I and II, in Applied Mathematics and Mechanics (Academic Press, London, UK, 1986). Blake, Mechanics of flow-induced sound and vibration, Vols. Kraichnan, Pressure fluctuations in turbulent flow over a flat plate, J. Hodgson, Trailing edge noise prediction from measured surface pressures, J. Howe, A Review of the theory of trailing edge noise, J. Roos, Resolution and structure of the wall pressure filed beneath a turbulent boundary layer, J. Curle, The influence of solid boundaries upon aerodynamic sound, Proc. Lamb, Hydrodynamics (Cambridge University Press, Cambridge, 6th ed., 1932). Amiet, Effect of the incident surface pressure field on noise due to turbulent flow past a trailing edge, J. Amiet, Noise due to turbulent flow past a trailing edge, J. Chase, Noise radiated from an edge in turbulent flow, AIAA J. Chandiramani, Diffraction of evanescent waves with applications to aerodynamically scattered sound and radiation from unbaffled plates, J. Hall, Aerodynamic sound generation by turbulent flow in the vicinity of a scattering half-plane, J. Chase, Sound radiated by turbulence flow off a rigid half-plane as obtained from a wavevector spectrum of hydrodynamic pressure, J. Marcolini, Aifoil self-noise and prediction (NASA RP 1218, 1989). The maximum camber position is also found to be important and its rear position increases noise levels on the suction side. However, a higher camber reduces low frequency noise on the pressure side. As airfoil thickness and camber increase, low frequency noise is increased. However, the effect of the airfoil shape on the maximum source region on the pressure side is negligible, except for the S831 airfoil, which exhibits an extension of the noise source region near the wall at high frequencies. As airfoil thickness and camber increase, the maximum source region moves slightly upward on the suction side. It is found that the dominant source region is around 40% of the boundary layer thickness for both the suction and pressure sides for a NACA0012 airfoil. The method is validated for a NACA0012 airfoil, and then five additional wind turbine airfoils are examined: NACA0018, DU96-w-180, S809, S822 and S831. This decomposition helps in finding the dominant source region and the peak noise frequency for each airfoil. In order to investigate the noise source characteristics, the wall pressure spectrum is decomposed into three components. The boundary layer profiles are obtained by XFOIL and the trailing edge noise is predicted by a TNO semi-empirical model. Your use of the translations is subject to all use restrictions contained in your Electronic Products License Agreement and by using the translation functionality you agree to forgo any and all claims against ProQuest or its licensors for your use of the translation functionality and any output derived there from.This paper investigates the effect of airfoil shape on trailing edge noise. PROQUEST AND ITS LICENSORS SPECIFICALLY DISCLAIM ANY AND ALL EXPRESS OR IMPLIED WARRANTIES, INCLUDING WITHOUT LIMITATION, ANY WARRANTIES FOR AVAILABILITY, ACCURACY, TIMELINESS, COMPLETENESS, NON-INFRINGMENT, MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE. The translations are automatically generated "AS IS" and "AS AVAILABLE" and are not retained in our systems. Neither ProQuest nor its licensors make any representations or warranties with respect to the translations. This functionality is provided solely for your convenience and is in no way intended to replace human translation. You have requested "on-the-fly" machine translation of selected content from our databases. Furthermore, with a higher Reynolds number, a higher angle of attack for the optimum lift-to-drag ratio as well a less camber is obtained. The results showed a faster convergence for the particle swarm optimization and the highest aerodynamic efficiency achieved by the 6-parameter method. Finally, a Reynolds number impact study is performed related to the airfoil shape and the angle of attack which maximizes the aerodynamic efficiency. A genetic algorithm and particle swarm optimization routines are developed and implemented in Matlab, also a sine-cosine algorithm is tested, where Xfoil and the open-source computational fluid dynamic software OpenFOAM are coupled with the optimization algorithms. This work employs the 4-digits NACA parameterization, a recently developed 6-parameters method, and the PARSEC technique with a correction of the matrices available in the literature, to compare the computational cost and the ability to achieved higher efficiency of these parameterizations. The aerodynamic efficiency in airfoil theory is defined as the ratio between the lift and drag force, which is the main objective function to be maximized in a wide kind of vehicle design due to its strong relationship between fuel consumption and range.
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