Flow mixers particularly for gas turbine engines

Claim 1

A FLOW MIXER FOR MIXING INNER AND OUTER CONCENTRIC FLUID STREAMS BOUNDED BY AN OUTER GENERALLY CYLINDRICAL THIN-WALLED CASING AND SEPARATED BY AN INTERMEDIATE DUCT, SAID FLOW MIXER COMPRISING, INNER AND OUTER ANNULAR STRUCTURAL MEMBERS HAVING DUCTS DEFINING THE INNER AND OUTER BOUNDS OF SAID FLUID STREAM, SAID ANNULAR STRUCTURAL MEMBERS FURTHER COMPRISING RELATIVELY THIN RINGS EXTENDING FROM BOTH ENDS OF SAID DUCTS AND GENERALLY LONGITUDINAL STIFFENERS INTERCONNECTING SAID RINGS, THEREBY PROVIDING SAID ANNULAR STRUCTURAL MEMBERS WITH A MAXIMUM RIGIDITY TO WEIGHT RATIO IN RESISTING A DOUGHNUT MOMENT APPLIED THERETO, A PLURALITY OF STRUTS STRUCTURALLY INTERCONNECTIANG SAID INNER AND OUTER ANNULAR STRUCTURAL MEMBERS AT THE INLET AND OUTLET ENDS OF SAID FLOW MIXER, GENERALLY LONGITUDINAL PANEL MEANS INTERCONNECTING SAID INLET AND OUTLET STRUTS FOR PROVIDING LONGITUDINAL STIFFENING THEREOF AND SEPARATE FLOW PASSAGES THROUGH SAID MIXER, RAMPS EXTENDING FROM SAID INTERMEDIATE DUCT TO THE OUTER DUCT THROUGH CERTAIN PASSAGES FOR DISCHARGE OF THE INNER FLUID STREAM FROM THE FLOW MIXER AND OTHER RAMPS EXTENDING FROM SAID INTERMEDIATE DUCT TO THE INNER DUCT THROUGH OTHER PASSAGES FOR DISCHARGE OF THE OUTER FLUID STREAM FROM THE FLOW MIXER, WHEREBY THE FLUID STREAMS ARE DISCHARGED ACROSS THE FULL WIDTH OF THE FLOW MIXER OUTLET ANNULUS AND SAID FLUID STREAMS ARE INTERSPERSED AROUND THE CIRCUMFERENCE OF SAID OUTLET ANNULUS, SAID INNER ANNULAR MEMBER BEING ADAPTED TO RECEIVE GENERALLY AXIAL LOADS AND SAID OUTER ANNULAR MEMBER BEING ADAPTED TO MOUNT ON SAID CYLINDRICAL CASING, WHEREBY THE DEFLECTION OF SAID FLOW MIXER IN RESPONSE TO SAID LOADS ON SAID INNER CASING IS MINIMIZED AND THE LOADS ARE TRANSMITTED TO SAID CYLINDRICAL CASING IN SUBSTANTIALLY AN AXIAL DIRECTION.