Comparison of Higher Resolution Euler Schemes for Aeroacoustic Computaions

• Main Authors: Hu, Jeu-Jiun, 胡舉軍
• Other Authors: San-Yih Lin
• Format: Others
• Language: zh-TW
• Published: 1998
• Online Access: http://ndltd.ncl.edu.tw/handle/96210568244744733182

碩士 === 國立成功大學 === 航空太空工程學系 === 86 === A thesis is proposed to analyze and to develop a numerical methodfor aeroacoustics. It uses a fifth order accurate Weighted EssentiallyNon-Oscillatory(WENO)scheme and an explicit Runge- Kutta timeintegration method to solve the Euler equations. We test the accuracyof the WENO scheme on a linear equation. The results show that ithas about fifth order accuracy. Then we apply it on a traveling shockwave to compare the difference between the MOC and WENO scheme.It is concluded that the MOC is better then the WENO scheme. Next,a mean flow plus a small perturbation is calculated and the effects of several boundary conditions are discused. In this thesis, the shear layer instability is investigated. The shearlayer flow with Mach number M=0.5 and 0.9 are calculated to analyzethe temporal instability. Harmonic and subharmonic disturbances are introduced in the shear layer. One can found, initially introduced two vorticities, finally will be in paring together. For the M=0.9 case, a eddy shocklet is found in the flow field.