Abstract: A heat exchanger having first and second ducts respectively for the supply of compressed air to be heated and for the discharge of heated compressed air. A tube matrix includes first and second branches respectively connected to the first and second ducts for conveying compressed air from the first duct to the second duct. The tube matrix is exposed to the flow of hot gases therearound to heat the compressed air conveyed in the tube matrix. A plate heat exchanger connects the first and second branches of the tube matrix to convey the compressed air from the first branch to the second. The plate heat exchanger is formed by spaced plates between which the hot gases flow, each plate being connected to rows of tubes of the matrix in the first and second branches and forming a flow chamber in which the compressed air can be conveyed.

Abstract: The hollow shaft of a high pressure compressor is provided in a conically tapering section downstream of the last rotor disc on its inner surface with a vane-like rib arrangement for conveying a stream of cooling air from the vicinity of the axis of the shaft into the outer peripheral regions of the last rotor disc. The stream then passes through corresponding circumferentially distributed axial holes in the rotor disc. In this way, better cooling of the last compressor stages which have been heated by the main stream of air in the compressor and a reduction in the stresses in the structural parts can be obtained.

Abstract: A heat exchanger having an inlet duct for admission of a first fluid to be heated, an outlet duct for discharge of the first fluid after heating thereof, the ducts being arranged in substantially parallel relation, and an assembly of a plurality of heat exchanger tubes connected to the inlet and outlet ducts for receiving the first fluid from the inlet duct to convey the first fluid through the tubes for discharge into the outlet duct. The heat exchanger tubes are of U-shape, each including first and second straight leg portions respectively connected to the inlet and outlet ducts and a curved bend region connecting the straight leg portions for reversing the direction of flow of the first fluid from the first leg portion to the second leg portion. The assembly of heat exchanger tubes projects laterally of the ducts into the path of travel of a second fluid which flows around the tubes in a passage area.

Abstract: A method and apparatus for optimizing the radial clearance of rotor and stator vanes with their opposed structure for axial flow compressors of gas turbine power plants in which rotor disks are vented and thermally controlled by compressed air taken from the main flow path in the compressor via openings in the inner surface of the main flow path at one or more of the compressor stages. The removed air is supplied to annular spaces formed between rotor and/or seal support disks.

Abstract: The conical section of the hollow shaft of a high pressure compressor behind the last rotor disc is surrounded by an annular protective shield. The shield serves to protect the hollow shaft and the last rotor disc from the main stream of hot compressed air leaving the compressor. Between the hollow shaft and the heat shield a stream of cooling air is furthermore conducted from the vicinity of the axis to the outer region of the last rotor disc. The stream of air then passes through corresponding circumferentially distributed axial holes in the last rotor disc.

Abstract: A brush seal for first and second spaced, adjoining members which are capable of undergoing universal relative displacement, the seal comprising a plurality of flexible bristles having opposite ends, one of which is secured in a clamp causing the bristles to fan outwardly towards the other end. The second member supports a joint defining a space with a throat into which the fan of bristles enter and are resiliently squeezed at the throat. The free ends of the bristles are spaced for free movement in the joint lengthwise of the bristles to accommodate relative movement of the members towards and away from one another. Relative movement of the members longitudinally in their respective planes in taken up by sliding of the bristles within the joint while relative movement of the members transversely in their respective planes is taken up by bending of the bristles at the throat. In the case of all relative movement of the members, the bristles maintain sealing contact with the joint at the throat.

Abstract: A turbo-engine constructed to maintain the radial gap between the rotor and casing. The casing of the engine includes an inner casing having shell-shaped parts with centering seats and adjacent parts are secured a given distance apart axially.Each shell-shaped part comprises a plurality of angular segments which are secured together by fasteners aligned in a plane extending perpendicularly to the axis of rotation of the rotor.

Abstract: A shaped tube with an elliptical cross-section with a multichamber design for tubular heat exchangers is provided with at least two cross ribs passing through an interior space of the tube at a distance from one another. A method for making this tube provides for bending an endless metal strip into two semifinished products with congruent profiles. Each profile has the shape of an isosceles triangle with rounded vertices and an elongated leg. The semifinished products are then placed against one another so that the free end of the elongated leg of one semifinished product abut the triangle base edge of the other semifinished product.

Abstract: A tube connecting device is provided that connects rectangular tube ends in a fluid-tight manner with one another. The tube ends communicate with one another at their ends in a tube connecting device. A first tube end has a frame that is open on one side, this frame having a circumferential groove. A second tube end has a circumferential flange that is received in the circumferential groove. This open side of the frame is covered by a sealing strip fastened thereto, this strip clampingly spanning adjacent portions of the frame and flange.

