that can be used in analysis of aerodynamic load and can represent the aerodynamic properties of the gyrocopter with an acceptable degree of accuracy. Control and stability are very important parts of aircraft characteristics and therefore those characteristics were analyzed in simulation. Finally, the aerodynamic data outputs are assessed in terms of impact of aerodynamic loads on stability and control of the gyrocopter model.
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Enciu, K., and A. Rosen. "Aerodynamic modelling of fin stabilised underslung loads." Aeronautical Journal 119, no. 1219 (September 2015): 1073–103. http://dx.doi.org/10.1017/s0001924000011143.
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AbstractBox-like slung loads exhibit periodic yaw response instabilities, while carried externally by a helicopter. When coupled with the slung load longitudinal and lateral pendulum motions, these instabilities result in significant pendulum oscillations of the load. High amplitude oscillations lead in many cases to the limiting of a load’s flight envelope. Using wind tunnel and flight tests, rear mounted fins were previously demonstrated as efficient means for stabilisation of a problematic load. However, the lack of a proper analytical model of the stabilised load’s aerodynamic characteristics, led to a trial and error development process, without an appropriate physical understanding of the stabilisation problem. The present paper describes a method for the aerodynamic modeling of fins stabilised slung loads based on a limited number of simple static wind-tunnel tests. The resulting database is incorporated in a dynamical slung load simulation that shows good agreement with dynamic wind-tunnel tests. The applicability of the proposed method is demonstrated, by the calculation of stabilised loads aerodynamic databases for interim fin inclination angles not covered by tests.
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Abhilash and Joseph Jikhil. "Building Aerodynamics and Shape Optimisation." Journal of Sustainable Construction Engineering and Project Management 6, no. 2 (May 15, 2023): 1–16. https://doi.org/10.5281/zenodo.7935492.
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<em>This study is based on the topic building aerodynamics and shape optimization. Usually, the aerodynamic considerations are not taken into account while designing the external shape and orientation of building. The main considerations are architectural considerations, functional requirements and site limitations. As a result, the structures become bluff bodies with strong wind-structure interaction produced loads. These can be reduced by using aerodynamic mitigation techniques and shape optimization procedure. This report reviews the old/recent work on aerodynamic mitigation techniques evolved for diminishing the wind loads on buildings by modifying their shape and/or adding some simple architectural elements. This research examines aerodynamic mitigating solutions for both low-rise and high-rise structures. Aerodynamic shape optimization techniques for tall buildings for reducing the wind load are also included and the suitability and challenges of using Computational Fluid Dynamics (CFD) for this application were discussed. Gradient based methods and non-gradient based methods are the overview of optimization techniques. This report will surely help in using the aerodynamic shape and consideration of the structures’ shape, in terms of wind performance, early in the design process. This report also helps in using various techniques that can be used for reducing wind loads on buildings.</em>
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Perez-Becker, Sebastian, Francesco Papi, Joseph Saverin, David Marten, Alessandro Bianchini, and Christian Oliver Paschereit. "Is the Blade Element Momentum theory overestimating wind turbine loads? – An aeroelastic comparison between OpenFAST's AeroDyn and QBlade's Lifting-Line Free Vortex Wake method." Wind Energy Science 5, no. 2 (June 15, 2020): 721–43. http://dx.doi.org/10.5194/wes-5-721-2020.
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Abstract. Load calculations play a key role in determining the design loads of different wind turbine components. To obtain the aerodynamic loads for these calculations, the industry relies heavily on the Blade Element Momentum (BEM) theory. BEM methods use several engineering correction models to capture the aerodynamic phenomena present in Design Load Cases (DLCs) with turbulent wind. Because of this, BEM methods can overestimate aerodynamic loads under challenging conditions when compared to higher-order aerodynamic methods – such as the Lifting-Line Free Vortex Wake (LLFVW) method – leading to unnecessarily high design loads and component costs. In this paper, we give a quantitative answer to the question of load overestimation of a particular BEM implementation by comparing the results of aeroelastic load calculations done with the BEM-based OpenFAST code and the QBlade code, which uses a particular implementation of the LLFVW method. We compare extreme and fatigue load predictions from both codes using sixty-six 10 min load simulations of the Danish Technical University (DTU) 10 MW Reference Wind Turbine according to the IEC 61400-1 power production DLC group. Results from both codes show differences in fatigue and extreme load estimations for the considered sensors of the turbine. LLFVW simulations predict 9 % lower lifetime damage equivalent loads (DELs) for the out-of-plane blade root and the tower base fore–aft bending moments compared to BEM simulations. The results also show that lifetime DELs for the yaw-bearing tilt and yaw moments are 3 % and 4 % lower when calculated with the LLFVW code. An ultimate state analysis shows that extreme loads of the blade root out-of-plane bending moment predicted by the LLFVW simulations are 3 % lower than the moments predicted by BEM simulations. For the maximum tower base fore–aft bending moment, the LLFVW simulations predict an increase of 2 %. Further analysis reveals that there are two main contributors to these load differences. The first is the different way both codes treat the effect of the nonuniform wind field on the local blade aerodynamics. The second is the higher average aerodynamic torque in the LLFVW simulations. It influences the transition between operating modes of the controller and changes the aeroelastic behavior of the turbine, thus affecting the loads.
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Tian, Xiao, Wenhui Yan, and Kun Zhang. "Numerical Calculation of 1P Aerodynamic Loads on Aviation Propellers." Journal of Physics: Conference Series 2747, no. 1 (May 1, 2024): 012043. http://dx.doi.org/10.1088/1742-6596/2747/1/012043.
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Abstract To accurately predict the 1P aerodynamic loads of aviation propellers, this paper established a mathematical model of aviation propeller 1P aerodynamic loads based on the coupling method of blade element theory and momentum theory. Correction methods such as the Prandtl tip correction method and the propeller root correction method were implemented to further improve calculation accuracy. A 1P aerodynamic load calculation procedure was developed based on the mathematical model by using the Matlab software. 1P aerodynamic loads of a three-blade propeller were predicted for three different angles including 3 °, 9 °, and 12°. The numerical calculation results show that the calculated aerodynamic characteristic parameters of individual propeller blades obtained based on the propeller 1P aerodynamic load mathematical model deviate less than 6% from the CFD simulation results, and regular periodic pulsations are observed. The numerical calculations in this paper show that the propeller 1P aerodynamic load calculation procedure developed based on this model can accurately predict the propeller 1P aerodynamic load, which can provide some reference for the study of aviation propeller aerodynamic characteristics.
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Jiao, Shuaike, and Jiahong Zheng. "Aerodynamics Analysis of Helicopter Rotor in Flight Test Using Strain Gauge Sensors." Sensors 25, no. 6 (March 19, 2025): 1911. https://doi.org/10.3390/s25061911.
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The acquisition of aerodynamic loads on helicopter rotors is fundamental to the study of helicopter performance optimization, structural design, flight control, and other aspects. However, at present, aerodynamic loads on rotors are primarily obtained through theoretical calculations, simulation analysis, and wind tunnel tests, with few reports on flight measurements. This paper proposes a method for obtaining helicopter rotor aerodynamic loads by flapping moment measurements in flight with strain gauge sensors. First, strain gauge sensors are installed at different cross-sectional positions on the rotor blades to measure strain during flight. Then, the strains are incorporated into the blade flapping motion equations to establish the relationship between rotor aerodynamic loads and flapping moment. Finally, the aerodynamic loads on the rotor are calculated by the relationship. This method can provide more accurate load calculation results compared to simulation computations and wind tunnel tests. In this paper, the distribution patterns of rotor aerodynamic loads were investigated, which aligned with theoretical analysis and can offer valuable insights for blade design optimization.
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Li, Tian, Yifan Li, Lai Wei, and Jiye Zhang. "Study on Lateral Vibration of Tail Coach for High-Speed Train under Unsteady Aerodynamic Loads." Vibration 6, no. 4 (December 8, 2023): 1048–59. http://dx.doi.org/10.3390/vibration6040061.
