A dirt separator assembly for a gas turbine engine comprises a cyclonic accelerator in flow communication with compressor discharge air, the accelerator having a plurality of passages, each passage having an inlet, an outlet and at least one vent located in the passage, a plurality of turning vanes disposed along each of the passages, the passage turning tangentially between the inlet and the outlet, the accelerator passages decreasing from a first cross-sectional area to a second cross-sectional area and said turning vanes inducing helical swirl of compressed cooling air, and, at least one vent located in the accelerator passages for expelling dust separated from the swirling compressed cooling air.