Rolls-royce Corporation

Smiths Industries Public Limited Company

Roger C Witcomb

Peter A Stewart

Michael R Hawkesworth

Keith C Rawlings

Monitoring

A representation of oil flow in a gas turbine engine is obtained by injecting a compatible radioactive isotope label into the engine oil flow and detecting the radiation emitted from within the body with detectors mounted outside the body to produce signals representative of the quantity and direction of the radiation; the detector output signals are compensated for attenuation on passing through the engine in accordance with attenuation signals derived from a representation of the spatial distribution of the engine and of its materials, and signals from non-viable directions are discounted. The compensated detector output signals are used to generate a number of focal-plane tomograms from which an image in a desired plane may be re-constructed. The image may be formed on a background of the engine in the relevant plane generated from the representation thereof. The injection of radio-active label and the detector output signals may be pulsed to produce a strobed image from which velocity measurements can be obtained.

Method of and apparatus for analyzing fluid flows within hollow bodies

Carrier particles, e.g., of metal or metal oxide, are doped with a positron-emitting isotope and injected into fluid flowing in a body, such as a gas turbine engine. The positrons decay on coming to rest, giving two gamma rays which are detected, and a 3D image is built up. The particles are capable of stopping a portion of the positions before they escape from the particles into the surroundings; thus the gamma rays indicate more accurately the position at which the positron was emitted, and give a clearer image.

Growing community of inventors

Cheltenham, United Kingdom

Roger C Witcomb