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As the speed of high-speed trains increases, the vehicle’s lateral stability steadily deteriorates. There have been observations of abnormal vibrations in the tail car, particularly on certain sections of the railway line. This study built a high-speed train aerodynamic simulation model for a three-car consist, and a multibody dynamics simulation model for an eight-car consist based on numerical simulations of train aerodynamics and multibody dynamics. It investigated both steady and unsteady aerodynamic loads, flow field characteristics, and the dynamic performance of vehicles under varied aerodynamic loads at 400 km/h. The results indicate that the aerodynamic loads generated during high-speed train operation exhibit highly unsteady characteristics. Steady aerodynamic loads have a relatively minor impact on the vehicle’s dynamic performance, whereas unsteady loads exert a more significant influence. Under unsteady aerodynamic forces, the tail car experiences severe lateral vibrations. The lateral stability index, displacement, velocity, and acceleration of the tail car under unsteady conditions were measured at 2.26, 7.54 mm, and 0.53 m/s2, respectively. These values represent increases of over 17.71%, 148.84%, and 111.24%, respectively, compared to the steady loads. Large oscillation amplitudes result in more significant lateral displacements and accelerations of the vehicle. This phenomenon is a crucial factor contributing to the “tail swing” effect observed in high-speed trains. This study emphasizes the importance of considering unsteady aerodynamic effects in assessing the lateral stability of high-speed trains and highlights the significance of mitigating the adverse impacts of such dynamic responses, particularly in the tail car.
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Zhang, Xuyao, Congxin Yang, and Shoutu Li. "Influence of the Heights of Low-Level Jets on Power and Aerodynamic Loads of a Horizontal Axis Wind Turbine Rotor." Atmosphere 10, no. 3 (March 11, 2019): 132. http://dx.doi.org/10.3390/atmos10030132.
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The influence of the heights of low-level jets (LLJs) on the rotor power and aerodynamic loads of a horizontal axis wind turbine were investigated using the fatigue, aerodynamics, structures, and turbulence code. The LLJ and shear inflow wind fields were generated using an existing wind speed spectral model. We found that the rotor power predicted by the average wind speed of the hub height is higher than the actual power in relatively weak and shallow LLJ inflow conditions, especially when the LLJ height is located inside the rotor-swept area. In terms of aerodynamic loads, when the LLJ height is located inside the rotor-swept area, the root mean square (RMS) rotor thrust coefficient and torque coefficient increase, while the RMS rotor unbalanced aerodynamic load coefficients, including lateral force, longitudinal force, tilt moment, and yaw moment, decreased. This means that the presence of both positive and negative wind shear in the rotor-swept area not only increases the rotor power but also reduces the unbalanced aerodynamic loads, which is beneficial to the operation of wind turbine. Power spectrum analysis shows no obvious difference in the power spectrum characteristics of the rotor torque and thrust in LLJ inflow conditions with different heights.
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Xiang, Xiao Jun, and Yu Qian. "Numerical Simulation of Unsteady Aerodynamic Loads over an Aircraft." Advanced Materials Research 908 (March 2014): 264–68. http://dx.doi.org/10.4028/www.scientific.net/amr.908.264.
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The unsteady aerodynamic loads are the basic of the aeroelastic. This paper focuses on the computation of the unsteady aerodynamic loads for forced periodic motions under different Mach numbers. The flow is modeled using the Euler equations and an unsteady time-domain solver is used for the computation of aerodynamic loads for forced periodic motions. The Euler equations are discretized on curvilinear multi-block body conforming girds using a cell-centred finite volume method. The implicit dual-time method proposed by Jameson is used for time-accurate calculations. Rigid body motions were treated by moving the mesh rigidly in response to the applied sinusoidal motion. For an aircraft model, a validation of the unsteady aerodynamics loads is first considered. Furthermore, a study for understanding the influence of different Mach number was conducted. A reverse of the trend of hysteretic loops can be observed with the increasing of the Mach number.
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Anil, Mary, and Deepa Varkey. "Recent Progress in Aerodynamics for Aeroelastic Analysis." International Journal for Research in Applied Science and Engineering Technology 10, no. 6 (June 30, 2022): 2890–93. http://dx.doi.org/10.22214/ijraset.2022.44475.
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Abstract: Aerodynamics has gained considerable popularity in the aerospace industry. Based on the characteristics of a structure, aerodynamic behavior varies from structure to structure. A reliable aeroelastic analysis requires accurate capture of aerodynamic forces. To produce accurate aerodynamic loads, it is necessary to develop an appropriate aerodynamic model. A review of various approaches to aerodynamic modeling for aeroelastic analysis of diverse wing configurations is presented in this paper. The study covers a wide range of finite element software platforms used in the aeroelastic analysis in various flow regimes.
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Li, Yun Feng. "Loads Calculation of Pitch Bearing of Wind Turbine." Advanced Materials Research 148-149 (October 2010): 479–84. http://dx.doi.org/10.4028/www.scientific.net/amr.148-149.479.
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Loads calculation process for pitch bearing of wind turbine was presented. The aerodynamic of the rotor was analyzed by using momentum theory and blade element theory firstly; then the aerodynamic loads, the gravitational loads and the centrifugal loads of the pitch bearing were calculated along each axis of the bearing coordinate system; thirdly, all the loads of each direction of the pitch bearing load were composed into three loads, they are radial, axial and tilting moment loads. A calculation example was given at last.
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He, Pan, and Jian Xia. "Study on the Influence of Low-Level Jet on the Aerodynamic Characteristics of Horizontal Axis Wind Turbine Rotor Based on the Aerodynamics–Controller Interaction Method." Energies 15, no. 8 (April 7, 2022): 2709. http://dx.doi.org/10.3390/en15082709.
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Accurate prediction of the aerodynamic characteristics of wind rotors subjected to various wind profiles is of considerable importance in the aerodynamics and structural design of wind turbines. As a very complex atmospheric phenomenon, the impact of a low-level jet (LLJ) on the aerodynamic characteristics of wind rotors is becoming more and more significant with the increase in wind turbine height. Additionally, during calculating the aerodynamic characteristics of the wind rotor, the known wind speed, rotor speed, and blade-pitch angle are generally required. However, when the wind profile is in the LLJ condition, it is difficult to determine the blade-pitch angle and rotor speed. Therefore, in this paper, the blade-element-momentum (BEM) method is exploited by considering the coupling with the generator-torque controller and blade-pitch controller. In order to solve the problem of the unknown rotor speed and blade-pitch angle under the LLJ condition, a C++ code is developed. Then, the influence of the LLJ on the aerodynamic characteristics of the wind rotor is exclusively examined. The research results show that the calculation method can precisely evaluate the rotor speed, blade-pitch angle, and aerodynamic characteristics of the wind rotor. The influence of the LLJ on the aerodynamic loads of the wind rotor is greater than that of the wind shear. When the LLJ is placed inside the rotor swept area, the aerodynamic loads of the blade exhibit two local maximums and local minimums with the variation of the azimuth angle in a rotation period. The closer the LLJ height is to the hub height, the greater the average aerodynamic loads of the wind rotor are, and the smaller the amplitude of aerodynamic loads of the blade is relative to the average value. When the LLJ height is positioned outside the rotor swept area, the change law of the aerodynamic loads of the blade would be similar to that of the wind subjected to a very strong wind shear inflow. This study provides a crucial reference for a more rational assessment of the aerodynamic characteristics of wind turbines under the action of complex wind profiles, as well as revealing the influence of the LLJ on the aerodynamic characteristics of wind turbines.
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Liu, Jun, Zhengqi Gu, Taiming Huang, Shuya Li, Ledian Zheng, and Kai Sun. "Coupled analysis of the unsteady aerodynamics and multi-body dynamics of a small car overtaking a coach." Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering 233, no. 14 (February 22, 2019): 3684–99. http://dx.doi.org/10.1177/0954407019831559.
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The severe additional aerodynamic loads that are generated on a small car when overtaking a coach have an adverse effect on the car handling stability and its safety. In this article, a two-way coupling of the unsteady aerodynamics and multi-body dynamics is performed in order to study the mutual interactions of a car in an overtaking maneuver with a coach. The unsteady aerodynamic interactions are obtained by using SST (Menter) K-Omega Detached Eddy Simulation and overset mesh technology. The aerodynamics couple the multi-body dynamics, taking into account the effects of the transverse spacing and the cross winds. To validate the necessity of the two-way coupling method, a one-way coupling of the aerodynamics to the vehicle motion is also conducted. Finally, by comparing the aerodynamic loads and the dynamic response of the overtaking car in different overtaking maneuvers between one- and two-way coupling, the results show that it should be considered with two-way coupling analyses of the car while overtaking a coach, particularly under the severe conditions of a lower transverse spacing or the crosswinds.
