The propagation of wave packet produced from a point source in two and three dimensional incompressible boundary layer is investigated numerically on the basis of linear stability theory.

There is a difference between the numerical simulation results of two-dimensional and three-dimensional flow field in supersonic inlet, which shows the influence of boundary layer on the side wall.

The boundary layer equations of vanes of centrifugal pump in two-dimensional incompressible fluid are set up and the relevant quantities are analyzed in the paper.