Showing papers on "Nozzle published in 1999"

Droplet deposition apparatus

Abstract: Droplet deposition apparatus comprising an array of fluid chambers defined by a pair of opposing chamber walls, and in fluid communication with a nozzle for droplet ejection therefrom; a cover member is joined to the edges of the chamber walls and thus seals one side of the chambers. The cover member has a ratio of cover thickness to chamber wall separation less than or equal to 1:1.

Flow field and noise characteristics of a supersonic impinging jet

Abstract: This paper describes the results of a study examining the flow and acoustic characteristics of an axisymmetric supersonic jet issuing from a Mach 1.5 converging-diverging (C-D) nozzle and impinging on a ground plane. A large diameter circular plate was attached at the nozzle exit to measure the forces generated on the plate due to jet impingement. The experimental results described in this paper include lift loss, Particle Image Velocimetry (PIV) and acoustic measurements. Suckdown forces as high as 60% of the primary jet thrust were measured when the ground plane was very close to the jet exit. The PIV measurements were used to explain the increase in suckdown forces due to high entrainment velocities. The self-sustained oscillatory frequencies of the impinging jet were well-predicted using a feedback loop that utilizes the measured convection velocities of the large scale coherent vortical structures in the jet shear layer. Near field acoustic measurements indicate that the presence of the ground plane increases the OASPL by approximately 8 dB relative to a corresponding free jet. For moderately under expanded jets, the influence of the shock cells on the important flow features was found to be negligible except for close proximity of the ground plane.

Kinetic spray coatings

Abstract: Coatings have been produced by entraining metal powders in an air flow which is accelerated by a de Laval type of nozzle. The particles are not melted or thermally softened prior to impingement onto the substrate. The coating process depends primarily on the kinetic energy of the incident powders. The coatings have low oxide content and low thermal stress, and can exhibit relatively low porosity and high adhesion. The mechanism by which the coatings are formed is not well understood, and it is the goal of this work to provide some insights into this mechanism. We have produced a new high-velocity spray apparatus which allows the spray parameters to be controlled and monitored for the first time. This, together with our simulations of air and particle velocities and temperatures, has provided new information on the coating process. Al, Cu, and Fe powders were sprayed onto Al, brass, Cu, and steel substrates. A threshold behavior was observed for coating deposition as a function of nozzle inlet air temperature, with a roughly linear behavior above the threshold. Results are obtained as a function of nozzle inlet air pressure and temperature, powder feed rate, and nozzle–substrate stand-off distance. The effect of the choice of substrate metal was relatively weak in our experiments. Results seem consistent with necessary inelastic processes such as plastic deformation and/or partial melting of the powder particles upon collision with the substrate. More research is needed to define the relative importance of these phenomena or of other possible mechanisms.

Methods and apparatus for in situ formation of hydrogels

Abstract: Methods, and apparatus of forming in situ tissue adherent barriers are provided using a sprayer (90) capable of applying two or more viscous cross linking solutions to tissue The sprayer (90) comprises separate spray nozzles (98, 100) for each of two or more cross linking solutions, wherein each nozzle (98, 100) is in communication with a gas pressurized chamber (48) also may include valves (52) that prevent back flow through the supply lines (99, 101) carrying the cross linking solutions, and a venting system (106, 108) for venting excess pressure for laparoscopic applications In the presence of gas flow, the cross linking solutions are atomized, and mixed to form a spray Multi-component hydrogel systems suitable for use with the inventive methods, and apparatus are also described

Inkjet printhead having a self aligned nozzle

Abstract: An inkjet printing arrangement having a series of nozzles for the ejection of ink wherein the nozzle rims are formed as a result of the deposition of a rim material layer and a subsequent planar etching of the material layer so as to form the nozzle rim. The planar etching can comprise chemical-mechanical planarization of the rim material layer and any associated sacrificial layers.

