Rolls-Royce Limited

About: Rolls-Royce Limited is a based out in . It is known for research contribution in the topics: Gas compressor & Rotor (electric). The organization has 624 authors who have published 623 publications receiving 10751 citations. The organization is also known as: Rolls Royce Limited.

Detection of changes in transparency of optical elements

Abstract: In a radiation pyrometer in a gas turbine engine, non-uniformly distributed changes in transparency of an optical element in the system, e.g. contamination of pyrometer objective lens L 1 by combustion products from the turbine can be automatically detected. Lens L 1 focusses radiation from target T onto an additional lens L 2 , which in turn focusses it onto the end E of the fibre-optic bundle F. Considered reciprocally, lens L 2 images the end E of fibre-optic F into L 1 , so that although each optical fibre in end E receives radiation from all parts of target T, each fibre is imaged into a corresponding discrete area of L 1 . Fibre-optic bundle F comprises two (or more) sub-bundles F 1 and F 2 forming complementary sub-areas of end E and each sub-bundle is provided with its own photodetector P 1 , P 2 and associated pre-amplifier A 1 ,A 2 adjusted so that their outputs A 1 S 1 and A 2 ,S 2 are matched at the non-contamination condition. When one part of lens L 1 is contaminated during service more than the other parts, this will show as an unacceptable mis-match between the outputs A 1 S 1 and A 2 S 2 . This is automatically detected by differential amplifier D whose output gives a warning indication and can also be used to trigger a selector circuit X to select the strongest signal for onward transmission.

Method of and apparatus for analyzing gas flows inside hollow bodies

Abstract: In order to produce a visual image on a screen of the movement of gas flows inside hollow bodies, e.g. gas turbine or internal combustion engines, or wind tunnels, a gaseous tracer material including a short-lived radio-active isotope is injected into the hollow body. Radiation detectors 32 are positioned around a gas turbine engine 10 and linked to a computer 36 which is programmed using an image reconstruction algorithm to reconstruct the flow path of the isotope in suitable form. One suitable isotope is produced by irradiating carbon tetrafluoride using a stream of deuterons from a cyclotron 12. The resulting reaction produces an isotope of Fluorine which has a half-life of 11.56 seconds, and decays producing radiation at approximately 1.6 Mev. The activity of the isotope is raised to the highest feasible level by continuously irradiating the tracer material in a chamber 14 as it is pumped around a circuit prior to injection. The half lives of the isotopes used are in the range 3 seconds to 2 minutes.

Method of manufacture of articles with internal passages therein and articles made by the method

Abstract: In casting of hollow turbine blades problems arise with breakage or distortion of long thin cores for small diameter cooling passages, and also in maintaining cores accurately positioned for casting thin walled blades. The present invention provides a method of manufacture in which a pre-form of the blade, or other hollow article, is made in two parts and is accurately machined to define the required passage shapes or wall thicknesses in at least one of the parts, appropriate cores are made and the pre-form parts are assembled in a casting mould with the cores in position and heated to melt the preforms. Thus the cores are supported by solid material during the melting process. The melting can take place progressively in a uni-directional manner along the article so that only a narrow area of the article becomes melted at any time and the cores are supported in the melt from both ends. Thus columnar grained or single crystal articles can be made by this method. The method can also be used to produce blind-ended holes in a cast article.

Mounting arrangements for combustion equipment

Abstract: The combustion equipment of a gas turbine engine comprises an annular flame tube and a support casing both subjected to relatively high temperatures. Engine acceleration or engine deceleration causes the temperature in the combustion equipment to increase or decrease respectively, and this results in either expansion or contraction of the annular flame tube and the support casing. The annular flame tube has a greater rate of thermal expansion/contraction than that of the support casing and this results in distortion or cracking of the combustion equipment if the annular flame tube and support casing are rigidly mounted to each other. To overcome this problem a relatively flexible support structure which has a generally U-shaped cross-section is positioned radially between the annular flame tube and the support casing, and a first limb of the flexible support structure is secured to the annular flame tube and a second limb of the flexible support structure is secured to the support casing, and the flexible support structure permits relative radial movement of the annular flame tube and the support casing.

Fluidized bed combustion apparatus

Abstract: A fluidized bed combustion apparatus comprises a vessel in which a bed of fluidizable combustible and inert materials is supported, an inlet for a flow of fluidizing and combustion gas, an outlet for a flow of heated gas and gas swirling means located in the vessel between the fluidizable bed and the vessel outlet, the function of the gas swirling means being to retain any unburnt or only partially burnt materials in the vessel until combustion is complete.