Numerical Investigations On Wing-winglet Aerodynamic Performance

• Main Authors: Bae-Yih Hwang, 黃百毅
• Other Authors: San-Yih Lin
• Format: Others
• Language: zh-TW
• Published: 1995
• Online Access: http://ndltd.ncl.edu.tw/handle/98288339058329380304

碩士 === 國立成功大學 === 航空太空工程學系 === 83 === A paper is proposed to investigate the aerodynamic performa- nce of transonic wings with or without using numerical methods. For the numerival methods, efforts are intended to develop and to test a finite volume method for solving the solution of the three-dimensional compressible Euler equations. The finite volu- me method uses a third-order Modified Osher-Chakrovarth upwind explicit Runge-Kutta time integration with an implicit residual smoothing for time discritization. In the present study the three-dimension flows about the ON- EAR M6 wingand the NACA0012 wing are used as tests for estimati- ons. Results of the computer code developed to calculate three- dimensioncompressible flow compare well with the exprimental da- ta and the results existin codes where available. In the model study, the work emphasizes the investigations the pressure distribution of transonic wings at Mach number bet- ween 0.75 and 0.85, and the effects of the areodynamic performa- nce with the device of winglet. The main scope of the work to s- tudy the effects of using upwind extrapolations and limiter fun- tion to the numerical results, and to study the aerodynamic per- formance of the wings and the vortex flowfield downstream of the wing tip. The numerical results show that the winglet reduces t- he drag coefficients and increased th lift coefficients. The wi- ngtip pressure coeficients become more negative on the aft regi- on of the upper surface and more positime ont the lower surface because of the winglets . The tip vortex was delayed due to the winglet and reduced the strengh of tip vortex.