Flow Separation and Side-Loads in Rocket Nozzles

Abstract: Flow separation in nozzles of rocket engines is undesired because it can lead to dangerous lateral forces, which might damage the nozzle The origin of side-loads is not fully clear, although different possible origins were identified in the past Meanwhile, it seems to be clear that in thrust-optimized or parabolic nozzles, a major side-load is due to the transition of separation pattern from free shock separation to restricted shock separation and vice versa After a literature review, the reasons for the transition between the separation patterns are discussed, and the cap shock pattern, which is identified to be the cause of this transition, is closely analyzed It turns out that this pattern can be interpreted as an inverse Mach reflection of the internal shock at the centerline The separation and side-load behavior of thrust-optimized and parabolic nozzles is described in detail In order to be able to predict the pressure ratio pc/pa at which the transition of separation patterns occurs, a model is developed which uses TDK-data as an input With the oblique shock relations and a momentum balance, both the ratio of chamber to ambient pressure and the value of the lateral force can be predicted with fair accuracy

Method and apparatus for lateral well drilling utilizing a rotating nozzle

Abstract: Method and apparatus for drilling into earth strata surrounding a well casing utilizing a rotating fluid discharge nozzle and reduction of static head pressure in the well casing in conjunction with the drilling operation.

Upright water extraction cleaning machine

Abstract: A portable surface cleaning apparatus has a base for movement along a surface to be cleaned and an upright handle pivotally attached to a rearward portion of the base. A fluid dispensing nozzle for applying fluid to the surface and a suction nozzle for picking up fluid and debris from the surface are associated with the base. A clean water holding tank and a detergent holding tank are removably mounted to the handle while a recovery tank is removably mounted to the base. A mixing valve is fluidly connected between the holding tanks and the spray nozzle for changing the mixing ratio of the detergent with respect to the water. The fluid recovery tank includes an integrally molded conduit that extends from the suction nozzle and a mounting for an accessory hose that interrupts the fluid path from the suction nozzle in the conduit and redirects fluid flow through the hose. A pump is fluidly connected between the mixing valve and the dispensing nozzle and includes a pump priming valve that operates on negative air pressure to clear air from the fluid lines during pump operation. A free floating brush is pivotally attached to the base for automatically adjusting to different surface conditions during cleaning operations.

Gas turbine fuel injector

Abstract: A fuel injector (22) for a combustor and a gas turbine engine, comprises a nozzle tip assembly protruding through the combustor wall (28) into the chamber, the nozzle tip (26) including a first air passage (60) forming an annular array, a second air passage made up of an annular array of individual air passages (62) spaced radially from the first air passage (60), both communicating the pressurized air from outside the combustor wall (28) into the combustor. Fuel is injected through an annular fuel nozzle (54) between the first air passage (60) and the second air passages (62). Third air passages (64) are arranged in annular array in the injector tip (26) spaced radially outwardly from the second air passages (62) whereby the third passages (64) are arranged to shape the mixture of atomized fuel and air and to add supplemental air to the mixture.

Simulation of Industrial Processes for Control Engineers

Abstract: Introduction Fundamental Concepts of Dynamic Simulation Thermodynamics and the conservation equations Steady state incompressible flow Flow through ideal nozzles Control valve flow Steady-state compressible flow Control valve liquid flow Liquid flow through the installed control valve Gas flow through the installed control valve Accumulation of liquids and gases in process vessels Two-phase systems - boiling, condensation and distillation Chemical reactions Turbine nozzles Steam and gas turbines Steam and gas turbines - simplified model Turbo pumps and compressors Flow networks Pipeline dynamics Distributed components: heat exchangers and tubular reactors Nuclear reactors Process controllers and control valve dynamics Linearization Model Validation Appendices: Comparative size of energy terms Explicit calculation of compressible flow using approximating functions Equations for control valve flow in SI units Comparison of Fisher Universal Gas Sizing Equation, FUGSE, with the nozzle-based model for control valve gas flow Measurement of the internal energy of reaction and the enthalpy of reaction using calorimeters Approximations used in modelling turbine reaction stages in off-design conditions Fuel pin average temperature and effective heat transfer coefficient Conditions for emergence from saturation for P + I controllers with integral desaturation

