Showing papers on "Nozzle published in 2002"

Method of and apparatus for tunable gas injection in a plasma processing system

Abstract: A method of and apparatus for providing tunable gas injection in a plasma processing system ( 10, 10′ ). The apparatus includes a gas injection manifold ( 50 ) having a pressurizable plenum ( 150 ) and an array of adjustable nozzle units ( 250 ), or an array of non-adjustable nozzles ( 502, 602 ), through which gas from the plenum can flow into the interior region ( 40 ) of a plasma reactor chamber ( 14 ) capable of containing a plasma ( 41 ). The adjustable nozzle units include a nozzle plug ( 160 ) arranged within a nozzle bore ( 166 ). A variety of different nozzle units are disclosed. The nozzle plugs are axially translatable to adjust the flow of gas therethrough. In one embodiment, the nozzle plugs are attached to a plug plate ( 154 ), which is displacable relative to an injection plate ( 124 ) via displacement actuators ( 170 ) connecting the two plates. The displacement actuators are controlled by a displacement actuator control unit ( 180 ), which is in electronic communication with a plasma processing system control unit ( 80 ). The gas flow into the chamber interior region is preferably controlled by monitoring the pressure in the plenum and in the chamber and adjusting the nozzle units accordingly. Where the nozzle units are not adjustable, a portion of the nozzles are sized to a first flow condition, and another portion of the nozzles are sized to a second flow condition.

The stretching of an electrified non-Newtonian jet: A model for electrospinning

Abstract: Electrospinning uses an external electrostatic field to accelerate and stretch a charged polymer jet, and may produce ultrafine “nanofibers.” Many polymers have been successfully electrospun in the laboratory. Recently Hohman et al. [Phys. Fluids, 13, 2201 (2001)] proposed an electrohydrodynamic model for electrospinning Newtonian jets. A problem arises, however, with the boundary condition at the nozzle. Unless the initial surface charge density is zero or very small, the jet bulges out upon exiting the nozzle in a “ballooning instability,” which never occurs in reality. In this paper, we will first describe a slightly different Newtonian model that avoids the instability. Well-behaved solutions are produced that are insensitive to the initial charge density, except inside a tiny “boundary layer” at the nozzle. Then a non-Newtonian viscosity function is introduced into the model and the effects of extension thinning and thickening are explored. Results show two distinct regimes of stretching. For a “mild...

Process and apparatus for organic vapor jet deposition

Abstract: A method of fabricating an organic film is provided. A non-reactive carrier gas is used to transport an organic vapor. The organic vapor is ejected through a nozzle block onto a cooled substrate, to form a patterned organic film. A device for carrying out the method is also provided. The device includes a source of organic vapors, a source of carrier gas and a vacuum chamber. A heated nozzle block attached to the source of organic vapors and the source of carrier gas has at least one nozzle adapted to eject carrier gas and organic vapors onto a cooled substrate disposed within the vacuum chamber.

Effect of different initial conditions on a turbulent round free jet

Abstract: Velocity measurements were made in two jet flows, the first exiting from a smooth contraction nozzle and the second from a long pipe with a fully developed pipe flow profile. The Reynolds number, based on nozzle diameter and exit bulk velocity, was the same (≃86,000) in each flow. The smooth contraction jet flow developed much more rapidly and approached self-preservation more rapidly than the pipe jet. These differences were associated with differences in the turbulence structure in both the near and far fields between the two jets. Throughout the shear layer for x<3d, the peak in the v spectrum occurred at a lower frequency in the pipe jet than in the contraction jet. For x≥3d, the peaks in the two jets appeared to be nearly at the same frequency. In the pipe jet, the near-field distributions of f(r) and g(r), the longitudinal and transverse velocity correlation functions, differed significantly from the contraction jet. The integral length scale Lu was greater in the pipe jet, whereas Lv was smaller. In the far field, the distributions of f(r) and g(r) were nearly similar in the two flows. The larger initial shear layer thickness of the pipe jet produced a dimensionally lower frequency instability, resulting in longer wavelength structures, which developed and paired at larger downstream distances. The regular vortex formation and pairing were disrupted in the shear layer of the pipe jet. The streamwise vortices, which enhance entrainment and turbulent mixing, were absent in the shear layer of the pipe jet. The formation of large-scale structures should occur much farther downstream in the pipe jet than in the contraction jet.