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Zeng, Xiaohui, Han Wu, Jiang Lai, and Hongzhi Sheng. "Hunting stability of high-speed railway vehicles on a curved track considering the effects of steady aerodynamic loads." Journal of Vibration and Control 22, no. 20 (August 9, 2016): 4159–75. http://dx.doi.org/10.1177/1077546315571986.
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Aerodynamic loads may have effects on the hunting stability, and the factor of curved track makes it more complicated. Therefore, considering the steady aerodynamic loads generated by crosswind and airflow in the opposite advancing direction of train, the hunting stability of high-speed railway vehicle on a curved track is studied in this paper. The changes of gravitational restoring force and creep coefficients which are caused by aerodynamic loads are considered, and the change of equilibrium position due to aerodynamic loads, centrifugal force and the factor of curved track is also in consideration. A mathematical model of a high-speed railway vehicle during curve negotiation with aerodynamic loads is set up. A program based on the model is written and verified. Using this program, the linear critical speed considering the effects of aerodynamic loads is determined by the eigenvalue analysis. This paper investigates the critical speeds in three aerodynamic conditions. Considering the aerodynamic loads, the dependence of critical speed on curve radius and super-elevation is analyzed, and the impact of aerodynamic loads on instability mode is analyzed as well. In addition, this paper obtains the dominant factors affecting critical speed and the variation tendency of critical speed with primary longitudinal stiffness by orthogonal experiments. The results show that the critical speed decreases or increases while the wind is blowing to outer rail or inner rail respectively. The aerodynamic loads produce obvious effects on the instability mode. The variation tendency of critical speed dependence on curve radius in the conditions with aerodynamic loads keeps consistent with the case without aerodynamic loads. It is seen from the orthogonal experiments that, aerodynamic loads and curve radius are the dominant factors affecting linear critical speed of vehicle on a curved track, and the linear critical speed decreases with the increasing of primary longitudinal stiffness.
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Srivastava, Nilabh, Peter T. Tkacik, and Russell G. Keanini. "Ascending rockets as macroscopic self-propelled Brownian oscillators." Proceedings of the Royal Society A: Mathematical, Physical and Engineering Sciences 468, no. 2148 (September 12, 2012): 3965–94. http://dx.doi.org/10.1098/rspa.2012.0273.
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High-fidelity numerical experiments and theoretical modelling are used to study the dynamics of a sounding-rocket-scale rocket, subject to altitude-dependent random wind and nozzle side loads and deterministic aerodynamic loading. This paper completes a series of studies that showed that Ornstein–Uhlenbeck (OU) rotational dynamics arise when random nozzle side loads dominate wind and aerodynamic loading. In contrast to the earlier work, this paper elucidates that under conditions where aerodynamic, wind and nozzle side loads are comparable, the rocket behaves as stochastic Brownian oscillator. The Brownian oscillator model allows straightforward interpretation of the complex rotational dynamics observed: three dynamical regimes—each characterized by differing balances between nozzle-side-load-induced torques, spring-like aerodynamic torques and mass flux damping torques—characterize rocket ascent. Further, the paper illuminates that in the limit where wind and aerodynamic loads are small, random mass flux variations exponentially amplify side-load-induced rotational stochasticity. In this practical limit, pitch/yaw dynamics are described by a randomly damped OU process; an exact solution of the associated Fokker–Planck equation can be obtained and used to compute, e.g. time-dependent pitch/yaw rate means and variances.
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Lai, Yung-Cheng (Rex), and Christopher P. L. Barkan. "Options for Improving the Energy Efficiency of Intermodal Freight Trains." Transportation Research Record: Journal of the Transportation Research Board 1916, no. 1 (January 2005): 47–55. http://dx.doi.org/10.1177/0361198105191600108.
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Intermodal trains are typically the fastest trains operated by North American freight railroads. Ironically, these trains tend to have the poorest aerodynamic characteristics. Because of constraints imposed by equipment design and diversity, intermodal trains incur greater aerodynamic penalties and increased fuel consumption than other trains. Improving the loading patterns of intermodal trains has the potential to improve aerodynamic characteristics and thus fuel efficiency. Train aerodynamics and resistance analyses were conducted on several alternative intermodal train-loading configurations. Matching intermodal loads with cars of an appropriate length reduces the gap length between loads and thereby improves airflow. Filling empty slots with empty containers or trailers also reduces aerodynamic resistance and improves energy efficiency, despite the additional weight penalty and consequent increase in bearing and rolling resistance. Depending on the particular train configuration, train resistance can be lowered by as much as 27% and fuel savings by 1 gal/mi per train.
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Qian, Yu, Jun Li Yang, Xiao Jun Xiang, and Ming Qiang Chen. "Numerical Simulation of Unsteady Aerodynamic Loads over an Aerofoil in Transonic Flow." Advanced Materials Research 644 (January 2013): 275–78. http://dx.doi.org/10.4028/www.scientific.net/amr.644.275.
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The unsteady aerodynamic loads are the basic of the aeroelasitc. This paper focuses on the computation of the unsteady aerodynamic loads for forced periodic motions under high subsonic Mach numbers. The flow is modeled using the Euler equations and an unsteady time-domain solver is used for the computation of aerodynamic loads for forced periodic motions. The Euler equations are discretized on curvilinear multi-block body conforming girds using a cell-centred finite volume method. The implicit dual-time method proposed by Jameson is used for time-accurate calculations. Rigid body motions were treated by moving the mesh rigidly in response to the applied sinusoidal motion. For NACA 0012 airfoil, a validation of the unsteady aerodynamics loads is first considered. Furthermore, a study for understanding the influence of motion parameters, the Mach number, mean angle of incidence, reduced frequency, amplitude, was also conducted. A reverse of the trend of hysteretic loops can be observed with the increasing of the Mach number. Nonlinear hysteretic loops are turned up when increasing the amplitude and the reduced frequency during the applied pitch sinusoidal motion.
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Zeng, Xiao-Hui, Jiang Lai, and Han Wu. "Hunting Stability of High-Speed Railway Vehicles Under Steady Aerodynamic Loads." International Journal of Structural Stability and Dynamics 18, no. 07 (July 2018): 1850093. http://dx.doi.org/10.1142/s0219455418500931.
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With the rising speed of high-speed trains, the aerodynamic loads become more significant and their influences on the hunting stability of railway vehicles deserve to be considered. Such an effect cannot be properly considered by the conventional model of hunting stability analysis. To this end, the linear hunting stability of high-speed railway vehicles running on tangent tracks is studied. A model considering the steady aerodynamic loads due to the joint action of the airflow facing the moving train and the crosswind, is proposed for the hunting stability analysis of a railway vehicle with 17 degrees of freedom (DOF). The key factors considered include: variations of the wheel–rail normal forces, creep coefficients, gravitational stiffness and angular stiffness due to the actions of the aerodynamic load, which affects the characteristics of hunting stability. Using the computer program developed, numerical calculations were carried out for studying the behavior of the linear hunting stability of vehicles under steady aerodynamic loads. The results show that the aerodynamic loads have an obvious effect on the linear critical speeds and instability modes. The linear critical speed decreases monotonously as the crosswind velocity increases, and the influences of pitch moment and lift force on the linear critical speed are larger than the other components of the aerodynamic loads.
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Niven, A. J., and S. W. Tait. "A new approach to the third order calibration of internal strain gauge balances used for aerodynamic load measurement." Aeronautical Journal 104, no. 1041 (November 2000): 501–8. http://dx.doi.org/10.1017/s0001924000017875.