Transient Turbulent Gaseous Fuel Jets for Diesel Engines

Abstract: Existing data on transient turbulent jet injection in to large chambers demonstrates self-similar behavior under a wide range of conditions including compressibility, thermal and species diffusion, and nozzle under expansion. The Jet penetration distance well downstream of the virtual origin is proportional to the square root of the time and the fourth root of the ratio of nozzle exit momentum flow rate to chamber density. The constant of proportionality has been evaluated by invoking the concept of Turner that the flow can be modeled as a steady jet headed by a spherical vortex. Using incompressible transient jet observations to determine the asymptotically constant ratio of maximum jet width to penetration distance, and the steady jet entrainment results of Ricou and Spalding, it is shown that the penetration constant is 3 ± 0.1. This value is shown to hold for compressible flows also, with substantial thermal and species diffusion, and even with transient jets from highly under-expanded in which, as in diesel engine chambers with gaseous fuel injection, the jet is directed at a small angle to one wall of the chamber. In these tests, with under expanded nozzles. Observations of transient jet injection have been made in a chamber in which, as in diesel engine chambers with gaseous fuel injection, the jet is directed at a small angle to one wall of the chamber. In these tests, with under-expanded nozzles it was found that at high nozzle pressure ratios, depending on the jet injection angle, the jet penetration can be consistent with a penetration constant of 3. At low pressure ratios the presence of the wall noticeably retards the penetration of the jet.

Tabbed nozzle for jet noise suppression

Abstract: The present invention relates to a gas turbine engine exhaust nozzle for suppressing jet noise. The nozzle has an arrangement of tabs that extend in radially inward and outward directions. The tabs cause the formation of vortices which pull into mixing engagement the exhaust gas streams from the core and fan ducts and the ambient air. In addition, various construction details are developed for the tab arrangement including tabs that are directed radially inwardly and outwardly, and tabs that are continuous with the nozzle duct therebetween.

Variable flow and pressure ventilation system

Abstract: A ventilation system supplies a gas mixture that is humidified and heated through a proportional valve (22) which is a fail closed and normally closed servo control valve positioned proximate a patient. The proportional valve (22) is operated by a controller that regulates the pressure and the mode (e.g., high frequency, normal respiration, combinations) gas is delivered to the patient through a nozzle (30) connected to the endotracheal tube (42). The nozzle (30) has an exhaust connected to it and a pressure sensor (44) through a pressure sensing port. The exhaust is a capped corrugated tube that is heated and perforated to allow air to escape, to muffle gas and respiration noises, and to trap moisture.

Laser beam machining head

Abstract: A laser beam machining head includes a dividing optical system for dividing laser light into two separate laser beams, and providing spacing therebetween; a condensing optical system for condensing the separate laser beams into condensed laser light, and projecting it onto a cutting site of an object to be cut; and an inner assist gas nozzle placed between the separate laser beams, a width of an opening of a tip portion of the inner assist gas nozzle being nearly equal to a cutting width. Or the tip opening of the inner assist gas nozzle is slender; or its tip side is inclined, and the angle of inclination is variable; or the relative positions of the inner assist gas nozzle and a workpiece, or the relative positions of the focal position of the condensing optical system and the workpiece are variable independently; or an outer assist gas nozzle surrounding the separate laser beams is provided.

Air atomizing nozzle assembly with improved air cap

Abstract: An air assisted spray nozzle assembly having an air cap effective for generating wide, flat spray patterns with improved liquid particle breakdown, utilizing relatively low air flow rates and pressures. The air cap includes a pair of longitudinally extending air passageways on opposite sides of a central liquid flow stream discharge orifice. The air flow passages each have a discharge orifice defined by a respective transverse deflector flange and a closely spaced inwardly tapered deflector surface which cooperate to deflect and guide pressurized air streams inwardly toward the discharging liquid flow stream for atomizing the liquid and for directing it into a well defined spray pattern.

Integrated power module

Abstract: An integrated power module for generating thermal and electrical power is provided within a housing (110) which includes inlets for fuel (156) and for air (112), a reformer chamber (116), a fuel cell stack (118), and a combustion chamber (120). Oxygen-containing gas, such as air, is introduced into the module along path (114) in one direction in heat-exchange relationship with reaction products produced in the reaction chamber traveling in an adjacent path, preferably in an opposite direction, to preheat the incoming oxygen-containing gas. A nozzle (169) having an injector for the fuel and for the oxygen-containing gas delivers these gases to the interior of the reformer chamber, where the ignition is supplied by a suitable device. The reaction products from the reformer chamber are fed to a fuel cell which will consume certain of the reaction products, such as hydrogen gas, with oxygen provided from the reaction chamber acting as an oxidizing gas. Exchange between a cathode and an anode will effect the generation of current, as well as the production of water, which normally will be absorbed as steam and passed from the fuel cell. The current generated by the fuel cell can be delivered externally to a user, while hydrogen may be combusted downstream in the combustion chamber to provide an added thermal energy source for heating. In alternative embodiments of the power module, the fuel cell is used as a shift reactor and hydrogen purification device. The primary product of this module is purified hydrogen gas in addition to heat.