A new method for significantly reducing drop radius without reducing nozzle radius in drop-on-demand drop production

Abstract: The lack of a simple method for generating drops whose radii (Rd) are much smaller than those (R) of nozzles which produce them has heretofore been a major limitation of the drop-on-demand technique. Therefore, the only reliable way to reduce Rd to date has been to reduce R. A new method is reported which allows an order of magnitude reduction in drop volume while using the same nozzle. It is shown that the key to forming drops with Rd

Printhead assembly for an ink jet printer

Abstract: A printhead assembly for an ink jet printer includes an elongate pagewidth printhead having a plurality of nozzle arrangements. The printhead defines a plurality of ink supply passages in fluid communication with each respective nozzle arrangement. An elongate pagewidth ink distribution manifold is connected to said printhead, the manifold being in fluid communication with the ink supply passages and defining a plurality of ink inlets. An ink supply unit is connected to said manifold and defines a volume in which ink for the printhead is stored while being fed from the supply unit to the printhead, via the manifold. The ink supply unit includes a plurality of obstruction members that are positioned in the ink supply unit to inhibit excessive movement of ink in the ink supply unit as a result of movement of the printer.

A thermal-bubble-actuated micronozzle-diffuser pump

Abstract: A thermal-bubble-actuated micropump by the principles of liquid/vapor phase transition and nozzle-diffuser flow regulation is successfully demonstrated. The micropump consists of a resistive heater, a pair of nozzle-diffuser flow controller and a 1 mm in diameter, 50 /spl mu/m in depth pumping chamber. The actuation mechanism comes from periodically nucleating and collapsing thermal bubbles. A net flow is generated from the nozzle to the diffuser by the nozzle-diffuser flow controller. Two heater designs, single-bubble and dual-bubble actuation mode, have been investigated. In the single-bubble pumping mode, a maximum flow rate of 5 /spl mu/l/min is measured when the driving pulse is 250 Hz at 10% duty cycle under an average power consumption of 1 W. A similar flow rate of 4.5 /spl mu/l/min is achieved in the dual-bubble pumping mode, at the driving pulse of 5% duty cycle at 400 Hz with lower average power consumption, 0.5 W. The static pumping pressure is measured at a maximum value of 377 Pascal when the net volume flow rate is zero. As an application example in a microfluidic device, this valve-less micropump is used in a microfluidic system to enhance the fluid mixing by agitating the flows.

A Numerical Characterization of Particle Beam Collimation by an Aerodynamic Lens-Nozzle System: Part I. An Individual Lens or Nozzle

Abstract: Particle beams have traditionally been produced by supersonic expansion of a particle-laden gas through a single nozzle to vacuum However, it has been shown that, by passing the particle-laden gas

Processing system and processing method

Abstract: PROBLEM TO BE SOLVED: To provide a highly reliable processing system capable of switching the atmosphere at a high speed. SOLUTION: A processing container 12 provided with first and second air supply/exhaust ports 18 and 19 oppositely is turned about the center of a wafer W. Air supply nozzles 21a-21d and exhaust nozzles 22a-22d are arranged with a substantially constant interval around the processing container 12. Specified gases are supplied constantly from the air supply nozzles 21a-21d. In response to spinning of the processing container 12, the first and the second air supply/exhaust ports 18 and 19 are coupled sequentially with the air supply nozzles 21a-21d and the exhaust nozzles 22a-22d, and the interior of the processing container 12 is switched sequentially to a specified gas atmosphere. COPYRIGHT: (C)2004,JPO

Breakup and atomization of a kerosene jet in crossflow at elevated pressure

Abstract: The breakup, penetration, and atomization of a plain jet of kerosene Jet A-1 fuel in a non-swirling crossflow of air were investigated experimentally at test conditions relevant to LPP (Lean Premixed Prevaporized) combustion for gas turbines. Measurement techniques employed include time-resolved shadowgraphs, Mie-scattering laser light sheets, and Phase-Doppler-Anemometry (PDA). The nozzle diameter was 0.45 mm and its L/D ratio was 1.56. Air velocities lay between 50 m/s and 100 m/s, the air pressure range extended from 1.5 bar to 15 bar and the air temperature was around 290 K. Fuel flowrates were chosen so that the fuel-to-air momentum flux ratio q assumed mainly values between 2 and 18. Two different mechanisms of jet breakup could be discerned and correlations for the jet penetration and lateral dispersion close to the nozzle were derived. Furthermore, the penetration of the spray plume and its representative droplet diameters were determined. Finally, a simple, approximate model to predict liquid fuel penetration is presented.

Manufacturing device and the method of preparing for the nanofibers via electro-blown spinning process

Abstract: The invention relates to a nanofiber web preparing apparatus and method via electro-blown spinning. The nanofiber web preparing method includes feeding a polymer solution, which is a polymer dissolved into a given solvent, toward a spinning nozzle, discharging the polymer solution via the spinning nozzle, which is charged with a high voltage, while injecting compressed air via the lower end of the spinning nozzle, and collecting fiber spun in the form of a web on a grounded suction collector under the spinning nozzle, in which both of thermoplastic and thermosetting resins are applicable, the solution does not need to be heated and electrical insulation is readily realized.

