Showing papers on "Nozzle published in 1976"

Noise suppressing exhaust mixer assembly for ducted-fan, turbojet engine

Abstract: To suppress jet noise emanating from a ducted-fan turbojet engine, an improved exhaust mixer assembly is disclosed that is mounted between the engine and the exhaust nozzle and that mixes the flow of high-velocity primary gases (turbine exhaust) with the lower-velocity air from the fan duct in a manner that achieves a significant reduction in the proportion of noise-causing high velocity gases while maintaining approximately the same thrust from the nozzle as other mixer-equipped engines. The mixer assembly includes an annular sleeve, a bulb-shaped plug disposed concentrically within the sleeve, and an annular corregugated mixer duct coaxially positioned between the plug and sleeve wherein these components are arranged so as to receive the primary and fan flows and separately redirect these flows within the assembly so that the flow of primary gases is rearwardly divergent while the flow of fan air is rearwardly convergent. As the primary and fan flows pass through a mixing plane at the aft terminus of the mixer duct, they intersect in a crossing pattern resulting from their divergent-convergent flow paths which yields faster and more complete mixing of the flows before they are discharged from the nozzle. The shaping and dimensioning of the sleeve, plug, and mixer duct are such that optimum mixing, and thus maximum suppression of noise, are achieved without introducing any excessive pressure losses in the mixer assembly and nozzle that otherwise would significantly diminish thrust.

Turbojet engine nozzle for attenuating core and turbine noise

Abstract: Core noise, a low frequency noise component believed to be partly caused by the combustion processes within the engine, and turbine noise, a higher frequency noise component caused by the interaction of high velocity gases with the engine's turbine, are attenuated by noise absorbing structures that are disposed within the engine's nozzle and that in part define the physical geometry of the nozzle duct. The nozzle is formed of an outer sleeve and an inner generally bulb-shaped plug which are coaxially arranged to define an annular nozzle duct that channels the flow of gases rearwardly from the outlet of the engine's turbine. The plug has a hollow interior that is partitioned into a plurality of cavities that communicate with the nozzle duct via perforations provided in an outer wall of the plug. The size, shape and positioning of the interior cavities and outer plug wall perforations are selected so as to absorb noise energy existing in the exhaust gases, both at the relatively low frequencies characteristic of core noise and at the relatively higher frequencies characteristic of turbine noise.

The Occurrence of Stagnation Bubbles in Supersonic Jet Impingement Flows

Abstract: This paper reports an experimental investigation into the stagnation bubbles found in the shock layers of some supersonic jets impinging on perpendicular flat plates at small nozzle-to-plate distances. The experiments used twelve contoured nozzles within the Mach number range 1.42 to 2.83. Surface pressures were measured on the plate and free-jet pitot pressure distributions were obtained at the level of the centre of the plate shock. Schlieren pictures were taken of both impinging and free jets. It was found that the bubbles result from the interaction of the plate shock with very weak shock waves which are produced in the jet either by small imperfections in the nozzle wall or by slight inaccuracies in the design or production of the nozzle contour. The bubbles can be eliminated by suitable improvements to the nozzle. Other anomalous flows produced by shock interactions are described and explanations offered. It is shown that the bubbles sometimes encountered at close plate spacings with conical nozzles are also due to shock waves. However, for wide-angled nozzles, internal shocks can be an inherent part of the flow from the nozzle and the bubbles which they produce are thus an inherent part of the impingement flow. From physical arguments concerning the main factors involved in producing a bubble, a parameter is constructed whose values are shown to be a good criterion for whether a bubble occurs or not.

Gas turbine exhaust nozzle for controlled temperature flow across adjoining airfoils

Abstract: An exhaust nozzle for exhausting the effluent of a turbofan gas turbine engine across a portion of the upper surface of an aircraft wing wherein the exhaust nozzle is arranged to establish a temperature profile within the exhausted gases that prevents overheating the wing surface. The nozzle includes a contoured outer housing that longitudinally transists from a circular entrance opening, arranged for interconnection with the rear face of a gas turbine engine, to a semi-elliptical outlet opening located on the upper surface of the aircraft wing. A generally tubular mixer section, of the daisy type, is mounted within the outer housing and coaxially surrounds an engine tail plug. Exhaust gases flowing from the engine fan stage flow through an annular flow duct formed between the inner surface of the forward portion of the outer housing and the outer surface of the mixer section and the high temperature gases flowing from the engine turbine stages flow through an annular duct formed between the tail plug and the inner surface of the mixer section. As the turbine exhaust gases and the fan air flow past the mixer section exit plane, the two fluid streams mix with one another to increase engine thrust and decrease engine noise level. To establish a temperature profile in which the exhaust gases flowing along the aircraft wing do not overheat the wing structure, the outer housing is contoured to have a generally elliptical cross-sectional geometry at the exit plane of the mixer section and the mixer section lobes are of unequal radial dimension such that the mixer section has an asymmetric cross-sectional shape.