Active control of combustion instability in a liquid-fueled low-NOx combustor

Abstract: A practical active control system for t nitigation of combustion instability has been designed and demonstrated in a lean, premixed, single-nozzle combustor at realistic engine operating conditions A full-scale engine fuel nozzle was modified to incorporate a simple fuel flow actuator Results indicate that the system was capable of reducing pressure fluctuations by 82 percent (15 dB or 56×) while maintaining or reducing NO x and CO emissions levels

Ink jet recording head and ink jet recording apparatus comprising the same

Abstract: An ink jet recording head comprises a nozzle forming member provided with a plurality of nozzle orifices for jetting ink, a channel forming substrate provided with a plurality of pressure generating chambers communicated with the associated nozzle orifices, one face of which is bonded to the nozzle forming member, a plurality of piezoelectric elements provided on an face of the channel forming substrate which is opposed to the face bonded to the nozzle forming substrate for causing pressure change to occur in the associated pressure generating chambers, and a reservoir forming member bonded to the face of the channel forming substrate on which the piezoelectric elements are provided, the reservoir forming member having a reservoir section forming at least a part of a reservoir communicated with the pressure generating chambers for supplying ink thereto and a piezoelectric element holding section for defining a space in an area facing the piezoelectric elements such an extent that motion of the respective piezoelectric elements is exhibited while sealing the space hermetically.

Large eddy simulation of a Mach 0.9 turbulent jet

Abstract: Large eddy simulations of an isothermal Mach 0.9 jet (Re = 10) issued from a convergent-straight nozzle are performed using the compressible flow solver CharLES. The flow configuration and operating conditions match the companion experiment conducted at the PPRIME Institute, Poitiers. To replicate the effects of the boundary layer trip present in the experiment and to ensure a turbulent jet, localized adaptive mesh refinement, synthetic turbulence, and wall modeling are used inside the nozzle. This leads to fully turbulent nozzle-exit boundary layers and results in significant improvements for the flow field and sound predictions, compared to those obtained from the typical approach based on laminar flow assumption in the nozzle. The far-field noise spectra now match the experimental measurements to within 0.5 dB for relevant angles and frequencies. As a next step toward better understanding of turbulent jet noise, the large database collected during the simulation is currently being used for reduced order modeling and wavepacket analysis (Jordan et al. 2014).

Flow cytometer nozzle and flow cytometer sample handling methods

Abstract: An improved nozzle system for a flow cytometer and accompanying methods have been invented for a high efficiency orientation and sorting process of a flat sample and dedicates items such as equine or bovine sperm cells. This improved nozzle system comprises a nozzle with a novel interior surface geometry that can both gently accelerate the cells and can include an elliptical-like, single torsional interior surface element within the nozzle, i.e., a single torsional orientation nozzle. The elliptical-like, single torsional interior surface element may have a laminar flow surface and may produce the simplest flow path for applying minimal forces which act in either an accelerative nature or orienting hydrodynamic forces, namely, the single torsional orientation forces, to orient a flat sample such as animal sperm cells into a proper direction for an analyzing and efficiently sorting process in clinical use, for research and for the animal insemination industry.

