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.

Salt Template Assisted BN Scaffold Fabrication toward Highly Thermally Conductive Epoxy Composites.

Abstract: With the trend of device miniaturization and higher integration, polymer composites with high thermal conductivity are highly desirable for efficient removal of accumulated heat to maintain high performance of electronics. In this work, epoxy composites embedded with three-dimensional hexagonal boron nitride (BN) scaffold were fabricated. The BN-poly(vinylidene difluoride) (PVDF) scaffold was prepared by the salt template method using PVDF as the adhesive, while the corresponding epoxy composite was manufactured with vacuum-assisted impregnation. The epoxy/BN-PVDF composite exhibits high thermal conductivity with low loading of BN. The thermal conductivity of epoxy/BN-PVDF composite achieved 1.227 W/(m K) with 21 wt % BN, contributed by the constructed BN pathway held together by PVDF adhesive. In addition, PVDF could be further converted into carbon by thermal treatment, further enhancing the thermal conductivity of epoxy/BN-C composites through alleviating the phonon scattering at the interfaces, eventually obtaining thermal conductivity of 1.466 W/(m K). This type of epoxy-based composite with high thermal conductivity is promising to be used as thermal management materials in advanced electronic devices.

Gas turbine engine combustion chamber

Abstract: A gas turbine engine combustion chamber has primary and secondary combustion zones. An annular secondary fuel and air mixing duct surrounds the primary combustion zone. The annular secondary fuel and air mixing duct is defined at its radially outer extremity by an annular wall. The annular wall is at least partially formed by an annular manifold. The annular manifold has a number of radially inwardly extending fuel injectors which inject fuel into the secondary fuel and air mixing duct. The annular fuel manifold is mechanically isolated from the remaining portion of the annular wall by an annular gap. The annular fuel manifold is supported from the combustor casing by a fuel supply pipe which is secured to the combustor casing and the annular fuel manifold.

Staged gas turbine combustion chamber with counter swirling arrays of radial vanes having interjacent fuel injection

Abstract: Gas turbine engine combustion chamber has staged combustion to reduce nitrous oxides and includes a first radial flow swirler and a second radial flow swirler located axially of an annular mixing zone with each swirler having vanes for rotating the incoming air in substantially opposite directions relative to each other; first and second fuel injectors are provided with a first fuel injectors located in one of the passages of each of the first and second swirlers and with the second fuel injectors located upstream of the passages of the first and second swirlers.

Bladed ducting for turbomachinery

Abstract: An axial flow turbomachine has at least one circumferential row of aerofoil members in which at least one of the two end walls (33) between successive blades (30) is given a non-axisymmetric profile to modify the boundary layer flow at the wall. In one form of the profile, a convex region (33) adjacent each member pressure surface (35) and a complementary concave region (34) adjacent each member suction surface (34) extend over at least a major part of the blade chord lengths to reduce the transverse pressure gradient and thereby reduce vortical energy losses. In another form of the profile, at least one end wall (33) has complementary convex and concave regions (50,51) extending through the zone of the trailing edges of the members (30) on the suction end pressure surface sides (34,35) respectively of each member, thereby to reduce over turning of the flow. Both forms of profiling can be employed in combination.