In this study, flow and acoustic fields of a supersonic jet impinging on an inclined flat plate are investigated. Compressible Navier-Stokes equations are solved by a high-order shock capturing scheme with two different computational grids for investigating the effects of resolution for turbulent boundary layer. Total numbers of computational grids are 30 million and 700 million where a 700 million computational grid is designed for resolving turbulent boundary layer. From the near-wall flow fields, streak-like structures are observed in the case with a 700 million computational grid while such structures become unphysically big in the case with a 30 million computational grid. In spite of the difference in the resolution of turbulent boundary layer, essential flow and acoustic fields do not change for both cases. This indicates that flow and acoustic fields are insensitive to the resolution of turbulent boundary layer, and the mechanism of generation of aeroacoustic waves do not have strong relation with turbulent boundary layer.