Injection molding nozzle seal

Abstract: This invention relates to a nozzle seal to be used in multi-cavity valve-gated injection molding. A heater cast with a lower nozzle portion is spaced from a cavity plate by an insulating air space and the valve pin reciprocates vertically in the heater cast bore into a gate in the cavity plate. A hollow generally cylindrical nozzle seal is provided across the air space between the lower tip of the nozzle portion and the cavity plate around the gate. The cylindrical seal provides additional heat transfer from the heater to the area of the gate to facilitate operation of the valve pin, particularly seating of the valve pin in the gate, during molding of certain plastic materials with high temperature characteristics. The nozzle seal is formed of a high yield strength titanium alloy and structured to avoid leakage or breakage in this critical area due to high injection pressure and both vertical and lateral relative movement between the nozzle and the cavity plate due to thermal expansion and contraction. In a second embodiment, a lower portion of the seal is tapered to improve sealing at high pressures and heat transfer to the immediate gate area and to avoid a "dead spot" for the accumulation of molten plastic material adjacent the gate.

Vortex generators for internal mixing in a turbofan engine

Abstract: Method and apparatus for reducing jet noise in a turbofan engine by causing internal mixing of fan and primary air to reduce the maximum velocity of gases at the nozzle exit plane by creating a particular type of vortex flow at a distance of at least one nozzle diameter forward of the nozzle exit plane. In one preferred embodiment for a JT8D engine an array of eight roll-top vortex generators are provided on each side of the splitter wall between fan and primary flows, and a portion of the fan air may be introduced into the central portion or core of the hot primary air.

Windshield washer and deicer

Abstract: A windshield washing and deicing system comprising a reservoir for containing washer fluid having a sealed container supported therein. A pump is effective to transfer washer fluid from the reservoir to the container and from the container to a plurality of nozzles located adjacent a vehicle window. A conduit is located in the reservoir for carrying heated engine coolant through the reservoir to heat the washer fluid therein. An electrical resistance wire is provided for further heating the washer fluid in the container whenever the temperature of the fluid in the container is below a predetermined minimum to quickly deice the vehicle window.

Fluid-cooled element

Abstract: A fluid-cooled element for partially defining hot gas flow passage extending upstream and downstream of a minimum area throat. A serpentine conduit of fluid communication with a coolant source routes cooling fluid within the downstream portion of the element wall bounding the hot gas passage to an internal pocket upstream of the throat. The coolant is thereafter exhausted upstream of the throat as a film over the wall. The upstream wall portion is cooled by the known impingement and film-cooling technique resulting in an element wherein all of the coolant enters the hot gas passage in a low Mach number region upstream of the throat, thereby minimizing momentum losses due to mixing. In the preferred embodiment, the passage throat is defined by a plurality of turbine nozzle vanes, the fluid-cooled element comprising a nozzle band thereof. Flanges support the nozzle within a gas turbine engine and are located upstream of the nozzle throat so as to provide a barrier which minimizes coolant leakage downstream of the throat.

The Generation and Radiation of Supersonic Jet Noise. Volume 3. Turbulent Mixing Noise Data

Abstract: : The characteristics, both spectral and directivity, of the sound field of supersonic shock-free jets are studied by measuring the turbulent mixing noise in the far field from four two-inch diameter nozzles, namely a convergent nozzle for pressure ratios up to critical and three convergent- divergent nozzles having nominal design Mach numbers of 1.4, 1.7, and 2.0, respectively. The measurements were conducted in a free-field environment. The results from 75 jet exit conditions are presented in a systematic manner in the form of tabulated one-third octave spectra. The test program was carefully planned in order to obtain results (i) at constant jet efflux temperature with varying jet velocity, and conversely (ii) at constant exit velocity while varying jet efflux temperature. The effects of jet velocity and exhaust temperature on turbulent mixing noise can therefore be assessed independently.