Feedback-free fluidic oscillator and method

Abstract: A fluidic oscillator includes a member having an oscillation inducting chamber (IC), at least one source of fluid (SF) under pressure, at least a pair of power nozzles (FH1, FH2) connected to the at least one source of fluid under pressure for projecting at least a pair of fluid jets into the oscillation chamber, and at least one outlet from the oscillation chamber for issuing a pulsating jet of fluid to a point of utilization or ambient. A common fluid manifold connected to said at least a pair of power nozzles. The shape of the power nozzle manifold forms one of the walls of the interaction or oscillation chamber. In some of the fluidic circuits, the length can be matched to fit existing housings. The power nozzle can have offsets which produce yaw angles in a liquid spray fan angle to the left or right depending on the direction desired. In some embodiments, the exit throat is off axis (off the central axis of the symmetry) by a small fraction to the left or right to move the leftward or rightward yaw angles in the spray. The outlet throat (BX) may be offset along the longitudinal axis by a small amount to produce a yaw angle of predetermined degree to the left or right depending on what is desired. Thus, one can construct circuits for yaw using a combination of the techniques described above which suits most applications.

Characterization of the spray droplet spectra and patterns of four venturi-type drift reduction nozzles

Abstract: Laboratory studies were conducted using a Malvern laser droplet/particle size analyzer to determine the droplet spectra of several venturi-type drift reduction nozzles compared to a standard single, elliptical-orifice flat fan nozzle. Spray solutions of glufosinate, glyphosate, and paraquat were applied through all combinations of five nozzle types (four drift reduction), three tip sizes, and four application pressures. Nozzles were also evaluated for pattern uniformity using water plus surfactant at one pressure. When averaged over herbicide, tip size, and pressure the venturi nozzles collectively produced larger volume median diameter (VMD) droplets than the standard nozzle. The percentage of spray volume in droplets glyphosate (460 ,um) > glufosinate (400 (Lm), as measured by VMD. The venturi nozzles were more variable in their spray volume distribution than the standard nozzle. Utilization of venturi-type nozzles may minimize the drift potential of the herbicides evaluated but could also lead to uneven herbicide application and subsequent erratic weed control. Nomenclature: Glufosinate, 2-amino-4-(hydroxymethylphosphinyl)butanoic acid; glyphosate, iso- propylamine salt of N-(phosphonomethyl)glycine; paraquat, 1,1 '-dimethyl-4,4'-bipyridinium ion. Additional index words: Glufosinate, glyphosate, paraquat, Malvern, venturi nozzle. Abbreviations: Al, Spraying Systems Al Teejet; CV, coefficient of variation; HSD, Tukey's honest significant difference; LM, Lurmark Ultra Lo-Drift; MMD, mass median diameter; NIS, nonionic surfactant; POST, postemergence; PRE, preemergence; RU, Delavan Raindrop Ultra; TD, Greenleaf

A thermal inkjet printhead with a monolithically fabricated nozzle plate and self-aligned ink feed hole

Abstract: A monolithic thermal inkjet printhead has been developed and demonstrated to operate successfully by combining monolithic growing of a nozzle plate on the silicon substrate and electrochemical etching of silicon for an ink feed hole. For the monolithic fabrication, a multiexposure and single development (MESD) technique and Ni electroplating are used to form cavities, orifices, and the nozzle plate. Electrochemical etching, as a back-end process, is applied to form an ink feed hole through the substrate, which is accurately aligned with the frontside pattern without any backside mask. The etch rate is nearly proportional to the current density up to 50 /spl mu/m/min. Experiments with a 50-/spl mu/m-diameter nozzle show ink ejection up to the operating frequency of 11 kHz with an average ink dot diameter of about 110 /spl mu/m for 0.3-A, 5-/spl mu/s current pulses.

A dual fuel nozzle

Abstract: A dual fuel nozzle is provided with two different size injection holes. The first injection holes have larger diameters and are used only for injecting gaseous fuel into a combustion chamber. On the other hand, the second injection nozzles have smaller diameters and are used for injecting either gaseous fuel or liquid fuel as required. When gaseous fuel is used, if the fuel injection amount is large or medium, both of the first and the second injection holes or first injection holes only are used for injecting gaseous fuel depending upon the required fuel injection amount. When the fuel injection amount is low, only the second injection hole is used for injecting gaseous fuel. Therefore, the pressure drop across the fuel nozzle can be kept at sufficiently high level even when the fuel injection amount is low, and thereby combustion vibration is suppressed. Further, when liquid fuel is used, a premixed fuel and steam mixture is injected from the second injection holes. This also keep the pressure drop across the fuel nozzle at high level in order to suppress combustion vibration when the fuel injection amount is low.