Abstract: A gas flow separator for an annular combustion chamber of a gas turbine engine is disclosed in which the radially spaced apart first and second gas flow separator walls which extend axially into the combustion chamber from the combustion chamber upstream end wall each define a plurality of axially extending channels. Each of the channels extends generally axially in an upstream direction from the downstream edge of each of the separator walls such that their axial lengths are less than the axial lengths of the respective separator walls. Both the depth and the width of each of the channels increases from its upstream end point to the downstream edges of the separator walls. The channels may be circumferentially aligned with each other, or the channels of one separator wall may be circumferentially offset from the channels of the other separator wall.