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Prediction Of The Lift And Drag Coefficients Of A Moving Airfoil Using Computational Fluid Dynamics Simulation
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Book Synopsis Prediction of the Lift and Drag Coefficients of a Moving Airfoil Using Computational Fluid Dynamics Simulation by : Fang Gao
Download or read book Prediction of the Lift and Drag Coefficients of a Moving Airfoil Using Computational Fluid Dynamics Simulation written by Fang Gao and published by . This book was released on 2014 with total page 128 pages. Available in PDF, EPUB and Kindle. Book excerpt: ABSTRACT: The purpose of this research is to numerically simulate, analyze, and visualize turbulent flow around rotating aerodynamic shaped 3-dimentional geometries using a custom-made software suite. The computational fluid dynamic program used for this research is called Numerical Wind Tunnel, NWT, which was developed by Dr. J. Militzer and his students over the last 15 years. In order to meet various simulation and prediction requirements of this research, the NWT was modified and improved by implementing many new features; in addition, many bugs have been fixed. Key features added to the NWT include improved boundary layer handling for Detached Eddy Simulation method, new implementations of Surrounding Cell Method and rewritten Lift and Drag Coefficients calculation algorithms, and new approaches to Mesh Refinement and Adaptation Criteria. The improved software is tested extensively by simulating turbulent flows around a rotating National Advisory Committee for Aeronautics (NACA) 0009 airfoil, and test results are compared with both experimental data and previous simulation data. The research was successful mainly because of the much-improved accuracy in predicting static lift and drag coefficients. Another achievement of this research is that the software also successfully predicted various events during an airfoil dynamic stall condition, which is a result of both accurate flow prediction and a NWT feature called Automatic Anisotropic Grid Adaptation.
Book Synopsis Computational Aerodynamic Modeling of Aerospace Vehicles by : Mehdi Ghoreyshi
Download or read book Computational Aerodynamic Modeling of Aerospace Vehicles written by Mehdi Ghoreyshi and published by MDPI. This book was released on 2019-03-08 with total page 294 pages. Available in PDF, EPUB and Kindle. Book excerpt: Currently, the use of computational fluid dynamics (CFD) solutions is considered as the state-of-the-art in the modeling of unsteady nonlinear flow physics and offers an early and improved understanding of air vehicle aerodynamics and stability and control characteristics. This Special Issue covers recent computational efforts on simulation of aerospace vehicles including fighter aircraft, rotorcraft, propeller driven vehicles, unmanned vehicle, projectiles, and air drop configurations. The complex flow physics of these configurations pose significant challenges in CFD modeling. Some of these challenges include prediction of vortical flows and shock waves, rapid maneuvering aircraft with fast moving control surfaces, and interactions between propellers and wing, fluid and structure, boundary layer and shock waves. Additional topic of interest in this Special Issue is the use of CFD tools in aircraft design and flight mechanics. The problem with these applications is the computational cost involved, particularly if this is viewed as a brute-force calculation of vehicle’s aerodynamics through its flight envelope. To make progress in routinely using of CFD in aircraft design, methods based on sampling, model updating and system identification should be considered.
Book Synopsis Computational Fluid Dynamics Drag Prediction: Results from the Viscous Transonic Airfoil Workshop by :
Download or read book Computational Fluid Dynamics Drag Prediction: Results from the Viscous Transonic Airfoil Workshop written by and published by . This book was released on 1988 with total page 22 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Fluent Simulation of Airflow Around Airfoils by : Chunlin Liu
Download or read book Fluent Simulation of Airflow Around Airfoils written by Chunlin Liu and published by . This book was released on 2008 with total page 82 pages. Available in PDF, EPUB and Kindle. Book excerpt: Numerical simulation of flow past airfoils is important in the aerodynamics design of aircraft. The complex commercial computational fluid dynamics software FLUENT provide a convenient way to model fluid flow dynamics problem. To test accuracy of CFD in predicting Lift and Drag coefficient under a wide range of flow conditions. In this thesis, numerical simulation of steady flow around NACA 0012 was conducted using control volume approach in Gambit and Fluent at three different Reynolds Number(Re), 1.0x10[superscript]6, 3.0x10[superscript]6 and 5x10[superscript]6. Lift and drag coefficient were measured for an attack angle between 0[degree] and 16[degree] in 2[degree] intervals. The purpose of this study was to establish a verified solution method in the subsonic and transonic flow regimes around airfoil. The results from FLUENT model were found closely to the published experimental data except for the stall point of the airfoil. The flow field is determined by solving two-dimensional incompressible Navier-Stokers equations while the effects of turbulence are accounted for by the Spalart-Allmaras model. Boundary layer developed at the surfaces of the airfoil is investigated together with relevant pressure and velocity contours for different Attack angle and Reynolds Number. This study shows that CFD can provide accurate predictions under the flow conditional scheduling.