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Abstract With respect to wind tunnel aerodynamic load measurement, an internal strain gauge balance (often referred to as a sting balance) is essentially a compact load cell designed to fit within a cavity of the aerodynamic body and form a link between the model and a fixed ground point via a sting support system. The structure of an internal strain gauge balance is designed to incorporate a series of planar surfaces such that the deflection of each surface is predominantly induced by a unique aerodynamic load. Strain gauges, mounted on groups of surfaces in a Wheatstone bridge arrangement produce output signals proportional to the applied aerodynamic loads. A strain gauge balance is calibrated by applying known loads, measuring the bridge outputs and then formulating an equation which relates the two variables together. Although calibration techniques are well established, reservations have been recently expressed concerning the ability of the associated calibration equation to satisfactorily model the response of the balance when subjected to a six component aerodynamic loading. This generally accepted calibration equation (referred to here as the traditional equation) results in a quadratic approximation to the behaviour of the output signals with applied loads, whereas a more appropriate variation would be cubic. Other limitations of the traditional calibration equation are that the behaviour of the balance to two simultaneously applied loads is based upon limited combinations of the two applied loads, and that the acquisition of the required loads from the strain gauge signals is frequently based upon an approximate matrix inversion method. The proposed calibration equation, described within this paper, models the behaviour of the sting balance to the third order, takes account of all possible combinations of two simultaneously applied loads, and avoids the use of an approximate matrix inversion when deriving the desired aerodynamic loading from the signal outputs. It is also shown that the proposed method may be used to determine the interaction of all possible combinations of up to three simultaneously applied loads.
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Zhang, Hui, Jie Li, and Qiong Liu. "Flight Loads Analysis of a Maneuvering Transport Aircraft." Advanced Materials Research 1016 (August 2014): 460–64. http://dx.doi.org/10.4028/www.scientific.net/amr.1016.460.
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The paper provides a method applicable for the determination of flight loads for maneuvering aircraft, in which aerodynamic loads are calculated based on doublet lattice method, which contains three primary steps. Firstly, non-dimensional stability and control derivative coefficients are obtained through solving unsteady aerodynamics in subsonic flow based on a doublet lattice technical. These stability and control derivative coefficients are used in second step. Secondly, the simulation of aircraft dynamic maneuvers is completed utilizing fourth order Runge-Kutta method to solve motion equations in different maneuvers to gain response parameters of aircraft due to the motion of control surfaces. Finally, the response results calculated in the second step are introduced to the calculation of aerodynamic loads. Thus, total loads and loads distribution on different components of aircraft are obtained. According to the above method, abrupt pitching maneuvers, rolling maneuvers and yawing maneuvers are investigated respectively.
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ABUMERE, AKHANOLU, and EIZIELEN AHIANBA JOSEPH. "THE RELEVANCE OF AERODYNAMICS IN ARCHITECTURE." FAR Journal of Arts, Humanities and Social Studies (FARJAHSS) 2, no. 3 (May 21, 2025): 16–17. https://doi.org/10.5281/zenodo.15480265.
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Aerodynamics plays a crucial role in shaping the architectural design, improving and influencing the performance, sustainability and functionality of buildings and structures. By understanding air-flow patterns, wind loads and pressure distribution around structures, architects and structural engineers can create buildings that are not only aesthetically-pleasing but also functional, efficient and resilient. The relevance of aerodynamics in architecture is multifaceted. It deals with the design of building shapes, orientations and layouts to minimize wind-induced loads, reduce energy consumption and enhance indoor air quality. Aerodynamic principles also guide the placement and design of ventilation, reducing the need for mechanical systems, and improving occupant comfort. In addition, aerodynamics can influence the urban planning and design of cities. By understanding wind patterns and airflow in urbanized areas, architects and urban planners can design cities that are more livable, sustainable and resilient to environmental challenges. By examining case studies of iconic buildings and cutting-edge designs, this research demonstrates how aerodynamic principles can be applied to reduce wind loads, enhance natural ventilation, and create sustainable buildings<em>.</em>
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Yin, F. F., J. J. Chen, X. K. Li, Z. L. Ye, W. Tang, X. Shen, and X. J. Guo. "A blade element momentum model for dual-rotor wind turbines considering inter-rotor velocity interferences." Journal of Physics: Conference Series 2265, no. 4 (May 1, 2022): 042058. http://dx.doi.org/10.1088/1742-6596/2265/4/042058.
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Abstract A blade element momentum model for predicting the aerodynamic performance of dual-rotor wind turbines (DRWTs) as an aerodynamic design tool is introduced in this paper. The model considers the inter-rotor axial velocity reduction and the tangential velocity components in the front rotor’s wake to model the inter-rotor velocity interferences for the inflow velocity as the input of the BEM theory. A DRWT with two NREL 5MW rotors is studied using the present model and CFD simulations. Results from the two methods show good agreements with each other in the trends of power, thrust, and aerodynamic loads on the blades despite the error in near-tip regions. The present DRWT configurations have lower optimum tip speed ratios and a wider range of high-CP speeds. The maximum efficiency of the present turbine is improved by only 5%, indicating that a dedicated blade design for DRWT aerodynamics is required to enhance power output and lower the aerodynamic loads.
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Fontanella, A., A. Facchinetti, and M. Belloli. "Wind tunnel hardware-in-the-loop experiments about the global response of a 15 MW floating wind turbine." Journal of Physics: Conference Series 2626, no. 1 (October 1, 2023): 012059. http://dx.doi.org/10.1088/1742-6596/2626/1/012059.
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Abstract This work describes a new wind tunnel hybrid experiment investigating the aerodynamics and the global response of a 15 MW floating wind turbine. The floater motion is realized with a 6-degrees-of-freedom robotic platform controlled with a hardware-in-the-loop system, in which aerodynamic forces developed by the turbine model are the input of a numerical simulation of the floater dynamics, hydrodynamic excitation, and mooring. It is shown that accuracy of the aerodynamic force feedback from the wind turbine is critical to reproduce the floating wind turbine motion, and measurement of aerodynamic loads is more uncertain in case of pitch motion that movement in the other directions. Free decay tests show that damping of platform surge, pitch, and yaw modes is increased with wind and operating wind turbine compared to the no wind case. The effect of aerodynamic loads on the platform response with stochastic waves is small in the wave frequency range, whereas response of the surge mode is increased with wind.
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Gennaretti, M., and C. Ponzi. "Finite-state aerodynamic modelling for gust load alleviation of wing–tail configurations." Aeronautical Journal 103, no. 1021 (March 1999): 147–58. http://dx.doi.org/10.1017/s0001924000064964.
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Abstract A finite-state aerodynamics methodology is proposed for the analysis of the forces generated by a gust. To illustrate and assess the methodology, gust-response and gust-alleviation applications are included. Finite-state aerodynamics denotes a technique to approximate aerodynamic loads so as to yield an aircraft model of the type ẋ = Ax + Bu (state-space formulation). In this paper, a finite-state formulation is proposed to include the presence of a gust. The aerodynamic loads to be approximated are evaluated here by using a frequency-domain boundary-element formulation; the flow is assumed to be irrotational except for a zero-thickness vortex layer (wake). The gust-alleviation application consists of determining a control law for reducing the response to a vertical gust disturbance, as measured by the centre of mass acceleration. Two optimal-control approaches are considered for the synthesis of the control law: one uses the classical linear-quadratic regulator (LQR), whereas the second includes the additional feed-forward of the gust velocity ahead of the aircraft. Deflections of ailerons and elevators are assumed to be the control variables. Numerical results deal with responses to both a deterministic ‘1 – cosine’ gust distribution and a stochastic von Kármán spectrum. They indicate that the finite-state aerodynamic model proposed is capable of approximating, with a high level of accuracy, both the aerodynamic loads induced by the aircraft kinematics variables and those induced by the control variables, over a wide frequency range.
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Vorobyev, A. A., Y. S. Vatulin, and E. Yu Chistyakov. "Evaluation of stability of high-speed rolling stock on viaducts under increased peak wind load." BRIСS Transport 4, no. 1 (May 14, 2025): 3. https://doi.org/10.46684/2025.1.3.
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The authors have performed the numerical modelling of aerodynamic loads on a high-speed train running on a viaduct and evaluated the stability of a train based on the minimum load pressure on the wheel under the combined effects of crosswind and inertial air pressure (known as drift). The distribution of air pressure on the surface of train body elements in areas of overpressure and rarefaction was mapped out. The study has identifi ed the combinations of aerodynamic impacts under which the loads on bogie wheels may decrease to unacceptable levels and established the maximum speed limits for varying aerodynamic loads that arise on coastal railway lines under stormy weather
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Gennaretti, M., and G. Bernardini. "Aeroelastic response of helicopter rotors using a 3D unsteady aerodynamic solver." Aeronautical Journal 110, no. 1114 (December 2006): 793–801. http://dx.doi.org/10.1017/s0001924000001664.
