Rolls-Royce Motor Cars

About: Rolls-Royce Motor Cars is a based out in . It is known for research contribution in the topics: Turbine & Gas compressor. The organization has 3845 authors who have published 4934 publications receiving 58973 citations. The organization is also known as: Rolls-Royce Motor Cars Limited.

A holistic system approach for short range passenger aircraft with cryogenic propulsion system

Abstract: Currently, hybrid-electric aircraft are under investigation as one possible solution to reduce the emissions of the aviation industry according to Flightpath 2050 of the European Union. To meet the drive trainʼs requirements on low mass while aiming for highest efficiency, superconducting technologies are regarded as a key enabling technology for drive train powers of several tens of megawatts. Within the German nationally funded project TELOS an exemplary mission profile and the physical measures of a 220-passenger aircraft are used to derive the requirements for a cryogenic-cooled serial hybrid-electric propulsion system. To optimize the total system performance, we subsequently evaluated the superconducting and cryogenic-cooled components by using computationally fast, analytical models. This approach allows quantifying the system performance by using component technologies being available today. In particular, the system performance of geared drive to direct drive propulsion units are compared and the influence of the DC bus voltage and the electric frequencies of the AC circuits on the mass and the efficiency of the drive trains are analysed.

Modelling of Pressurised Hybrid Systems Based on Integrated Planar Solid Oxide Fuel Cell (IP-SOFC) Technology

Abstract: This work describes different models, developed by the Thermochemical Power Group at the University of Genoa (Italy), for the simulation of solid oxide fuel cell and gas turbine hybrid systems. The paper focuses on both “cores” of the system: the fuel cell stack on the one hand and the turbomachinery and the auxiliaries on the other hand. Therefore, in the first part of the paper the models developed for the analysis of the Rolls-Royce Integrated Planar SOFC cells are presented; the results are compared to experimental data, and carefully analysed and discussed. In the second part of the paper, design and off design models of IP-SOFC pressurised hybrid systems in the range 250 kW–20 MW are presented; the hybrid performance results are presented and discussed, also taking ambient condition effects and a possible control strategy into account. Finally, using an in-house general purpose transient system analysis code (TRANSEO code), where chemical composition, heat transfer, and fluid dynamic influences vs. time are considered in detail, a preliminary time dependent investigation of a pressurised hybrid system behaviour is presented.

Surface finishing on IN625 additively manufactured surfaces by combined ultrasonic cavitation and abrasion

Abstract: The poor and non-uniform surface quality of parts produced by powder bed fusion (PBF) processes remains a huge limitation in additive manufacturing. Here we show that ultrasonic cavitation abrasive finishing (UCAF) could improve the surface integrity of PBF surfaces built at various orientations –0°, 45° and 90°. Average surface roughness, Ra, was reduced from as high as 6.5 μm on side surfaces (90°) to 3.8 μm. Surface morphological observations showed extensive removals of surface irregularities and peak reduction on sloping (45°) and side surfaces. The micro-hardness of the first 100 μm of the surface layer was enhanced up to 15 % post-UCAF. Dimensional changes were minimal and uniquely dependent on the initial surface characteristics. A parametric study further showed the effect of abrasive size, abrasive concentration, ultrasonic amplitude and working gap on UCAF’s performance. A moderate abrasive size at 12.5 μm and concentration level at 5 wt% resulted in the lowest final Ra; as the two dominant material removal mechanisms – direct cavitation erosion and micro-abrasive impacts – were balanced. Finally, UCAF was demonstrated to result in 20 % Ra improvement of internal surfaces of a 3 mm diameter channel.