Apparatus for treating rock surrounding a wellbore

Abstract: An apparatus for treating rock surrounding a wellbore comprises a hollow elongated housing having nozzles radially mounted therein, which are projectable externally thereof. Each nozzle has a through passage communicating with the internal space of the housing to pass the flow of a fluid with an abrasive filler therethrough. The external end faces of the nozzles are shaped so as to press against the wall of the casing. Each through passage of the nozzle has a larger-diameter portion at the end thereof, facing the casing wall. The body of each nozzle has auxiliary passages, each such passage having one end thereof communicating with the larger-diameter portion of the through passage and the other end thereof communicating with the space externally of the nozzle, the auxiliary passages affording the flow of the fluid with the abrasive filler from the space defined by the said larger-diameter portion of the through passage and the adjacent casing wall, as the nozzle is closely pressed against the casing.

The physical behavior of a gas jet injected horizontally into liquid metal

Abstract: The gas fraction and bubble frequency distributions in a submerged air jet, injected horizontally into mercury, have been measured under isothermal, nonreactive conditions for nozzle diameters of 0.325 and 0.476 cm and jet Froude numbers ranging from 20.5 to 288. The measurements reveal that the jets expand extremely rapidly upon discharge from the nozzle with an initial expansion angle of 150 to 155 deg. This value, which is over seven times greater than is found with air jets in water, indicates that the physical properties of the liquid exert considerable influence on the jet behavior. In conjunction with the rapid expansion, the air jets in mercury were also found to penetrate extensively behind the nozzle, and in many respects resembled a vertically injected jet. The extent of backward penetration of the jets was constant for all blowing conditions studied while the forward penetration increased with both increasing jet Froude number and nozzle diameter. The measured jet penetration in both the forward and backward directions were considerably larger than expected from model predictions. The core of the jets consists of a high concentration of gas bubbles. Both the gas volume fraction and bubble frequency in the core increase with increasing jet Froude number and nozzle diameter. The gas concentration and bubble frequency decrease with increasing distance along the jet trajectory due presumably to entrainment of liquid metal and bubble coalescence. On the basis of these findings, it is likely that process jets, such as are injected into copper converters, also expand rapidly and penetrate only a short distance into the bath. Thus rather than reacting in the middle of the bath, the jets may be impinging on the backwall refractory and contributing to the erosion observed there.

Spray Drift and Recovery As Affected by Spray Thickener, Nozzle Type, and Nozzle Pressure

Abstract: DRIFT continues to be a major problem in applying agricultural pesticides. Recent developments aimed at reducing the formation of small spray droplets include atomizers such as foaming nozzles, uniform droplet generators, Raindrop nozzles, low- and reduced-pressure nozzles, and the use of thickening agents to increase the viscosity of the dispensed liquid. Because of the variability in climatic conditions, few data are available to show the actual amount of drift reduction obtained from these atomizers and formulation modifiers. Field tests are being used at the University of Illinois to study the drift from ground sprayers. The purposes of this research are to measure the effectiveness of new spray thickeners, spray atomizers, and application techniques in reducing drift; and to obtain data useful for the refinement of a drift-prediction model.

An analytical description of the jet finishing process for hot-dip metallic coatings on strip

Abstract: An analytical study of the jet finishing of hot-dip metallic coated strip which relates the final solidified coating thickness to strip speed, jet nozzle operating parameters, and coating metal and finishing fluid properties is described. The results of laboratory and mill tests are compared with the predictions of the analytical model and engineering considerations for jet nozzle operation to reduce coating weight at increased line speed are discussed.

Turbine wheel with catenary blades

Abstract: A turbine wheel on a horizontal axis is coaxially mounted within a primary nozzle, for support in a fluid current below a platform carrying electrical power generation equipment. The turbine wheel and primary nozzle are submerged and oriented to enable flow of a portion of fluid current through the nozzle and past the turbine wheel. The turbine wheel comprises a shroud-ring rim, a set of blades extending inwardly toward the axis, the blades being mounted at their outer ends on the inside of the rim, and at their inner ends on the outside of an axial hub. Each blade has its longitudinal tensile elements shaped in the form of part of a relaxed catenary, extending from rim to hub, with sufficient bow in the direction of force of fluid current on the blade to provide a practical wheel of reasonable cost. Struts and strut vanes supporting hub elements within the nozzle may also be of relaxed catenary configuration.

Fluid sampling apparatus

Abstract: Improved apparatus for bringing a fluid in a process stream in contact with a sensor is disclosed. The present invention uses the kinetic energy of the process fluid to convey some of the fluid to and from the sensor, as opposed to the prior art practice of inserting the sensor itself into the process fluid stream. A nozzle is placed into the process fluid stream facing into the direction of flow. A small portion of the flowing process fluid is trapped by the nozzle and some of its kinetic energy is converted to pressure. This pressure causes a flow from the nozzle into a conduit through an open valve to the sensor. The fluid continues past the sensor and returns to the process fluid stream through the same valve. In one embodiment, the path for incoming fluid and exiting fluid are separate paths. In a second embodiment, the incoming fluid and exiting fluid exist coaxially.

