A series of experiment has been performed on the spray characteristics in a cylindrical confined space with various injection pressure taken as a parameter. By using the single-hole patternater and the Malvern particle sizer. The spatial distributions of mass flux, drop size and volume concentration were obtained along the radial and axial directions; The line-of-sight data by Malvern particle sizer was transformed to the ring-of-sight data by using the tomographical transformation. The experimental results show that, in the confined space, the entrainment of the ambient gas was restricted due to wall boundary, so that effective spray angle increased. Spatial drop size distributions decreased in the confined space, because very small drops resided in the recirculation zone and the breakup of drops by the drop-wall collision appeared.
