| Summary: | 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.
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