Systems and processes for spray drying hydrophobic drugs with hydrophilic excipients

Abstract: Methods for preparing dry powders having hydrophobic and hydrophilic components comprise combining solutions of the components and spray drying them simultaneously in a spray dryer. The hydrophilic and hydrophobic component are separately dissolved in separate solvents and directed simultaneously through a nozzle, usually a coaxial nozzle, into the spray dryer. The method provides dry powders having relatively uniform characteristics.

Gas turbine combustor

Abstract: PROBLEM TO BE SOLVED: To form a premixed fuel-air mixture in a premixing dust, without causing abnormal combustion such as backfire or spontaneous ignition and the like in a gas turbine combustor that has the premixing duct of fuel and is a low NOx emission combustor. SOLUTION: This device has a swirler swirling combustion air and a fuel injection nozzle, and is provided with a boundary layer thickness-reducing means of a premixed fuel-air mixture on the sidewall of a premixing duct forming the premixed mixture of fuel and combustion air. Thereby, the development of the boundary layer of the premixed fuel-air mixture and the like on the sidewall is suppressed, and abnormal combustion, such as nonconforming backfires or spontaneous ignition, etc., of the premixing duct caused by the development of the boundary layer are prevented.

Gas port sealing for CVD/CVI furnace hearth plates

Abstract: A method and apparatus for sealing gas ports in CVD/CVI furnaces and processes is disclosed. A fluid direction nozzle (160) is positioned between a top lip (101) of a gas inlet port (100) delivering a reactant gas (G) to a furnace compartment (200) in a CVD/CVI furnace (10) and corresponding holes (151) of a CVD/CVI process apparatus such as a hearth plate (150). The fluid direction nozzle (160) reduces leakage of reactant gases (G) and ensures a smooth transition of gas flow direction between the gas inlet port (100) and the corresponding holes (151). CVD/CVI process times are significantly reduced with the use of the reusable/replaceable flow direction nozzles (160).

Axial flow turbine

Abstract: An axial flow turbine provided with a stage composed of a turbine nozzle and a turbine rotor blade arranged in an axial flow direction. Both end portions of a nozzle blade of the turbine nozzle are supported by a diaphragm inner ring and a diaphragm outer ring, and a flow passage is formed to have its diameter expanded from an upstream stage to a downstream stage. In such axial flow turbine, trailing edges at ends of the nozzle blade supported by the diaphragm inner ring and the diaphragm outer ring are curved as a curvature to an outlet side, and an intermediate portion between the trailing edges is formed to be straight.

Reflection of circumferential modes in a choked nozzle

Abstract: Small perturbations of a choked flow through a thin annular nozzle are investigated. Two cases are considered, corresponding to a ‘choked outlet’ and a ‘choked inlet’ respectively. For the first case, either an acoustic or entropy or vorticity wave is assumed to be travelling downstream towards the nozzle contraction. An asymptotic analysis for low frequency is used to find the reflected acoustic wave that is created. The boundary condition found by Marble & Candel (1977) for a compact choked nozzle is shown to apply to first order, even for circumferentially varying waves. The next-order correction can be expressed as an ‘effective length’ dependent on the mean flow (and hence the particular geometry of the nozzle) in a quantifiable way.For the second case, an acoustic wave propagates upstream and is reflected from a convergent–divergent nozzle. A normal shock is assumed to be present. By considering the interaction of the shock's position and flow perturbations, the reflected propagating waves are found for a compact nozzle. It is shown that a significant entropy disturbance is produced even when the shock is weak, and that for circumferential modes a vorticity wave is also present. Numerical calculations are conducted using a sample geometry and good agreement with the analysis is found at low frequency in both cases, and the range of validity of the asymptotic theory is determined.

Generation and Control of Tracer Particles for Optical Flow Investigations in Air

Abstract: The production of mono-disperse tracer particles with suitable properties for optical flow investigations , such as small size, spherical shape, smooth surface, appropriate density and diffraction index, non-evaporating and agglomerating, electrically neutral, non-toxic and easily removable, is a challenging task due to the sensitivity of the particle size distribution to the boundary conditions. In order to obtain general design and operating rules for atomizers which are mostly applied for air flows, this dependence is investigations here. It is shown that high concentrations of narrow band particle size distributions, with a mean diameter below 1 micrometer, can easily be generated by means of multi-hole nozzles under overcritical pressure conditions, when the kinetic energy, transferred into the seeding liquid through the nozzle exits, is well balanced with the liquid volume inside the atomizer. In addition, flow visualization pictures are presented which permit a useful assessment of the functioning of the nozzles and reveal operating features of the atomizers which were not previously known. In particular, it will be shown that existing explanations of the importance of certain design features of the Laskin nozzle are of minor importance for the generation of appropriate tracer particles.