Abstract: In a gas turbine propulsion unit with means for branching off compressor air for purposes of cooling hot parts of the turbine, the cooling air is conducted to the hot parts to be cooled along a detour by way of structural parts of high heat capacity and large surface area. It is achieved therewith that with a jump-like change of the cooling air temperature as, for example, during an acceleration operation, the cooling air gives off a portion of its heat content along the detour to the structural parts so that the thermal time behavior of the cooling air is slowed down.

Abstract: Sealing apparatus between inner and outer coaxial rotating shafts in which two sealing rings sealingly contact each other along confronting circumferential surfaces. In a position of rest, the rings surround the inner shaft with a predetermined circumferential sealing clearance of rotational symmetry. The sealing rings are supported in axially resilient manner between radial walls of a housing secured to the outer shaft which walls partly span the distance between the shafts. The sealing rings are pivotally connected to the housing for movement about pivot axes which are preferably 180.degree. apart from each other and, under the action of centrifugal force during rotation of the outer shaft, the rings pivot laterally towards surfaces of the housing to take up predetermined outer circumferential clearances of rotational symmetry between the outer periphery of the rings and the housing.

Abstract: A flow machine, especially a gas turbine equipped with means for separating an oil/air mixture and for returning centrifuged oil droplets to a circulation having oil consuming devices such as bearing places and with a vent line leading from the center toward the outside; the separating means includes a porous air-permeable element built into the hollow main shaft between two oil-impermeable walls whereby radially outer feed openings for the oil/air mixture are arranged in the upstream wall which correspond to openings in the main shaft while an air discharge opening is arranged in the downstream wall in its center which is in communication with the vent line.

Abstract: A device is provided for ultrasonic testing, particularly for monitoring the measuring precision and the calibrating of high resolution ultrasonic testing apparatus or ultrasonic testing heads. The device includes a powder-metallurgically produced test piece element. The test piece element includes insert elements immovably fixed to an interior surface of a capsule. Powder is provided in the capsule which is poured to surround the immovably fixed insert elements. The powder is subjected to changed temperature and pressure thereby forming the test piece. A process for producing the apparatus is also provided.

Abstract: A test piece for use in ultrasonic testing of materials or of powdered metallurgically manufactured workpieces to witness minute flaws, in which reference flaws are incorporated in at least one surface of the test piece or in the joint zone between test piece sections.

Abstract: Method and apparatus for optical measurement of fluid flow in which particles are injected into the fluid flow to permit accurate velocity measurements to be made thereof between two laser beams through measuring windows and to obtain a velocity profile. One beam is fixed and provides indication of start event, and the other beam is moved in discrete angular steps around the first beam in oscillatory fashion to provide indication of stop events. The sum of the particles passing the start beam and the sum of the particles subsequently passing the stop beam are correlated by electronic evaluation circuitry.

Abstract: A method and apparatus for measuring pressures in a gas turbine engine comprising a stator, a hollow rotatable shaft carrying a rotor and a first sensor having a plurality of inputs for pressure measured at respective test points on the rotor.

Abstract: A method for producing a collector vessel or manifold of a heat exchanger wherein the collector vessel is tubular and composed of a plurality of superimposed annular rings which are formed with recesses for receiving heat exchanger tubes of a matrix. The method comprises producing the annular rings from strips of predetermined profiled cross section by cutting the strips to predetermined length and rolling or coiling the strips and closing the rings by welding together their open ends. Thereafter a local displacement of material is achieved by rolling each of the closed rings and, in a subsequent rolling operation, in the plane of the ring, the material is deformed to produce recesses for the matrix tubes.

Abstract: A method including embedding a porous silicon ceramic compact, or workpiece, in a powder which is not sinterable at the process temperature, and subjecting the powder and embedded compact to heat and pressure in a hot isostatic press. The powder transmits the pressure to the compact. The powder may be the same material as the compact, except without a sintering agent, or the powder may be graphite powder. The grain size of the powder is between 2 .mu.m and 50 .mu.m. The powder and embedded compact are placed in a container prior to hot pressing; the container may be made of thin sheet metal or of quartz glass.

Abstract: The rotor of an axial-flow compressor with means for sealing the rotor blade tips relative to a casing wall provided with a coating is to be capable of abrasion but at the same time also low in wear. The present invention resolves these contradicting requirements for the coating on the casing in that individual blades, arranged between normally contoured, unshrouded rotor blades, are widened at their tips and reinforced with a radially outer layer, the material of which is matched to that of the coating. This will enable the coating to be subjected to less wear and to offer more resistance to erosion than heretobefore.

Abstract: A ceramic preform is coated with a layer of amorphous carbon and is then hot-isostatically compressed to form the desired ceramic part. The layer of carbon can then be removed.