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.

Acoustic scattering by density gradients

Abstract: In this paper we solve some model problems by the method of matched expansions and deduce some features of Green's function using the reciprocal theorem to demonstrate that scattering by density gradients can enhance the radiation efficiency of quadrupoles to that of dipoles. If a fluid is subjected to body forces close to and on both sides of a density interface, then the source system degenerates to a quadrupole only if the components of the forces perpendicular to the interface are equal in magnitude and opposite in direction and, additionally, the components of the forces per unit fluid density parallel to the interface are equal but opposite. In other cases dipole rather than quadrupole radiation efficiency is achieved. But we also show that, despite published assertions to the contrary, the radiation efficiency is not enhanced further and there is no monopole contribution to the radiated sound.

Gas turbine engines

Abstract: In a by-pass gas turbine engine having a lobed type by-pass air and turbine exhaust mixer unit, the reheat gutters are arranged in the mixer in the turbine exhaust duct. The gutters extend radially and are substantially Y-shaped, each of the two legs of the Y extending radially along the sides of a mixer lobe.

Seal release for a pressure vessel

Abstract: A seal has two portions, the first one of which is adapted to be sealingly secured to a cylindrical wall defining an aperture and the second one of which is adapted to sealingly engage the periphery of an object and is provided with means for varying its temperature so as to disengage the second portion from the periphery of the object.

Lift Jet Installational Experience

Abstract: A review of some of the progress made in lift jet installations is presented in this paper. At the heart of it all is the low cost lightweight RB162 second generation lift jet which is simple and makes extensive use of glass reinforced plastics. Examples of plastic components are shown. The higher thrust/weight and thrust/volume ratio of a third generation lift jet are revealed. The weight of installed features is of comparable importance to the weight of the basic engine. Installed weight has been reduced over three lift jet generations, more than keeping pace with the improvements in basic engine thrust/weight ratio. Weight breakdowns are given for the V.T.O.L. equipment in a fighter‐type aircraft representative of all three generations. Progress on lift intake and exhaust jet deflectors is shown with reference to specific examples. Ground erosion is briefly discussed and shown to be greatly reduced by multiple nozzles and the rolling take‐off technique. Progress being made on some of the problems associated with installing eight lift jets in a V.T.O.L. strike aircraft is briefly discussed with reference to maintenance and instrumentation.