Rolls-Royce Holdings

About: Rolls-Royce Holdings is a company organization based out in Derby, United Kingdom. It is known for research contribution in the topics: Turbine & Gas compressor. The organization has 4027 authors who have published 6305 publications receiving 80517 citations. The organization is also known as: Rolls-Royce Holdings plc.

Stall Inception and Development in an Axial Flow Aeroengine

Abstract: This paper describes the phenomenon of stall and surge in an axial flow aeroengine using fast response static pressure measurements from the compressor of a Rolls-Royce VIPER engine. It details the growth of flow instability at various speeds, from a small zone of stalled fluid involving only a few blades into the violent surge motion of the entire machine. Various observations from earlier theoretical and compressor rig results are confirmed by these new engine measurements. The main findings are as follows: (1) The point of stall inception moves rearward as engine speed increases, and is shown to be simply related to the axial matching of the compressor

Fan or compressor casing

Abstract: The surge margin of a fan or compressor stage may be increased by radial, circular grooves in the casing ( 2 ) encircling the rotor stage. The present invention provides improved aerodynamic performance by replacing circumferential grooves by multiple helical grooves 18 . Preferably the grooves ( 18 ) have multiple start and end positions ( 20,22 ) spaced apart around the casing ( 2 ) and at least the downstream ends ( 22 ) of the grooves ( 18 ) are tapered to aid expulsion of particles in the grooves ( 18 ).

Apparatus and a method for testing attachment features of components

Abstract: An apparatus ( 10 ) for testing attachment features ( 26,28,30,32 ) of components ( 12,14 ) comprises a first member ( 16 ) having a first end ( 18 ), a second end ( 20 ), a first edge ( 22 ) and a second edge ( 24 ). The first edge ( 22 ) has a first firtree slot ( 26 ) to receive a first component ( 12 ) and the second edge ( 24 ) has a second firtree slot ( 28 ) to receive a second component ( 14 ). The first component ( 12 ) has a firtree attachment feature ( 30 ) to fit the first slot ( 26 ) and the second component ( 14 ) has a firtree attachment feature ( 32 ) to fit the second slot ( 28 ). The first end ( 18 ) of the first member ( 16 ) has flanges ( 34,36 ) extending laterally and the second end ( 20 ) of the first member ( 16 ) has flanges ( 38,40 ) extending laterally such that the first member ( 16 ) is substantially H-shaped in cross-section. First load means ( 42 ) apply a load on the first component ( 12 ) and second load means ( 44 ) apply a load on the second component ( 14 ) substantially in the opposite direction to the load on the first component ( 12 ). The apparatus may be used to test firtree attachments for turbine blades and discs.

Multifidelity Multidisciplinary Whole-Engine Thermomechanical Design Optimization

Abstract: Traditionally, the optimization of a turbomachinery engine casing for tip clearance has involved either two-dimensional transient thermomechanical simulations or three-dimensional mechanical simulations. This paper illustrates that three-dimensional transient whole-engine thermomechanical simulations can be used within tip clearance optimizations and that the efficiency of such optimizations can be improved when a multifidelity surrogate modeling approach is employed. These simulations are employed in conjunction with a rotor suboptimization using surrogate models of rotor-dynamics performance, stress, mass and transient displacements, and an engine parameterization.

Erosion of EB-PVD thermal barrier coatings

Abstract: Thermal barrier coating manufacture is based on two different processing technologies, namely thermal spraying and electron beam physical vapour deposition (EB-PVD) of a yttria stabilised, zirconia ceramic. The former is widely used to deposit ceramics on combustor cans, ductwork, platforms and other hot gas path components. The latter, due to its unique columnar structure, is the only process that can offer satisfactory levels of spall resistance, erosion resistance and surface finish retention for aerofoil applications. By using a unique high velocity gas gun rig, that has been developed with the capability of impacting thermal barrier coatings at particle velocities upto 300m/s at test temperatures up to 920°C, this paper contrasts the erosion behaviour of an APS and EB- PVD ZrO2−8wt%Y2O3 ceramic. When subjected to room temperature erosion using 100μm Al2O3, the erosion rate of an EB-PVD thermal barrier ceramic was observed to be an order of magnitude lower than its plasma sprayed counterpart. At high ...