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.

Blade-tip heat transfer in a transonic turbine

Abstract: The blade-tips of high-pressure turbine blades in a gas turbine engine are subjected to strong convective heat transfer and continued to present a significant design challenge to manufacturers. This paper is concerned with developing an understanding of the unsteady flow physics that influences the blade-tip heat transfer. Experimental investigations of blade-tip heat transfer and aerodynamics have been conducted in a transonic turbine stage test facility. The data reveal the effect of vane-rotor interactions on the unsteady heat transfer along the blade-tip mean camber line. In particular, the vane shock and potential field interaction establish characteristic unsteady heat transfer signatures at different axial positions along the blade-tip. The fluctuations in heat transfer are discussed in terms of vane-periodic changes in both relative total temperature and aerodynamic conditions.

Inlet particle separator

Abstract: To prevent dust and other debris from entering the compressor (12) of a gas turbine engine (10) an inlet particle separator (30) is provided. Air contaminated with dust and debris is induced into a scavenge chamber (32). An exhaust vent (35) is provided from the scavenge chamber (32) through which the contaminated air is ejected to atmosphere. Flow dividers (40,42,44) are positioned in the scavenge chamber (32) to ensure that the flow into the chamber is uniform around the inlet passage.

Compositional prediction of creep rupture life of single crystal Ni base superalloy by Bayesian neural network

Abstract: The creep rupture lives of single crystal Ni base superalloys are predicted as a function of alloy composition, creep stress, and creep temperature. A database has been constructed from previous publications and the Rolls-Royce materials database. The Bayesian neural network technique was used for the modelling of creep rupture life. To obtain the posterior distribution and prediction which is of a high dimensional integral form, the Markov chain Monte Carlo method was applied. With a complex 13-31-1 architecture, the neural network shows a precise prediction of creep rupture life of superalloys. Automatic relevance determination reveals that the influences of Re and Cr on creep rupture life of single crystal superalloys are the greatest amongst the alloying elements.

Hydrodynamic Physical Modeling of Laser Drilling

Abstract: Laser drilling is a complex process that involves material removal through both vaporization and hydrodynamic melt ejection. The process is further complicated when an assist gas is incorporated, which is often the case under most practical drilling conditions. It is the intent of this article to investigate these effects through both experiments and theoretical analysis. The analysis accounts for conduction in the solid, vaporization, vaporization-induced recoil pressure melt ejection, convection due to the melt flow as well as the effects of using an O 2 assist gas, which includes the effective assist gas pressure exerted on the melt surface, the forced convection cooling and the additional energy generated due to the oxidation of the melt surface by O 2 . The effects of the absorbed laser intensity on the melt surface temperature, melt ejection velocity and drilling velocity were .studied for both cases of laser drilling with and without O 2 assist gas and compared to experimental results obtained for EN3 low carbon steel. The dependence of threshold time on the absorbed laser intensity for either vaporization-dominated or melt ejection-dominated (hydrodynamic-dominated) material removal was studied and subsequently related to the threshold conditions for spatter formation. The model was subsequently optimized by examining the significance of the O 2 effects considered.