Trigger type spraying device

Abstract: A fluid is sprayed from a nozzle aperture of a trigger type spraying device under pump pressure generated by the pumping action of an injection pipe member lifted and lowered vertically by an operating mechanism Said injection pipe member includes a vertical pipe portion, corresponding to a piston, and an oblique pipe portion inclined to said vertical pipe portion At the tip of said oblique pipe portion, there is provided a discharge valve having an elastically deformable ring member in such a manner that pulling of the trigger portion of a crank lever forces the lower half of said vertical pipe portion, corresponding to the piston, into the cylinder, thereby producing a pumping action The fluid pressurized in the pump chamber exerts pressure, through means of a fluid passage in the injection pipe member, onto the ring member of the discharge valve in a direction whereby the ring member is flexed so as to open the valve, thereby causing the fluid to be sprayed conically from the nozzle aperture

Airless spray nozzle and method of making it

Abstract: An airless spray coating nozzle is made by cutting interpenetrating grooves into opposite sides of a nozzle tip blank. The groove on the pressurized or entrance side of the tip has a bottom portion which is wedge-shaped in cross section. The groove on the unpressurized or exit side of the tip has a bottom portion which is trapezoidal in cross section. Both grooves are cut into the nozzle tip with a grinding wheel after the tip has been hardened.

Burners for flame jet drill

Abstract: A burner in the form of a flame jet drill bit engine for liquid fuels is disclosed. The burner has particular utility in a flame jet drill and comprises an axially elongated body with a combustion chamber disposed therein. At least one flame jet nozzle is disposed through the body adjacent the bottom so as to communicate with the reaction chamber. At least one set of water or other liquid jet nozzles is also disposed on the bottom of the body which produce a pulsating water jet at extremely high velocities. The flame jet nozzle and the water jet nozzles are arranged and configured on the bottom of the body so as to be substantially parallel to the axis of the body. By the use of the combination of flame jets and water jets, a cutting means is produced which can cut through a wide range of amorphous and sedimentary rocks.

Numerical Prediction of the Flow Field and Impingement Heat Transfer Caused by a Laminar Slot Jet

Abstract: The effects of uniform suction and nozzle exit velocity profile on the flow and heat-transfer characteristics of a semiconfined laminar impinging slot jet were investigated numerically. The full Navier-Stokes and energy equations were solved using a hybrid or upwind finite-difference representation of the equations cast into their vorticity-stream-function form. The importance of the nozzle exit profile is shown by comparison of the computed heat-transfer distribution with the available experimental data in the laminar range. Application of suction at the impingement surface is shown to enhance the local heat-transfer rates by a constant amount. The nondimensional heat-transfer coefficient and skin friction at the plate are computed as functions of the nozzle Reynolds number, the suction rate, and the nozzle velocity profile. The effect of temperature-dependent physical properties is included in the analysis.

Apparatus and process for the removal of pollutant material from gas streams

Abstract: A process and apparatus is disclosed for the removal of pollutant material including solid or liquid particulate matter and gaseous pollutants from gas streams in which the gas is driven through a mixing tube by forming a jet of a compressible fluid such as steam or air or the whole or a part of the polluted gas itself. In some instances the jet acts as an ejector to induce flow of the polluted gas into the mixing tube but when all of the polluted gas is formed into a jet it is directed into the mixing tube without any ejector action. A mechanically atomized liquid is introduced into the outer region of the jet of compressible fluid emerging from the nozzle in which the jet is formed. The mechanically atomized liquid is further atomized by the shearing action of the jet to form high velocity droplets which are intimately and turbulently mixed with the pollutant-containing gas and retained in the mixing tube for a sufficient time so that the pollutants become entrained with the water droplets. The turbulent mixture is then directed into a diffuser having an increasing cross-sectional area and deflected as it enters the diffuser away from one portion of the interior surface of the diffuser and toward an opposite portion of the interior surface of the diffuser and also decelerated so as to cause a separation in the flow of the liquid and non-liquid constituents of the mixture. Apparatus is disclosed including a compressible fluid nozzle for forming the jet and a liquid injector, a mixing tube, a diffuser, and fluid and mechanical separating means whereby a separate flow of the particulate material including submicronic sized particulate entrained in liquid droplets is established in the diffuser for removal from the cleaned gas stream. If it is desired to remove reactive gaseous pollutants from a gas stream, appropriate chemical reagents may be added to the injected liquid or directly to the gas stream prior to treatment.

