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.

Microstructure and microhardness of Ti6246 linear friction weld

Abstract: The microhardness and microstructure of linear friction welded Ti–6Al–2Sn–4Zr–6Mo (Ti6246) alloys were studied, in both as-welded and post-weld heat-treated conditions. It has been found that the as-welded Ti6246 has a lower microhardness value of about 360 HV in the central weld zone than that of the base material of about 420 HV. Post-weld heat-treatment of the Ti6246 weld at 600 °C for 1 h has led to the hardness increase of about 180 HV at the central weld zone. Transmission electron microscopy studies show that the microstructure at the central weld zone of the as-welded Ti6246 consists of fine grains with dense acicular orthorhombic α″ martensite. The soft α″ martensite is believed to account for the low hardness measured in the as-welded conditions. Phase transformation from orthorhombic α″ to hexagonal α occurred during the PWHT, resulting in the observed hardness increase.

Compressor having casing treatment slots

Abstract: A compressor ( 16 ) comprises a rotor ( 40 ) having a plurality of circumferentially spaced radially outwardly extending rotor blades ( 42 ). A casing ( 44 ) surrounds the rotor ( 40 ) and rotor blades ( 42 ). The casing ( 44 ) has an inner surface ( 48 ) and a plurality of circumferentially spaced slots ( 50 ) are provided in the inner surface ( 48 ) of the casing ( 44 ). Each slot ( 50 ) has a length (L), a depth (D), a width (W), an angle (θ) of inclination relative to the radial direction, an axial position (AP) relative to the rotor blades ( 42 ) and a circumferential position (CP) relative to an adjacent slot ( 50 ). The slots ( 50 ) are arranged such that at least one of the length (L), depth (D), width (W), angle (θ) of inclination relative to the radial direction, axial position (AP) relative to the rotor blades ( 42 ) and circumferential position (CP) relative to an adjacent slot ( 50 ) varies circumferentially around the casing ( 44 ).

Variable guide vane arrangement for a compressor

Abstract: A variable guide vane arrangement includes a control ring located in a fixed axial position and an operating lever having a first end and a second end which is secured to the control ring with the first end positioned between two flanges and secured thereto by a pin; the second end is connected to a portion which fits into a bore and is slidable with respect thereto to vary the length of the operating lever

Method of manufacturing an article, a method of diffusion bonding and a vacuum chamber

Abstract: A stack of titanium sheets are placed between a pair of pressurizable chambers in a vacuum chamber. One of the mating surfaces of each pair of mating surfaces has had a stop off material applied in a desired pattern to prevent diffusion bonding. A pump evacuates the vacuum chamber and heaters heat the stack to evaporate volatile binders from the stop off. When all the binder has been removed the stack is heated and the pressure in the pressurizable chambers is increased to cause a pair of resilient members to apply pressure on the stack to diffusion bond the sheets together. The volatile binder is removed quickly and oxidation of the titanium is prevented during baking out of the binder. The integral structure is then heated and internally pressurized to superplastically form one of the sheets to produce an article of predetermined shape. No welding of the sheets before bonding is required.

Combustion chamber for a gas turbine engine

Abstract: A combustion chamber for a gas turbine engine has a wall which is provided with rows of apertures. The apertures are arranged so that the axes of the apertures form an angle of between 25° and 35° with respect to the inner surface of the wall. The apertures have a first cylindircal portion and a second divergent portion to produce fan shaped apertures. An upstream portion of the wall has apertures arranged in axially spaced groups, each of which has three rows of apertures and a downstream portion of the wall has apertures arranged in axially spaced groups, each of which has two rows of apertures. The axes of adjacent apertures in each row are spaced apart by at least three times the diameter of the cylindrical portion. The apertures produce effective film cooling of the wall using less cooling air than conventional cooling rings. The apertures may be arranged locally to cope with hot spots.