Book Synopsis A Study of Drag Force on Different Type of Airfoil in a Subsonic Wind Tunnel by : Muhamad Faruqi Zahari
Download or read book A Study of Drag Force on Different Type of Airfoil in a Subsonic Wind Tunnel written by Muhamad Faruqi Zahari and published by . This book was released on 2013 with total page 48 pages. Available in PDF, EPUB and Kindle. Book excerpt: There had been a number of researches that investigated on drag force of airfoil in subsonic wind tunnel. This study was then conducted in order to identify drag force in subsonic wind tunnel using Computational Fluid Dynamics (CFD) software. Specifically, this research aimed to identify the drag force on ten different types NACA airfoil. NACA 0006, NACA 0009, NACA 0015, NACA 1408, NACA 1410, NACA 2408, NACA 2418, NACA 4424, NACA 6409 and NACA 6412 airfoil geometry profiles and its coordinates were generated from a NACA 4 Digits Series Generator and then designed by using ANSYS (Fluent) geometry and computed using ANSYS 14.0 software , these Computational Fluid Dynamic was used to simulate the external flow analysis on the airfoils and then the prediction of the drag force validate its simulation result with experimental result of drag force in subsonic wind tunnel. Nonetheless, the boundary condition was operated at a nominal velocity 17 m/s during the coefficient measurements, a Reynolds's number of about 1,163,798. The airfoil, with a one meter chord, was analyzed at zero degree angles of attack. Moreover, the result show NACA 4424 that have highest drag force and NACA 0006 have the lowest drag force at same boundary condition. Furthermore, the drag was generated was too small to make any significant change to the airfoil performance.
Book Synopsis Fluid Mechanics and Fluid Power, Volume 3 by : Krishna Mohan Singh
Download or read book Fluid Mechanics and Fluid Power, Volume 3 written by Krishna Mohan Singh and published by Springer Nature. This book was released on 2024-01-16 with total page 726 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book comprises select peer-reviewed proceedings of the 9th International and 49th National Conference on Fluid Mechanics and Fluid Power (FMFP 2022). This book brings together scientific ideas and engineering solutions put forth by researchers and practitioners from academia and industry in the important and ubiquitous field of fluid mechanics. The contents of this book focus on fundamental issues and perspective in fluid mechanics, measurement techniques in fluid mechanics, computational fluid and gas dynamics, instability, transition and turbulence, fluid-structure interaction, multiphase flows, microfluidics, bio-inspired fluid mechanics, aerodynamics, turbomachinery, propulsion and power and other miscellaneous topics in the broad domain of fluid mechanics. This book is a useful reference to researchers and professionals working in the broad field of mechanics.
Book Synopsis A Conceptual Study of Airfoil Performance Enhancements Using CFD by : Armin Ghoddoussi
Download or read book A Conceptual Study of Airfoil Performance Enhancements Using CFD written by Armin Ghoddoussi and published by . This book was released on 2011 with total page 72 pages. Available in PDF, EPUB and Kindle. Book excerpt: A conceptual study of performance enhancing devices for an airfoil is performed using Computational Fluid Dynamics. Three simple, passive devices are examined to explore alternate methods for stall control and lift-to-drag improvement. The motivation behind this research is to study effective techniques to improve performance with fewer drawbacks than previously existing methods. An evaluation scheme is presented to compute airfoil lift, drag and pitching moment for a range of angles-of-attack up to stall. NACA 641-212 single-element and slatted airfoil CFD results are compared with experimental data to validate the computational model. Evaluations on the first conceptual design (Stall vane) show elimination of the separation at 15 degrees of angle-of-attack where the flow reversal normally starts at 86% - chord. A total drag increase of 22% is detected because of the sharp leading-edge of the device, but the main element drag has a reduction of 43%. The maximum lift coefficient does not show a significant change on the same model. The second device (Cylinder) has a negative effect, initiating flow separation and causing a significant decrease in lift-to-drag ratio at a given lift coefficient. The third device (Dimples) demonstrates the potential of lift-to-drag ratio improvement at the higher angle-of-attack. Further investigation is required to verify the results since the improvement is small.
