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.

Development of a representative test specimen for frictional contact in spline joint couplings

Abstract: The frictional contact conditions in a helical spline joint coupling under torsional and axial loads are studied using finite element analyses. Comparisons of spline root torsional stresses are made with photoelastic measurements. Surface contact tractions, relative slip distributions and subsurface localized stress component and equivalent stress distributions are presented for both the external and the internal spline contact surfaces. The work is important as a basis for understanding and predicting the fatigue, contact fatigue, fretting fatigue, wear and fretting wear characteristics of the coupling. A representative test specimen concept is presented which seeks to capture the local contact variable distributions in the spline coupling, with a view to predicting the wear and the contact and fretting fatigue performance of the coupling.

A stator vane assembly for a turbomachine

Abstract: A stator vane assembly for a gas turbine engine (10) compressor (16) comprises a plurality of circumferentially arranged stator vanes (44A) and a plurality of circumferentially arranged load bearing struts (46). The leading edges (45,47) of the stator vanes (44A) and the struts (46) are arranged in a common plane. The leading edges (45,47) of the stator vanes (44A) and the struts (46) have substantially the same profile. The spacing (B) between adjacent struts (44A) in any group is the same. The spacing (C) between the suction surface (50) of one of the struts (46A) of the adjacent pair of struts (46) and an adjacent stator vane (44A) is less than the spacing (B) between adjacent stator vanes (44A) and the spacing (D) between the pressure surface (52) of the other of the struts (46B) of the adjacent pair of struts (46) and an adjacent stator vane (44A) is greater than the spacing (B) between adjacent stator vanes (44A) to equalise aerodynamic loading of the stator vanes (44A) and to reduce the aerodynamic losses of the struts (46).

On the Effect of Nb on the Microstructure and Properties of Next Generation Polycrystalline Powder Metallurgy Ni-Based Superalloys

Abstract: The effect of Nb on the properties and microstructure of two novel powder metallurgy (P/M) Ni-based superalloys was evaluated, and the results critically compared with the Rolls-Royce alloy RR1000. The Nb-containing alloy was found to exhibit improved tensile and creep properties as well as superior oxidation resistance compared with both RR1000 and the Nb-free variant tested. The beneficial effect of Nb on the tensile and creep properties was due to the microstructures obtained following the post-solution heat treatments, which led to a higher γ′ volume fraction and a finer tertiary γ′ distribution. In addition, an increase in the anti-phase-boundary energy of the γ′ phase is also expected with the addition of Nb, further contributing to the strength of the material. However, these modifications in the γ′ distribution detrimentally affect the dwell fatigue crack-growth behavior of the material, although this behavior can be improved through modified heat treatments. The oxidation resistance of the Nb-containing alloy was also enhanced as Nb is believed to accelerate the formation of a defect-free Cr2O3 scale. Overall, both developmental alloys, with and without the addition of Nb, were found to exhibit superior properties than RR1000.