| Summary: | 碩士 === 國立成功大學 === 航空太空工程學系碩博士班 === 91 === In the recent year,the sence of environmental protection is on the increase,and the aero-noise problem is gradually emphasized.In this thesis,
the numerical computations are performed to investigate the flowfield and noise behaviors of the rotor blade.First,the unstructured tetrahedral meshes are created on the whole flow domain,then the two-/four-stage Runge-Kutta time integration schemes and a finite volume upwind method are adopted to solve the unsteady three-dimensional Euler equations in a rotating coordinate system.Meanwhile,an adaptive mesh technique is used to capture the vortexed sound wave.To evaluate the present solution procedure,the flowfield for a two-bladed rotor having the NACA0012 airfoil section in hover is studied on the coarse、fine and different adaptive meshes,and the computed surface pressure coefficient distributions on the rotor blade are compared with those in the related literatures.
Besides,the pressure and sound pressure level contours are introduced to understand the noise behaviors.Finally,the contours of pressure and sound pressure level are presented at the different time、span-wise locations and the strengths of line vortex.Those result indicate that the interaction noise between rotor blade and specified line vortex or tip vortex can be predicted on the adaptive meshes.
|
|---|