Book Synopsis Prediction of Airfoil Characteristics With Higher Order Turbulence Models by : Thomas B. Gatski
Download or read book Prediction of Airfoil Characteristics With Higher Order Turbulence Models written by Thomas B. Gatski and published by . This book was released on 1996 with total page 26 pages. Available in PDF, EPUB and Kindle. Book excerpt: This study focuses on the prediction of airfoil characteristics, including lift and drag over a range of Reynolds numbers. Two different turbulence models, which represent two different types of models, are tested. The first is a standard isotropic eddy-viscosity two-equation model, and the second is an explicit algebraic stress model (EASM). The turbulent flow field over a general-aviation airfoil (GA(W)-2) at three Reynolds numbers is studied. At each Reynolds number, predicted lift and drag values at different angles of attack are compared with experimental results, and predicted variations of stall locations with Reynolds number are compared with experimental data. Finally, the size of the separation zone predicted by each model is analyzed, and correlated with the behavior of the lift coefficient near stall. In summary, the EASM model is able to predict the lift and drag coefficients over a wider range of angles of attack than the two-equation model for the three Reynolds numbers studied. However, both models are unable to predict the correct lift and drag behavior near the stall angle, and for the lowest Reynolds number case, the two-equation model did not predict separation on the airfoil near stall.
Book Synopsis CFD-based Aircraft Drag Prediction and Reduction by : H. Deconinck
Download or read book CFD-based Aircraft Drag Prediction and Reduction written by H. Deconinck and published by . This book was released on 2003 with total page 742 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Scientific and Technical Aerospace Reports by :
Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1995 with total page 702 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Investigation Into the Discrepancies Between Computational Fluid Dynamics Lift Predictions and Experimental Results by : Randall Scott Fairman
Download or read book Investigation Into the Discrepancies Between Computational Fluid Dynamics Lift Predictions and Experimental Results written by Randall Scott Fairman and published by . This book was released on 2002 with total page 236 pages. Available in PDF, EPUB and Kindle. Book excerpt: An analysis of current computational fluid dynamics capabilities in predicting mean lift forces for two dimensional foils is conducted. It is shown that both integral boundary layer theory and Reynolds Averaged Navier Stokes algorithms provide the same over-prediction of lift forces when properly converged. It is also shown that the over-prediction is insensitive to turbulence model details. Experimentation and computational fluid dynamics modeling show that discrete vortices are shed with significant sizes and distinct frequencies. These vortices are shown to result in significant cfd prediction errors when they are asymmetric in size or shape. Inaccuracies in flow predictions in the near wake appear to result in an effective change in the Kutta Condition due to pressure biasing associated with vortex asymmetry. The net result is a consistent overprediction of mean lift. Based on an analysis of over 1000 historical experiments an empirical model is developed to allow the error in predicted lift coefficient to be anticipated based on the local flow conditions at the trailing edge of the foil. A series of experiments are conducted and reported to test the accuracy of the empirical model. The result is a significant improvement in mean lift prediction and pressure profile for both RANS and IBLT.
Book Synopsis Recent Development of Aerodynamic Design Methodologies by : Kozo Fujii
Download or read book Recent Development of Aerodynamic Design Methodologies written by Kozo Fujii and published by Springer Science & Business Media. This book was released on 2013-04-17 with total page 228 pages. Available in PDF, EPUB and Kindle. Book excerpt: Computational Fluid Dynamics (CFD) has made remarkable progress in the last two decades and is becoming an important, if not inevitable, analytical tool for both fundamental and practical fluid dynamics research. The analysis of flow fields is important in the sense that it improves the researcher's understanding of the flow features. CFD analysis also indirectly helps the design of new aircraft and/or spacecraft. However, design methodologies are the real need for the development of aircraft or spacecraft. They directly contribute to the design process and can significantly shorten the design cycle. Although quite a few publications have been written on this subject, most of the methods proposed were not used in practice in the past due to an immature research level and restrictions due to the inadequate computing capabilities. With the progress of high-speed computers, the time has come for such methods to be used practically. There is strong evidence of a growing interest in the development and use of aerodynamic inverse design and optimization techniques. This is true, not only for aerospace industries, but also for any industries requiring fluid dynamic design. This clearly shows the matured engineering need for optimum aerodynamic shape design methodologies. Therefore, it seems timely to publish a book in which eminent researchers in this area can elaborate on their research efforts and discuss it in conjunction with other efforts.
