Rolls-Royce Limited

About: Rolls-Royce Limited is a based out in . It is known for research contribution in the topics: Gas compressor & Rotor (electric). The organization has 624 authors who have published 623 publications receiving 10751 citations. The organization is also known as: Rolls Royce Limited.

Constraint relationships in linear and nonlinear finite element analyses

Abstract: Finite element analysis of engineering structures commonly requires the use of inter-nodal displacement constraints. Current algorithms for this facility—elimination, Lagrange multipliers and penalty function methods—are briefly reviewed. An alternative approach is proposed which avoids some of the problems of these methods. This technique uses solution of the unconstrained stiffness equation with an extended number of right-hand sides. The resulting solutions are then combined to satisfy the constraints. This method has application in the synthesis of sub-structures with incompatible boundary variables. It is particularly efficient when the constraint affects many variables but the kinematics of the constraint can be expressed in terms of few independent variables, e.g. rigid body motion of part of the structure. In common with the Lagrange method, it produces data for use in a nonlinear analysis with constraints. The formulation of ‘rigid body’ constraints in geometric nonlinearity is detailed and demonstrated.

Gas turbine engine power plant

Abstract: A ducted fan propulsion plant has a reversible-pitch fan driven by a core gas turbine engine and housed in a duct which terminates at its downstream end in an outlet nozzle defined between two semi-cylindrical shells. The shells are mounted for movement hydraulically both axially and angularly to define an increased effective nozzle area for take-off. Upon further rearward axial displacement the shells adopt a reverse-thrust position to define air inlets to the fan when the fan blade pitch is reversed.

Nozzle guide vane structure for a gas turbine engine

Abstract: A nozzle guide vane assembly for a gas turbine engine comprises inner and outer porous sheet metal platform rings and a plurality of aerofoils extending between the rings, each of the aerofoil portions having mounting means at its inner and outer extremities by which the aerofoils, and thus the rings, are supported from fixed engine structure.

Cooled shroud for a gas turbine engine

Abstract: A cooled shroud for a gas turbine engine comprises an annular metallic supporting member having holes therethrough for the flow of cooling air and a layered coating on its inner face The layered coating comprises a first layer of porous material through which the cooling air may permeate, and a second layer of impermeable ceramic covering all but selected areas of the surface of the first layer In this way the cooling air is largely constrained to flow along the porous material to provide good cooling with relatively low air flow

Vane or blade for a gas turbine engine

Abstract: A cooled vane or blade for a gas turbine engine comprises a hollow shell with chordwise internal fins which support an air entry tube. The tube receives cooling air from outside the vane and is apertured to allow the air to flow toward the leading and trailing edges of the blade. The trailing edge of the blade is slotted longitudinally to allow the cooling air to escape, and pedestals interconnect the two flanks of the trailing edge portions. Film cooling holes are provided at various locations on the blade.