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The prediction of blade deflections and vibratory hub loads concerning helicopter main rotors in forward flight is the objective of this work. They are determined by using an aeroelastic model derived through the coupling between a nonlinear blade structural model and a boundary integral equation solver for three-dimensional, unsteady, potential aerodynamics. The Galerkin method is used for the spatial integration, whereas the periodic blade response is determined by a harmonic balance approach. This aeroelastic model yields a unified approach for aeroelastic response and blade pressure prediction that may be used for aeroacoustic purposes, with the possibility of including effects from both blade-vortex interaction and multiple-body aerodynamic interaction. Quasi-steady aerodynamic models with wake-inflow from the three-dimensional aerodynamic solver are also applied, in order to perform a comparative study. Numerical results show the capability of the aeroelastic tool to evaluate blade response and vibratory hub loads for a helicopter main rotor in level flight conditions, and examine the sensitivity of the predictions on the aerodynamics model used.
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Martín-San-Román, Raquel, Jon Cerrada-Garcés, Guillén Campaña-Alonso, Beatriz Méndez-López, José Azcona-Armendáriz, and Alvaro Cuerva-Tejero. "Assessment of the azimuthal loads variation by a bi-rotor configuration." Journal of Physics: Conference Series 2767, no. 2 (June 1, 2024): 022015. http://dx.doi.org/10.1088/1742-6596/2767/2/022015.
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Abstract Multi wind turbine configurations are emerging in the offshore wind energy market. The modelling of the aerodynamics of these systems is challenging, due to the small lateral distance between rotors and the subsequent interaction between wakes. Previous analysis in the literature showed that, due to this interaction, multi wind turbine concepts present the advantage of an increment in power production, if the rotors are laterally aligned. However, the counterpart in the variation of the blade loads throughout the revolution, has yet to be analysed in depth. This study focuses on the differences observed in azimuthal cycles of blade aerodynamic loads in side-by-side bi-rotor configurations, as an initial analysis of their potential impact on fatigue loads. The analysis has been developed using two aerodynamic codes, with different levels of fidelity. These models are: a Free Vortex filament Method (FVM) combined with an unsteady Lifting Line (LL) model, and a URANS-blade resolved approach. The simulations show that the sectional blade loads are affected by the adjacent rotor, changing the shape of the aerodynamic load cycles along the azimuth. The load azimuthal distributions predicted by a FVM and a URANS models have been compared, showing agreement on the shape of the cycle with slight differences on maximum peak values, specially at the inner sections of the blade. The FVM model has predicted increments in the blade load cycles, with respect to a single rotor case, with a maximum amplitude of a 3% for out-of-plane forces, and a 8% for in-plane forces. The difference in the azimuthal position of both rotors (phase shift angle) mainly affects the azimuthal shape and not so much the characteristic amplitude of these cycles. Finally, including geometric angles as tilt or pre-cone, produces imbalances between the blade sectional forces of the different rotors.
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Ma, Kaichao, Changhong Tang, Jianye Zhang, Xiaofei Niu, and Qingzhi Fan. "Flight Load Design of Nacelle of Carrier-Based Propeller Transport Aircraft." Xibei Gongye Daxue Xuebao/Journal of Northwestern Polytechnical University 38, no. 6 (December 2020): 1249–56. http://dx.doi.org/10.1051/jnwpu/20203861249.
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The carrier-based propeller transport aircraft has a compact layout, where the large nacelle in size and weight is sensitive to propeller slipstream, and thus calls for sophisticated flight load design studies, which are still insufficient considering domestic experience. In detail, the design methods on aerodynamic load, inertial load, gyrostatic moment, as well as studies on design criteria and maneuver simulation technology are shown for a reference aircraft. The design range applied to this nacelle's flight load is firstly determined by understanding and selecting the design criteria. The typical loadcases of the nacelle are derived from aircraft maneuver simulation. The data of pressure distribution under a series of propeller slipstream strengths is obtained by CFD method. The Design Loads and Design Loadcases of the nacelle are calculated and selected. The effects of the propeller slipstream are compared in an example of the increment on aerodynamic load in a maneuver. The results show that the Design Loads of the nacelle are obtained from the abrupt pitching maneuver under the maximum normal load factor (Nz), the yawing maneuver under the Design Dive Speed(VD), and the maximum propeller pull under the maximum landing weight; the transverse loads of the nacelle are dominated by the aerodynamic load, and the normal loads are dominated by the inertial load, in which the inertial force exceeds the aerodynamic force by 4 times under the extreme circumstances. In some manoeuvres or status, the total aerodynamic force of the whole nacelle is increased by above 90% due to propeller slipstream; the front part of the nacelle which is close to the propeller sees a much bigger increment.
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Abedi, Hamidreza, and Claes Eskilsson. "Wind Turbine Aerodynamics Simulation Using the Spectral/hp Element Framework Nektar++." Wind 5, no. 1 (February 18, 2025): 6. https://doi.org/10.3390/wind5010006.
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Wind power plays an increasingly vital role in sustainable energy development. However, accurately simulating wind turbine aerodynamics, particularly in offshore wind farms, remains challenging due to complex environmental factors such as the marine atmospheric boundary layer. This study investigates the integration and assessment of the Actuator Line Model (ALM) within the high-order spectral/hp element framework, Nektar++, for wind turbine aerodynamic simulations. The primary objective is to evaluate the implementation and effectiveness of the ALM by analyzing aerodynamic loads, wake behavior, and computational demands. A three-bladed NREL-5MW turbine is modeled using the ALM in Nektar++, with results compared against established computational fluid dynamics (CFD) tools, including SOWFA and AMR-Wind. The findings demonstrate that Nektar++ effectively captures velocity and vorticity fields in the turbine wake while providing aerodynamic load predictions that closely align with finite-volume CFD models. Furthermore, the spectral/hp element framework exhibits favorable scalability and computational efficiency, indicating that Nektar++ is a promising tool for high-fidelity wind turbine and wind farm aerodynamic research.
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Elangovan, Karthikvel, and S. Nadaraja Pillai. "Effect of Pitch Angle on Structural and Aerodynamic Characteristics of Vertical-Axis Wind Turbines (VAWTs) Using Leading-Edge Protuberance Blades." Energies 18, no. 2 (January 10, 2025): 286. https://doi.org/10.3390/en18020286.
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An experimental investigation was carried out to understand the effects of LEP (leading-edge protuberance) blades on the structural characteristics of VAWTs. A series of experiments were performed on VAWTs with straight and LEP blades for a wide range of wind velocity (6 m/s to 20 m/s) and pitch angles (−20° to 20°), and the structural excitations on the VAWT structure were measured using a triaxial accelerometer in each case. The raw acceleration data were extensively processed in the time and frequency domains to identify the variation in structural excitation caused by the unsteady wind and aerodynamic loads on the VAWT structure. Understanding the aerodynamic changes and their impact on structural characteristics is essential. The current study examines how LEP influences the structural excitation of VAWTs. However, a great deal of aerodynamic variation was observed for the LEP blades, so the straight blades of the VAWT were replaced with various modified LEP blades, for which a similar set of experiments was carried out. The study presents a better performance (self-starting, stall-mitigating) for VAWTs with LEP 3 and 2 blades, with a significant reduction in the excitation of loads due to wind load and the changes in aerodynamics observed in the along- and across-wind directions.
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Pei, Xi, Min Xu, and Dong Guo. "Aeroelastic-Acoustics Numerical Simulation Research." Applied Mechanics and Materials 226-228 (November 2012): 500–504. http://dx.doi.org/10.4028/www.scientific.net/amm.226-228.500.
