Showing papers by "Rolls-Royce Motor Cars published in 1972"

Gas dynamic lasers

Abstract: In a high powered laser system it is proposed that combustion gases be bled off from a gas turbine engine and their composition adjusted by burning extra fuel in the bleed gases or adding extra substances. Suitable aerodynamic expansion produces a population inversion resulting in laser action in the CO2 species. Alternatively, bleed gases may be taken from the high pressure compressor of the gas turbine engine and an appropriate fuel burnt therein. If required, other adjustments may also be made to the composition and the resulting gaseous mixture subjected to aerodynamic expansion to induce laser action as before.

Air intake for a gas turbine engine

Abstract: The air intake lip of a gas turbine engine is made movable so as to make possible an increase in its contraction ratio. The movement is achieved in a manner which maintains the air intake throat area and position substantially constant, thus avoiding changes in air flow characteristics between the throat plane and compressor face.

Fluid flow blades

Abstract: An aerofoil-shaped blade for a gas turbine engine has longitudinally extending cooling fluid passages, and from each passage a group of transverse cooling fluid holes communicates with one of the outer surfaces of the blade. The holes are arranged to be relatively long so that the greater part of the heat transfer from the blade to the cooling fluid takes place in the holes.

The Prediction of the Optimum Performance of Ejectors

Abstract: A simple, incompressible flow, ejector model was formulated and analysed. It was found that the results obtained analytically agreed closely with those of an experimentally conducted optimization carried out by other workers. The model was also used to compare the relative merits of constant static pressure versus constant area mixing: it was shown that the latter was superior to the former when nozzle, mixing tube and diffuser friction losses were taken into account. The work also indicated that the efficiency of an ejector tends to increase as the secondary-to-primary stream density ratio decreases.

Air intake for a gas turbine engine

Abstract: A gas turbine engine air intake cowl has a displaceable lip member which, when cross winds develop, moves forwardly of the cowl to form a slot therebetween through which the cross wind passes and is guided onto that intake wall on the windward side of the intake so avoiding pressure losses and bad air distribution in the intake

Optical properties and orientation of thermally treated acrylic fibers

Abstract: Acrylic fibers containing methyl acrylate copolymer have been thermally treated in the temperature range 473°–573°K in an inert, oxygen-free environment. The optical properties and an x-ray diffraction orientation parameter have been studied in these fibers, with special attention to correlation with the essential chemical reactions and to the behavior of polymer chain orientation. Densification of the fibers, illustrated by specific gravity and refractive index changes during the thermal treatment, is interpreted as a more efficient packing of the polymer chains in addition to the development of more highly refractive and dense chemical species. An extrapolated value of refractive index of 1.70 for 100% nitrile polymerization supports the presence of naphthyridine structures. Birefringence changes from −0.003 to +0.27 imply a high degree of retention of the preferred orientation of polymer chains, despite the severe change in the chemical identity of the chains. The contrary behavior of the orientation parameter from the 100 arc of the x-ray diffraction of polyacrylonitrile as the thermal treatment proceeds indicates that the residual polyacrylonitrile sequences have reduced orientation.

Pitch varying mechanism for variable pitch fan

Abstract: The blades of a variable pitch fan of a gas turbine engine are rotated about their longitudinal axes as well as about the axis of the engine by a gear system which comprises a stationary actuator which initiates the pitch varying movement by producing a rotary output corresponding to the degree of pitch change required, an epicyclic differential gear driven by this output and the engine main shaft, and arranged to produce an output corresponding to the sum of the rotary output and the shaft rotational speed, and a pitch changing gear adapted to be driven by the output of the differential gear and to produce relative rotation of two annulus gears connected to rotate the fan blades about their own axes.

Method of applying a coating to a part

Abstract: The invention comprises a method of applying a coating to a steel part in which a coating of aluminium powder and organic resin is electrophoretically applied to the part, the coating is heated to drive off the resin, and the aluminium coating is impregnated with a high temperature resistant base material.

Valve for follow-up servo mechanism

Abstract: In a follow-up servo mechanism there is provided a valve having a part which can rotate and a part which is moved linearly. The valve forms part of a fluid flow path between a source of pressure fluid and a motor. The linearly movable part of the valve has slots in its surface inclined to the valve axis, the rotary part has bores communicating between the slots and the motor and is connected to the motor to move therewith. The arrangement is such that linear movement of the one part puts the source of fluid into communication with the motor through the bores and slots, the motor thus rotates and rotary movement of the rotary part of the valve connected to the motor takes the bores and slots out of communication and stops the motor in its new position.

Single Channel Constant Capacity Bulk Service Oueueing Process With An Intermittently Available Server

Abstract: This paper analyses a transient solution of a bulk service queueing problem wherein the arrivals follow a Poisson distribution, but the server is available in alternate, independently and exponentially distributed intervals with different means; except that, when the system is empty, he is available immediately to the arriving customer or customers in the bulk service case.