Book Synopsis Subsonic and Transonic Drag Prediction of Single-element Airfoils Using Navier-stokes Solutions by : David D. Chao
Download or read book Subsonic and Transonic Drag Prediction of Single-element Airfoils Using Navier-stokes Solutions written by David D. Chao and published by . This book was released on 1996 with total page 156 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Drag Prediction and Decomposition for Airfoils and Wings by : David Dai-Wei Chao
Download or read book Drag Prediction and Decomposition for Airfoils and Wings written by David Dai-Wei Chao and published by . This book was released on 2004 with total page 348 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Author :National Aeronautics and Space Administration (NASA) Publisher :Createspace Independent Publishing Platform ISBN 13 :9781722496081 Total Pages :26 pages Book Rating :4.4/5 (96 download)
Book Synopsis Prediction of Airfoil Characteristics with Higher Order Turbulence Models by : National Aeronautics and Space Administration (NASA)
Download or read book Prediction of Airfoil Characteristics with Higher Order Turbulence Models written by National Aeronautics and Space Administration (NASA) and published by Createspace Independent Publishing Platform. This book was released on 2018-07-10 with total page 26 pages. Available in PDF, EPUB and Kindle. Book excerpt: This study focuses on the prediction of airfoil characteristics, including lift and drag over a range of Reynolds numbers. Two different turbulence models, which represent two different types of models, are tested. The first is a standard isotropic eddy-viscosity two-equation model, and the second is an explicit algebraic stress model (EASM). The turbulent flow field over a general-aviation airfoil (GA(W)-2) at three Reynolds numbers is studied. At each Reynolds number, predicted lift and drag values at different angles of attack are compared with experimental results, and predicted variations of stall locations with Reynolds number are compared with experimental data. Finally, the size of the separation zone predicted by each model is analyzed, and correlated with the behavior of the lift coefficient near stall. In summary, the EASM model is able to predict the lift and drag coefficients over a wider range of angles of attack than the two-equation model for the three Reynolds numbers studied. However, both models are unable to predict the correct lift and drag behavior near the stall angle, and for the lowest Reynolds number case, the two-equation model did not predict separation on the airfoil near stall. Gatski, Thomas B. Langley Research Center RTOP 505-59-50-05...
Book Synopsis Modeling Fluid Structure Interaction Over a Flexible Fin Attached to a NACA0012 Airfoil by : Srinivasa Ravindra Pantula
Download or read book Modeling Fluid Structure Interaction Over a Flexible Fin Attached to a NACA0012 Airfoil written by Srinivasa Ravindra Pantula and published by . This book was released on 2008 with total page 167 pages. Available in PDF, EPUB and Kindle. Book excerpt: Flow separation control is of importance to the performance of air vehicles. Generally, it is desired to postpone separation such that the overall drag is reduced, stall is delayed, lift is enhanced, and pressure recovery is improved. This work explores a new concept of post-stall flow control for airfoils and wings by using a thin flexible fin attached on the upper surface of an airfoil to passively manipulate flow structures in the fully separated flows for drag reduction and lift enhancement. The flow induced oscillations combined with the shape deformations change the overall pressure distribution on the fin, which in turn affect the fin dynamics. This mutual effect of inertial and elastic forces can also be considered through fluid-structure interactions (FSI). In order to study this problem a Navier-Stokes finite difference solver is coupled with a subdivision finite element solver in a segregated manner. The moving interface (i.e. fin) is modeled by a non-boundary conforming method called Immersed Boundary Methods (IBM). In the present dissertation validations for the Computational Fluid Dynamics (CFD), the Computational Structural Dynamics (CSD) and the Immersed boundary method (IBM) are presented. Then the coupled CFD-CSD solver is first used to model flow induced flapping flat plate with a 5[degree] angle of attack at Re = 20,000. Finally, the coupled solver is used to simulate flow over a NACA0012 airfoil with a passive flexible flapping fin attached to the upper surface of the airfoil with a 18[degree] angle of attack at Re = 63,000. The time averaged drag coefficient around the NACA0012 airfoil with the fin is computed at various angles of attack and compared with the baseline drag coefficient. The results show that the computations follow the experimental trend of drag reduction at higher angles of attack.
Book Synopsis Computational Prediction of Flow and Aerodynamic Characteristics for an Elliptic Airfoil at Low Reynolds Number by :
Download or read book Computational Prediction of Flow and Aerodynamic Characteristics for an Elliptic Airfoil at Low Reynolds Number written by and published by . This book was released on 2012 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Lifting surfaces of unmanned aerial vehicles (UAV) are often operated in low Reynolds number (Re) ranges, wherein the transition of boundary layer from laminar-toturbulent plays a more significant role than in high-Re aerodynamics applications. This poses a challenge for traditional computational fluid dynamics (CFD) simulations, since typical modeling approaches assume either fully laminar or fully turbulent flow. In particular, the boundary layer state must be accurately predicted to successfully determine the separation behavior which significantly influences the aerodynamic characteristics of the airfoil. Reynolds-averaged Navier-Stokes (RANS) based CFD simulations of an elliptic airfoil are performed for time-varying angles of attack, and results are used to elucidate relevant flow physics and aerodynamic data for an elliptic airfoil under realistic operating conditions. Results are also used to evaluate the performance of several different RANS-based turbulence modeling approaches for this class of flowfield