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The generation of aerodynamic noise of aircraft in flight is due to dynamical system and aerodynamic .The response of aircraft subjected to High acoustic loads and aerodynamic loads can produce fatigue and damage. In this paper a new Aeroelastic- Acoustics which adds acoustic loads in aeroelastic is presented. The emphasis of the study is the discipline of displacement and load of the flexible structure under the unsteady aerodynamic, inertial, elastic and aero-acoustic. The CFD/CSD/CAA coupling is used to simulate rockets cabin. Sound generated by a rocker is predicted numerically from a Large Eddy simulation (LES) of unsteady flow field. The Lighthill acoustic analogy is used to model the propagation of sound. The structural response of rocket cabin was given. The boundary-layer transition on the pressure side of the cabin is visualized, by plotting to better illustrate the essential interaction between fluctuating pressure and structure.CFD/CSD/CAA coupling compute method is validated in low and middle frequency.
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Amrutheswara Krishnamurthy and Dr.Suresh Nagesh. "Aerodynamic Effect on Stability and Lift Characteristics of an Elevated Sedan Car." ARAI Journal of Mobility Technology 2, no. 2 (May 13, 2022): 205–13. http://dx.doi.org/10.37285/ajmt.1.2.6.
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There is a strong interaction between air and vehicle components. Aerodynamics plays a significant role in a vehicle's fuel efficiency. The contact patch load between the tire and road is directly related to the vehicle load. In this research, the lift forces generated due to the additional wing attached to the car model with different spans and heights of the wing location from the car body is considered for study. The loads due to change in Angle of Attack (AOA) and their effect on the tire loads are studied. The upward vertical force produced from aerodynamic loads reduces the wheel load of the car virtually. A tire's coefficient of friction would decrease with upward vertical force. This balance load implies that a lightweight car would make more efficient use of its tires than a heavier car. ANSYS Fluent is used for the Computational Fluid Dynamics (CFD) study. The validation of airflow characteristics, lift and drag forces from simulations are done with wind tunnel testing data. Varying the angle of attack, wingspan, height between the car and the wing's lower surface, one can increase the capacity of the payload by 10% or fuel efficiency by 10% to 20%.
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Petrone, Nicola, Matteo Capuzzo, Erik De Paoli, and Nicola Biliato. "The Measurement of Aerodynamic Loads using Dynamometric Load Cells." ATZautotechnology 4, no. 3 (May 2004): 56–59. http://dx.doi.org/10.1007/bf03246829.
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Cicolani, L. S., J. G. A. da Silva, E. P. N. Duque, and M. B. Tischler. "Unsteady aerodynamic model of a cargo container for slung-load simulation." Aeronautical Journal 108, no. 1085 (July 2004): 357–68. http://dx.doi.org/10.1017/s0001924000005170.
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Abstract The problem of simulation models capable of predicting the aerodynamic instability of helicopter slung-load cargo containers and bluff bodies is addressed. Instability for these loads is known to depend on unsteady frequency-dependent aerodynamics, but simulation models that include the unsteady aerodynamics do not currently exist. This paper presents a method for generating such models using computational fluid dynamics (CFD) to generate forced-oscillation aerodynamic data and frequency domain system identification techniques to generate a frequency response from the CFD data and to identify a transfer function fit to the frequency response. The method is independent of the responsible flow phenomenon and is expected to apply to bluff-bodies generally. Preliminary results are presented for the case of the 6- by 6- by 8-ft CONEX (container express) cargo container. The present work is based on two-dimensional (2D) aerodynamic data for the CONEX side force and yaw moment generated by a forced oscillation in which frequency is varied smoothly over the range of interest. A first-order rational polynomial transfer function is found adequate to fit the aerodynamics, and this is shown to provide a good match with flight test data for the yawing motion of the CONEX.
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Schulz, Christian W., Umut Özinan, Stefan Netzband, Po Wen Cheng, and Moustafa Abdel-Maksoud. "The Impact of Unsteadiness on the Aerodynamic Loads of a Floating Offshore Wind Turbine." Journal of Physics: Conference Series 2626, no. 1 (October 1, 2023): 012064. http://dx.doi.org/10.1088/1742-6596/2626/1/012064.
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Abstract The role of unsteadiness in the aerodynamics of Floating Offshore Wind Turbines (FOWT) remains a subject of discussion among the research community. Therefore, it must be investigated whether and to what extent transient aerodynamic phenomena impact the loads of a wind turbine rotor undergoing motions in unsteady winds. The study of transient aerodynamic phenomena is closely linked to the question of whether the modern Blade Element Momentum Theory (BEMT) methods can be considered reliable for the simulation of FOWTs. In this work, investigations are carried out to identify the relevant transient aerodynamic phenomena and quantify their effects on the torque and thrust of the Floatgen wind turbine. A free-wake panel method is utilised to identify and quantify transient parts of the load response to a set of simplified unsteady scenarios: a wind gust, a harmonic surge motion and a rotor speed oscillation. Transient contributions to the load behaviour of the wind turbine can be identified in all scenarios under consideration. In addition, the ability of a state-of-the-art BEMT method to model the identified transient contributions is evaluated. While an agreement of the qualitative impact of the transient aerodynamic phenomena at moderate motion frequencies is found, a contradicting behaviour of the simulation models becomes apparent at high motion frequencies. This indicates the presence of a transient, three-dimensional wake effect that cannot be reproduced by the common unsteady corrections for BEMT methods.
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Huang, Taiming, Zhengqi Gu, Chengjie Feng, and Wei Zeng. "Transient aerodynamics simulations of a road vehicle in the crosswind condition coupled with the vehicle’s motion." Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering 232, no. 5 (August 11, 2017): 583–98. http://dx.doi.org/10.1177/0954407017704609.
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The influence of transient aerodynamics on a vehicle in a crosswind and the effect on the vehicle’s motion are investigated by employing fully coupled simulations. The fully coupled method makes the simulation data on the fluid dynamics and on the vehicle dynamics exchange in time. LES are used to investigate the movement of the transient turbulence, and wind tunnel experiments are carried out to validate the numerical method. The vehicle is simplified as a three-degree-of-freedom system which moves in only the horizontal direction. The driver’s reaction is considered when the motion of the vehicle is simulated. The results of fully coupled simulations show that the transient aerodynamic loads have a marked influence on the motion of the vehicle. The transitional method of one-way coupled simulations is also employed to obtain data. The simulation results for the two methods are compared with each other. It is found that there is large difference between the results of the two methods. The maximum side force in fully coupled simulations is about 1.22 times the value obtained by the transitional method, and there is a 0.2 m discrepancy between the peak value of the lateral displacement in fully coupled simulations and the peak value in the transitional method. The results show that the transient aerodynamic loads induced by the unsteady motion of the vehicle have a larger effect on the vehicle’s motion than do the aerodynamic loads from the transitional method. Furthermore, the results also reflect the significance of estimating the transient aerodynamic loads in simulations of the vehicle’s motion.
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Xie, Yonghui, Kun Lu, Le Liu, and Gongnan Xie. "Fluid-Thermal-Structural Coupled Analysis of a Radial Inflow Micro Gas Turbine Using Computational Fluid Dynamics and Computational Solid Mechanics." Mathematical Problems in Engineering 2014 (2014): 1–10. http://dx.doi.org/10.1155/2014/640560.
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A three-dimensional fluid-thermal-structural coupled analysis for a radial inflow micro gas turbine is conducted. First, a fluid-thermal coupled analysis of the flow and temperature fields of the nozzle passage and the blade passage is performed by using computational fluid dynamics (CFD). The flow and heat transfer characteristics of different sections are analyzed in detail. The thermal load and the aerodynamic load are then obtained from the temperature field and the pressure distribution. The stress distributions of the blade are finally studied by using computational solid mechanics (CSM) considering three cases of loads: thermal load, aerodynamics load combined with centrifugal load, and all the three types of loads. The detailed parameters of the flow, temperature, and the stress are obtained and analyzed. The numerical results obtained provide a useful knowledge base for further exploration of radial gas turbine design.
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Zyl, L. H. van. "2D and 3D low frequency aerodynamics." Aeronautical Journal 112, no. 1136 (October 2008): 609–12. http://dx.doi.org/10.1017/s0001924000002578.
