40 operates to mix the two gas flows and communicate the mixed gas flow through the exhaust nozzles 30 36 at a relatively equal velocity in certain applications the mixing is helpful because the two gas flows are communicated at widely varying temperatures and pressures and by being combined together form a single homogenous flow of gases to reduce overall engine noise fig3 illustrates a core auxiliary duct passage 44 positioned within the core engine 28 the core auxiliary duct passage 44 is designed to increase the engine bypass ratio during certain operability conditions and thereby reduce engine noise as is further discussed below in one example the core auxiliary duct passage 44 extends circumferentially about the entire circumference of the core engine 28 in another example the core auxiliary duct passage 44 is an annular duct in yet another example the core auxiliary duct passage 44 includes a plurality of individual ducted passages disposed circumferentially about the engine centerline axis a it should be understood that the example core auxiliary duct passage 44 is not shown to the scale it would be in practice instead the core auxiliary duct passage 44 is shown larger than in practice to better illustrate its function a worker of ordinary skill in this art will be able to determine an appropriate duct passage volume for a particular application and thereby appropriately size the duct passage s 44 the core auxiliary duct passage 44 includes an inlet 46 and an outlet 48 in one example the inlet 46 is positioned upstream from the mixer section 40 in another example the inlet 46 is positioned on the core engine 28 between a.