Annular combustion chamber with ceramic annular ring

Abstract: An annular combustion chamber for a gas turbine engine in which an annular wall part is made of a ring of ceramic material which is located in the chamber by compression between a frusto-conical first face and a second face which is radial or frusto-conical.

Liquid dispensing devices

Abstract: A liquid supply system comprising a rotatable housing for attachment to a variable pitch fan or propeller and to rotate therewith. The housing contains a pitch-control mechanism for the fan, and a quantity of lubricating oil sealed therein. The system includes a pump for dispensing the oil to the pitch control mechanism. The pump is connected to the periphery of the housing so as to receive at its inlet, during rotation of the housing, oil under centrifugal pressure and to dispense the oil radially inwardly to a point within the housing.

Variable Pitch Ducted Fans for STOL Transport Aircraft

Abstract: The Variable Pitch fan has a number of features which make it attractive as the basis for ultra-high bypass ratio ducted fans designed primarily for STOL aircraft. The variability imposes certain design constraints, particularly on fan pressure ratio, and leads to differences in engine geometry relative to equivalent fixed pitch engines. The merits of such engines are discussed under the headings of Performance, Noise, Engine Control, Thrust Modulation, Provision of Air Bleed for High Lift, Reverse Thrust and Development Flexibility.Copyright © 1972 by ASME

Epicyclic gear train

Abstract: An epicyclic gear train comprising a sun gear, a plurality of planet gears meshing with the sun gear and carried from a carrier rotatable about the sun gear axis, and an annulus gear conical with the sun gear and meshing with the planet gears, each of the gears having single helical teeth and the sun and annulus gears being axially displaced to reduce the tipping couple on the planet gears, drive being taken from or to the planet carrier solely on a plane or planes perpendicular to the rotational axis of the carrier and lying between the engagements between the planet gears and the sun gear, and the planet gears.

Method of etching a titanium or titanium alloy part

Abstract: The invention relates to a method of etching a titanium or titanium alloy part in which the part is immersed in a mixture comprising nitric acid, hydrofluorosilicic acid and water.

Measurements of the boundary layer growth in annular diffusers

Abstract: proper consideration must however by given to the added weight, reliability and cost factors. The data just presented covers Engine "A" with a relatively low tip speed fan. The next major step in the NASA/GE experimental Quiet Engine Program is to evaluate an engine incorporating Fan "C" which is representative of a high speed fan. Such an engine offers the advantage of having shorter length and fewer components, both of which permit important improvements in engine weight and engine cost. It is expected that the acoustic investigation of the Engine "C" technology demonstrator Will be pursued into the Spring of 1973. At that time comparable data will have been obtained on both "A" and "C" technology demonstrators and tradeoff studies will be performed to evaluate their relative merits acoustically and in terms of direct operating costs on a number of airplane applications. References

High temperature resistant coating

Abstract: A composition for coating steel components, such as the compressor parts of gas turbine engines consisting essentially of from two parts to half a part by weight of potassium silicate; from one part to two parts by weight of finely divided aluminum powder, from one quarter to three quarters of a part by weight of a polyhydroxy alcohol and sufficient water to produce a viscosity of up to and including forty seconds when measured on a British Standard number 4 flow cup at 20* C.

Reheat system for a gas turbine engine

Abstract: A reheat system for a gas turbine engine is provided with fuel supply means, a plurality of fuel manifolds having fuel distribution holes or nozzles located thereon, fuel/exhaust gas mixing means associated with each of the holes or nozzles and flame stabilisation means located downstream of the fuel manifolds. The mixing means are adapted in operation to tap exhaust gases from a portion of the reheat system, to mix the exhaust gases with fuel from their respective associated fuel nozzles or holes and exhaust the mixture into the combustion zone of the reheat system.

Pleochroism in thermally-treated acrylic fibres

Abstract: Acrylic fibres, coloured by inert thermal-treatments up to 573K are highly pleochroic. The preferred absorption is parallel to the fibre axis, implying that the chromophore is a molecular sequence intrinsically part of the oriented polymer chain. The biabsorption, k∥-k⊥, shows a direct correlation with amount of nitrile reacted in the polymer. Although the development of chromophore is directly related to polymerization of nitriles, the polymerized nitrile sequences themselves may not necessarily be the specific chromophore.

Turbofan Trends for Short Haul

Abstract: After a general indication of the noise problem the relation between conventional and STOL systems are broadly reviewed and their requirements as regards the powerplant are discussed. Some of the associated technical challenges are then considered. These include variable pitch fans, reduction gears, thrust reversal and the environment, (noise and pollution). It is shown that the development of a quiet, clean propulsion engine is perhaps the most important and pressing single task for the powerplant constructor to attack.Copyright © 1972 by ASME