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Abstract Unsteady aerodynamic loads on aircraft configurations are used for aeroelastic or flight dynamic analyses. The sources for deriving these loads include strip theory aerodynamics and three-dimensional panel methods. In some applications the behaviour of the unsteady air loads as the frequency approaches zero is important, and it is well known that the behaviour of strip theory aerodynamics employing the exact circulation function differs qualitatively from that of the three-dimensional panel methods such as the subsonic doublet lattice method (DLM). Theoretical results from an earlier study of the low frequency behaviour of the DLM are used here to show the relationship between the DLM and strip theory and the relationship is verified by a numerical example.
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Sakib, Mohammad Sadman, and D. Todd Griffith. "Parked and operating load analysis in the aerodynamic design of multi-megawatt-scale floating vertical-axis wind turbines." Wind Energy Science 7, no. 2 (March 24, 2022): 677–96. http://dx.doi.org/10.5194/wes-7-677-2022.
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Abstract. A good understanding of aerodynamic loading is essential in the design of vertical-axis wind turbines (VAWTs) to properly capture design loads and to estimate the power production. This paper presents a comprehensive aerodynamic design study for a 5 MW Darrieus offshore VAWT in the context of multi-megawatt floating VAWTs. This study systematically analyzes the effect of different, important design variables including the number of blades, aspect ratio and blade tapering in a comprehensive load analysis of both the parked and operating aerodynamic loads including turbine power performance analysis. The number of blades is studied for two- and three-bladed turbines, aspect ratio is defined as ratio of rotor height and rotor diameter and studied for values from 0.5 to 1.5, and blade tapering is applied by means of adding solidity to the blades towards blade root ends, which affects aerodynamic and structural performance. Analyses were carried out using a three-dimensional vortex model named CACTUS (Code for Axial and Cross-flow TUrbine Simulation) to evaluate both instantaneous azimuthal parameters as well as integral parameters, such as loads (thrust force, lateral force and torque loading) and power. Parked loading is a major concern for VAWTs; thus, this work presents a broad evaluation of parked loads for the design variables noted above. This study also illustrates that during the operation of a turbine, lateral loads are on par with thrust loads, which will significantly affect the structural sizing of rotor and platform and mooring components.
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Lu, Yaohui, Dewen Zhang, Heyan Zheng, Chuan Lu, Tianli Chen, Jing Zeng, and Pingbo Wu. "Analysis of the aerodynamic pressure effect on the fatigue strength of the carbody of high-speed trains passing by each other in a tunnel." Proceedings of the Institution of Mechanical Engineers, Part F: Journal of Rail and Rapid Transit 233, no. 8 (November 2, 2018): 783–801. http://dx.doi.org/10.1177/0954409718809469.
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When two high-speed trains pass through a tunnel, the aerodynamic changes are more complex and drastic than in open air owing to the interference of the tunnel wall and the entry effect. The impact on the carbody fatigue strength is very significant in the fatigue reliability design of the carbody. In this paper, the sequential coupling method was used for the first time to study the effect of pressure waves on the fatigue strength in a large-scale and complex carbody structure. The computational fluid dynamics method was used to calculate and analyze the aerodynamic pressure wave of the intersection of the trains in a long and short tunnel. A full-scale finite element shell model of the carbody structure was established. Then, the time integration method was used to convert the transient pressure wave into the aerodynamic loads bearing by the side wall of the carbody. The inhomogeneous stress concentrations at the restraint points were eliminated by the inertial release method; moreover, a finite element analysis of the carbody was carried out under the combined aerodynamic and mechanical loads. The Goodman fatigue strength curve of the aluminum alloy carbody was drawn. The influence of the aerodynamic load on the fatigue strength of the vehicle body was analyzed and compared under the entry effect of the short tunnel. The results show that the aerodynamic load of the short tunnel has a significant impact on the fatigue strength of the carbody owing to the train's entry effect. The safety factor of the fatigue strength is 15% less than that of the long tunnel aerodynamic load. In this paper, computational fluid dynamics and finite element method were used to analyze and evaluate the impact of the pressure wave on the fatigue strength of the carbody, which is of great reference value in the structural design of the carbody subjected to complex aerodynamic loads.
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Shen, Xin, Ping Hu, Jinge Chen, Xiaocheng Zhu, and Zhaohui Du. "The unsteady aerodynamics of floating wind turbine under platform pitch motion." Proceedings of the Institution of Mechanical Engineers, Part A: Journal of Power and Energy 232, no. 8 (March 29, 2018): 1019–36. http://dx.doi.org/10.1177/0957650918766606.
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The aerodynamic performance of floating platform wind turbines is much more complex than fixed-base wind turbines because of the flexibility of the floating platform. Due to the extra six degrees-of-freedom of the floating platform, the inflow of the wind turbine rotors is highly influenced by the motions of the floating platform. It is therefore of interest to study the unsteady aerodynamics of the wind turbine rotors involved with the interaction of the floating platform induced motions. In the present work, a lifting surface method with a free wake model is developed for analysis of the unsteady aerodynamics of wind turbines. The aerodynamic performance of the NREL 5 MW floating wind turbine under the prescribed floating platform pitch motion is studied. The unsteady aerodynamic loads, the transient of wind turbine states, and the instability of the wind turbine wakes are discussed in detail.
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Silva, Adriana Correia da, and Michael Muskulus. "VAWT support structure mass sensitivity due to aerodynamic load scaling." Journal of Physics: Conference Series 2626, no. 1 (October 1, 2023): 012003. http://dx.doi.org/10.1088/1742-6596/2626/1/012003.
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Abstract The X-rotor wind turbine is an X-shaped hybrid vertical axis wind turbine whose power take-off is done by horizontal axis rotors located at the tip of the lower blades. Based on an initial basic study, the present study developed a preliminary jacket design as the turbine support structure. Steady aerodynamic loads were obtained from an actuator cylinder model and dynamic load simulations including wave loads were performed. The structure was checked according to fatigue damage and maximum yielding for representative site-specific load cases for fatigue and ultimate limit states. Even though the use of a conventional jacket was shown to be feasible for the new turbine concept, the overall mass of the support structure obtained by the higher fidelity model was higher than the initial prediction. The design was driven by the fatigue damage, caused by large cyclical loads on every rotor rotation. The effect of a hypothetical aerodynamic load reduction on the jacket mass was investigated. The developed design methodology was also applied to the design of equivalent jackets after a load reduction of 75% and 50% and the mass of the structure was shown to be sensible, with a respective reduction of 25% and 48%. This result demonstrates that different design strategies that influence the magnitude of the aerodynamic loads (e.g. the control strategy) could lead to a more cost-efficient jacket design.
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Da, Silva Adriana Correia, and Michael Muskulus. "VAWT support structure mass sensitivity due to aerodynamic load scaling." Journal of Physics: Conference Series 2626 (June 5, 2023): 10 / 012003. https://doi.org/10.1088/1742-6596/2626/1/012003.
Pełny tekst źródłaStreszczenie:
The X-rotor wind turbine is an X-shaped hybrid vertical axis wind turbine whose power take-off is done by horizontal axis rotors located at the tip of the lower blades. Based on an initial basic study, the present study developed a preliminary jacket design as the turbine support structure. Steady aerodynamic loads were obtained from an actuator cylinder model and dynamic load simulations including wave loads were performed. The structure was checked according to fatigue damage and maximum yielding for representative site-specific load cases for fatigue and ultimate limit states. Even though the use of a conventional jacket was shown to be feasible for the new turbine concept, the overall mass of the support structure obtained by the higher fidelity model was higher than the initial prediction. The design was driven by the fatigue damage, caused by large cyclical loads on every rotor rotation. The effect of a hypothetical aerodynamic load reduction on the jacket mass was investigated. The developed design methodology was also applied to the design of equivalent jackets after a load reduction of 75% and 50% and the mass of the structure was shown to be sensible, with a respective reduction of 25% and 48%. This result demonstrates that different design strategies that influence the magnitude of the aerodynamic loads (e.g. the control strategy) could lead to a more cost-efficientjacket design.
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Kowaleczko, Grzegorz, and Andrzej Leśniczak. "Modelling of Helicopter Main Rotor Aerodynamic Loads in Manoeuvres." Journal of KONES 26, no. 4 (December 1, 2019): 273–84. http://dx.doi.org/10.2478/kones-2019-0118.