Non-equilibrium plasma glow jet

Abstract: A high power density continuous wave (c. w.) gas dynamic laser system is described which includes a non-equilibrium plasma jet for generating excited gaseous species having high vibrational temperature and low gas temperature. Gas flow through the plasma jet is reduced to highly turbulent subsonic flow by an expanding nozzle. Lasing in an optical cavity oriented transversely with respect to the flow of the gaseous plasma extracts vibrational energy from the excited gaseous species as the emerge from the expansion nozzle. The described system also includes, immediately upstream from the optical cavity, an injection system which introduces and uniformly mixes a lasing gaseous species into the highly turbulent subsonic gaseous plasma flow from the plasma jet. Gas sweeps are established in the arms of the optical cavity to cool and sweep high temperature unexcited gas species therefrom in order to reduce absorption in the optical cavity. The described laser system can be adapted for either open cycle or closed cycle operation depending upon the gaseous mediums utilized. A particular carbon dioxide - nitrogen gas dynamic laser system is described which has a gain coefficient of 32/m at 20 torr of carbon dioxide and 40 torr of nitrogen with an estimated power density of approximately 1000 W/cm 3 , a saturation parameter of approximately 2000 W/cm 2 and an estimated overall efficiency of approximately 24%.

Ultrasonic wave fuel injection and supply device

Abstract: An ultrasonic wave fuel injection and supply device includes an ultrasonic wave generating device and a fuel injection nozzle device. The ultrasonic wave generating device in turn includes an ultrasonic transformer, for transforming electrical oscillations into mechanical vibrations, connected to an ultrasonic oscillator, a mechanical vibration amplifier, for amplifying the amplitude of the mechanical vibrations, secured to the ultrasonic transformer, and a vibratory member, having a hollow cylindrically shaped body the peripheral wall of which is secured to the tip of the mechanical vibration amplifier with the axis of the vibratory member being disposed substantially perpendicular to the longitudinal axis of the mechanical vibration amplifier. The vibratory member has its opposite ends open and is disposed within an intake passage of an engine, the same therefore not hindering the flow of fluid through the intake passage. The fuel injection nozzle has its nozzle opening directed toward the peripheral wall of the vibratory member for injecting liquid fuel under pressure onto the peripheral wall. A fuel supply device introduces liquid fuel from a fuel reservoir to the injection nozzle, and a control device controls the amount of fuel being injected through the injection nozzle in response to the running conditions of the internal combustion engine. The ultrasonic wave fuel injection and supply device thus atomizes and scatters the liquid fuel injected onto the peripheral wall of the vibratory member as a result of the ultrasonic vibrations thereof, and the atomized and scattered liquid fuel is supplied to the combustion chamber of an engine, together with air from an air cleaner.

Apparatus and method for spray application of solvent-thinned coating compositions

Abstract: An apparatus and method for the spray application of solvent-thinned coating compositions whereby optimum coverage of a substrate with a liquid film is consistently achieved without incurring sagging, run-off or surface irregularities, such as orange peeling, in spite of wide fluctuations in the temperature and/or humidity of the surrounding atmospheric environment. In accordance with the invention, a shroud is provided which is disposed in encompassing relationship around the spray nozzle to which air is supplied at a controlled temperature and/or humidity which envelopes and becomes entrained in the spray forming a controlled localized atmosphere and achieving a controlled vaporization of solvent from the liquid droplets during the course of their travel from the nozzle to the surface of the substrate being coated.

Fuel injection apparatus

Abstract: A servo piston is driven to compress fuel in a pressure chamber which communicates with a needle valve which is spring biased to block communication between the pressure chamber and a fuel injection nozzle. When the fuel pressure exceeds a value equivalent to the preload of the spring, the pressurized fuel moves the needle valve off its seat so that fuel from the pressure chamber is injected into an engine through the injection nozzle. Further movement of the servo piston unblocks a port to allow fuel at supply pressure to act on the needle valve in the same direction as the spring to sharply seat the needle valve and cleanly terminate fuel injection. Further movement of the servo piston uncovers another port so that the pressure chamber is depressurized through connection with the supply and the needle valve is firmly held on its seat.

Nozzle selector valve

Abstract: A multi nozzle high pressure fluid sprayer which can be safely indexed to a selected nozzle while the sprayer is under high fluid pressure. The sprayer contains separate seals at the inlet of each nozzle to permit a safe and effective indexing to either of the nozzles while the fluid is under high pressure or to provide a total shutoff of the fluid. The sealing arrangement includes a channel to provide back pressure to the seal area around each of the nozzles to prevent the seals from being disgorged or damaged as the sprayer head is indexed from nozzle to nozzle while under high pressure.