Abstract: A rotor blade 14 having a spar 138 and shell 134 is disclosed. Various construction details are developed for efficiently transferring rotational loads on the rotor blade to the root section 28 of the spar. The spar has a projection 139 over which extends a portion 100 of the shell and a platform 36 of the rotor blade.

Abstract: A rotor assembly 10 having a coolable rotor blade 14 for a gas turbine engine is disclosed. Various construction details are discussed which enable the rotor blade to satisfy the aerodynamic requirements of the engine and the requirements of fatigue life for the rotor assembly. The rotor blade includes a spar 38 and a shell 34 which extends chordwisely beyond the root 42 of the spar. In one embodiment, an axis of symmetry A.sub.r of the root of the spar is parallel to the axis of rotation A of the rotor assembly.

Abstract: A coolable rotor blade 14 for an axial flow rotary machine and a method for making the rotor blade are disclosed. The rotor blade includes a spar 38 and a shell 34 for defining the airfoil surface of the rotor blade. A platform 36 extends over the shell and the spar. The spar has a root 42 and an airfoil section 40. The shell is spaced from the spar and is joined to the airfoil section of the spar for defining cooling passages in the blade. The shell and the platform are each attached to the spar for support against rotational force. The method includes the steps of joining a shell to the airfoil section of the spar which extends over a portion of a projection 139 on the spar and forming a platform about the spar and the shell such that the platform is attached to the spar and extends over the projection and a portion of the shell. In one embodiment, the spar is formed of a first material, the shell of a second material, and the platform a third material.

Abstract: A free standing, continuous seal ring 54. The seal ring is effectively circumferentially continuous. The seal ring is adapted to extend between two circumferentially extending structures 38, 42. The structures 38, 42 separate a region 46 having a first pressure from a region 44 having a lower pressure. The seal ring is formed of two elements: a first element 78 having a circumferential gap G; and, a second element 80 extending across the gap G. Various construction details which enhance the efficiency of the seal ring are disclosed. In one particular embodiment, the second element is nested within the first element.

Abstract: The acoustic treatment for low frequency noise reduction is improved upon in a deep backing cavity lining configuration by providing a depending member or lip at the entrance extending into the cavity defining a space for supporting a column of air for increasing the mass reactance with a resulting decrease in the cavity depth without sacrificing sound attenuation. A slotted construction provides the smallest width of surface opening in the direction of air flow minimizing aerodynamic losses.

Abstract: A system for varying the acoustic resistance of an acoustical lining disposed in a duct of an air propulsor comprises a nonlinear sound suppression liner having a porous facing sheet overlying a plurality of cells, header means communicating with each of the cells and air pumping means for forcing a predetermined steady flow of air sequentially through the header means, the cells and the facing sheet to vary the acoustic resistance of the facing sheet to make it optimum for a selected sound level and airflow condition in the duct.