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AbstractThe article discusses the method of modelling of the helicopter main rotor aerodynamic loads during steady state flight and manoeuvres. The ability to determine these loads was created by taking into account the motion of each blade relative to the hinges and was a result of the applied method of aerodynamic loads calculating. The first part of the work discusses the basic relationships that were used to build the mathematical model of helicopter flight. The focus was also on the method of calculating of the aerodynamic forces generated by the rotor blades. The results of simulations dedicated to the “jump to hover” manoeuvre were discussed, showing the possibilities of analysing aerodynamic loads occurring in unsteady flights. The main rotor is considered separately in an “autonomous” way and treated as a source of averaged forces and moments transferred to the hub. The motion of individual blades is neglected, and their aerodynamic characteristics are radically simplified. The motion of individual blades is neglected, and their aerodynamic characteristics are radically simplified. This can lead to significant errors when attempting to model dynamic helicopter manoeuvres. The more complex model of helicopter dynamics is discussed.
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Ben Hassen, Mariem, Slim Ben-Elechi, and Hatem Mrad. "Crack Propagation in Axial-Flow Fan Blades Under Complex Loading Conditions: A FRANC3D and ABAQUS Co-Simulation Approach." Applied Sciences 15, no. 3 (February 5, 2025): 1597. https://doi.org/10.3390/app15031597.
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Since fan blades are exposed to fatigue, and in some cases harsh loading conditions, they may exhibit fracture failures due to crack propagation, resulting in significant losses. Previous studies of crack propagation in blades are mainly confined to either simplified blade geometry or loads, resulting in a significant discrepancy between the simulated crack propagation and the real blade propagation behavior, while it is lacking for challenging shapes and loads. A co-simulation approach of FRANC3D and ABAQUS was developed to study the crack propagation of an axial-flow fan blade subjected to centrifugal, aerodynamic, and combined loads. The projected approach is validated with results obtained from analytical calculations and experiments. Meanwhile, making use of benchmarks, the Stress Intensity Factor (SIF) and the prediction of mixed-mode crack growth path are validated. Considering various loads, the crack propagation path response for the fan blade is computed for different growth steps. The results pinpoint that the crack propagation length of the crack tip center is maximum under centrifugal loading. However, the aerodynamic load led to a maximum propagation length of the crack tip endpoints. In addition, the combined force of centrifugal and aerodynamic loads limits the crack from growing.
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Morales, Eduardo, Mario Chávez, Griselda Abarca, Yunuén López, Jesús Mares, and Juan Cruz. "Structural Study on the Impact of Aerodynamic Loads on Winglet Support Structures." International Journal of Engineering, Science and Information Technology 5, no. 3 (May 24, 2025): 112–21. https://doi.org/10.52088/ijesty.v5i3.888.
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Aerodynamic spoilers are intended to reduce drag forces and generate lift on surfaces. However, dynamic operating conditions can affect their performance and that of their supporting structures. This study evaluates the impact of aerodynamic loads on a spoiler's supporting structure using fluid-structure interaction (FSI) analysis. Three NACA airfoil models were analyzed to benchmark their structural behavior. Simulations using Ansys® software modeled the spoiler's airflow-induced pressures and structural displacements, considering dynamic loads derived from a similarity study between a full-scale (1:1) vehicle model and a scaled-down (1:6) version. The results revealed the mechanical behavior of the support under different flow conditions, assimilating the forces produced and how this is affected by the aerodynamics produced on the spoiler, generating data that informs the evaluation of this system and ensures reliability. The optimization of the support model allows for greater control over measurements, which is of great importance for wind tunnel testing, ensuring that evaluations are not affected by mechanical displacements of the support. The CAD model, combined with finite element Methods (FEM), allows visualization of the mechanical and aerodynamic behavior before manufacturing, thereby reducing the time and costs associated with physical testing and allowing critical failure points to be identified. The work includes studies through simulations of the aerodynamic and structural systems of the spoiler supports, generating data that helps understand and facilitate the evaluation of these systems and guarantees their reliability. Computational simulation is an essential tool for development and validation in the automotive sector.
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H, Hanan, and Raiza Susan George. "Advancement of Aerodynamics in Flutter Characteristics of AGARD 445.6 Wing." International Journal for Research in Applied Science and Engineering Technology 11, no. 5 (May 31, 2023): 488–91. http://dx.doi.org/10.22214/ijraset.2023.51513.
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Abstract: The aerospace sector has seen a significant prominence in the field of aerodynamics. Aerodynamic behaviour differs from one structure to the next depending on the specifics of each one. Due to flexible aeroplane structures, aeroelastic phenomena occur, when structural deformations alter aerodynamic forces. A feedback mechanism between the increased structural deformations and the added aerodynamic forces increases further aerodynamic loads. These interactions may diminish until they achieve an equilibrium state or, if resonance takes place, they may diverge drastically. The most challenging to forecast instability aeroelasticity aeroelastic phenomenon is flutter. An accurate finite element aerodynamic wing model is required for flutter study. A review of various approaches for conducting flutter analysis of AGARD 445.6 wing is presented in this paper. AGARD 445.6 wing has been used as standard configuration for the analogy of all aeroelastic behaviours. Under different flow regimes, the paper examines the platforms for finite element software that are used for flutter analysis.
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Kim and Kwon. "Effect of Platform Motion on Aerodynamic Performance and Aeroelastic Behavior of Floating Offshore Wind Turbine Blades." Energies 12, no. 13 (June 30, 2019): 2519. http://dx.doi.org/10.3390/en12132519.
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In the present study, a numerical framework for predicting the aerodynamic performance and the aeroelastic behavior of floating offshore wind turbine rotor blades involving platform motion was developed. For this purpose, the aerodynamic and structural analyses were conducted simultaneously in a tightly coupled manner by exchanging the information about the aerodynamic loads and the elastic blade deformations at every time step. The elastic behavior of the turbine rotor blades was described by adopting a structural model based on the Euler-Bernoulli beam. The aerodynamic loads by the rotor blades were evaluated by adopting a blade element momentum theory. The numerical simulations were conducted when the platform of the wind turbine independently moves in each of the six degrees-of-freedom directions consisting of heave, sway, surge, roll, pitch, and yaw. It was observed that flexible blades exhibit complicated vibratory behaviors when they are excited by the aerodynamic, inertia, and gravitational forces simultaneously. It was found that the load variation caused by the platform surge or pitch motion has a significant influence on the flapwise and torsional deformations of the rotor blades. The torsional deformation mainly occurs in the nose-down direction, and results in a reduction of the aerodynamic loads. It was also found that the flapwise root bending moment is mainly influenced by the platform surge and pitch motions. On the other hand, the edgewise bending moment is mostly dictated by the gravitational force, but is not affected much by the platform motion.
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Han, Y., S. Q. Shu, and D. Tan. "Numerical Simulation on Aerodynamic Characteristics of Road Vehicles on Bridges under Cross Winds." Advanced Materials Research 774-776 (September 2013): 241–47. http://dx.doi.org/10.4028/www.scientific.net/amr.774-776.241.
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The aerodynamic force coefficients of road vehicles under wind loads depend on not only the shapes of vehicles but also those of infrastructures, such as a bridge. Therefore, study of the aerodynamic characteristics of road vehicles considering the interaction of aerodynamic forces between the road vehicles and bridge is necessary for predicting the performance of vehicle under wind loads properly. This paper studies aerodynamic characteristics of road vehicles when vehicles run on bridges under cross winds using the CFD method. The dependence of aerodynamic forces on vehicle speeds, the interaction of aerodynamic forces between the vehicles and bridges and the influence of the turbulence are investigated by different simulation cases.
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Paulauskas, Vytautas, Donatas Paulauskas, and Joep Wijffels. "SHIP SAFETY IN OPEN PORTS." TRANSPORT 24, no. 2 (June 30, 2009): 113–20. http://dx.doi.org/10.3846/1648-4142.2009.24.113-120.
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Ports and terminals open to prevailing winds can cause problems to moored ships with a high freeboard. Such ships, i.e. ship and berth mooring systems, have to deal with significant aerodynamic loads.This paper addresses the theoretical approach of the influence of aerodynamic loads on a mooring system for ship and investigates whether windscreens can reduce aerodynamic loads on ships in ports.