Ink jet print head, inkjet printer including the inkjet print head, and method of manufacturing inkjet print head

Abstract: An inkjet print head includes one nozzle sheet (23) and a plurality of head chips (25) including a plurality of heaters. The nozzle sheet (23) is formed of an electroformed metal layer made of nickel or a material comprising nickel, and has discharge nozzle rows for respective colors disposed so that the discharge nozzles are in staggered arrangements and so that each set of discharge nozzles partly overlaps another set of discharge nozzles in a sheet-feed direction. The head chips are positioned at and affixed to a growth surface side of the nozzle sheet (23) in staggered arrangements so that the positions of the discharge nozzles and the positions of the heaters correspond to each other. Accordingly, reduction in printing quality caused by displacement of any of the discharge nozzles is prevented from occurring, and landing positions of discharged ink on a recording sheet are stabilized.

Computational investigation of arc behavior in an auto-expansion circuit breaker contaminated by ablated nozzle vapor

Abstract: PC-based arc modeling taking account of the effects of nozzle ablation and the mixing process of PTFE vapor with SF/sub 6/ has been carried out for a full-scale auto-expansion circuit breaker with a moving contact. An equation to calculate the PTFE concentration in the mixture is introduced together with overall mass, momentum, and energy conservation equations for the mixture. The thermodynamic and transport properties of SF/sub 6/-PTFE vapor mixture calculated by the transport theory are given. An empirical relationship between radiation reabsorption factor and the relevant arcing parameters (nozzle size and instantaneous arcing current) has been employed to make predictions. The features of temperature, pressure, PTFE mass concentration, and flow fields during the whole arcing period are discussed. It is shown that the energy brought into the expansion volume by the hot PTFE vapor is mainly responsible for the pressure buildup. The propagation of the pressure wave in the expansion volume is responsible for the pressure peaks in the second loop of arcing. The predicted arc voltage and pressure variation are compared with the test results and with those predicted using the thermodynamic and transport properties of pure SF/sub 6/. Results show that the use of the properties of SF/sub 6/-PTFE vapor mixture substantially improves the agreement between the predicted and measured pressure rise in the expansion volume.

Tortuous path quiet exhaust eductor system

Abstract: A tortuous path quiet exhaust eductor system may be mounted to a gas turbine engine, such as commercial aircraft APU. The system includes an oil cooler, eductor primary nozzle, oil cooler air nozzle, and surge air dump nozzle. The primary nozzle, oil cooler air nozzle, and surge air dump nozzle direct exhaust flow to entrain APU compartment cooling air, oil cooling air and surge air in a direction having both radial and axial components with respect to the APU centerline axis. The exhaust flow is directed into an eductor mixing duct angled away from the centerline axis and then is turned to enter an exit duct angled toward the centerline axis so that direct line of sight acoustic paths from the tail pipe exit to the turbine exit are blocked, suppressing core noise. The tail pipe ducts may be acoustically treated, further enhancing noise suppression.

Numerical simulation of premixed turbulent methane combustion

Abstract: With adaptive-grid computational methodologies and judicious use of compressible and low Mach number combustion models, we are carrying out three-dimensional, time-dependent direct numerical simulations of a laboratory-scale turbulent premixed methane burner. In the laboratory experiment, turbulence is generated by a grid located in the throat of a 50mm diameter circular nozzle; swirl is be introduced by four tangential air jets spaced uniformly around the circumference of the nozzle just above the turbulence grid. A premixed methane flame is stabilized above the nozzle in the central core region where a velocity deficit is induced7the swirling flow. The time-dependent flow field inside the nozzle, from the turbulence grid and the high-speed jets, to the nozzle exit plane is simulated using an adaptive-grid embedded-boundary compressible Navier-Stokes solver. The compressible calculation then provides time-dependent boundary conditions for an adaptive low Mach number model of the swirl-stabilized premixed flame. The low Mach model incorporates detailed chemical kinetics and species transport using 20 species and 84 reactions. Laboratory diagnostics available for comparisons include characterizations of the flow field just down stream of the nozzle exit plane, and flame surface statistics, such as mean location, wrinkling and crossing frequencies.

Cold spray nozzle mach number limitation

Abstract: The classic one-dimensional isentropic flow approach is used along with a two-dimensional axisymmetric numerical model to show that the exit Mach number of a cold spray nozzle should be limited due to two factors. To show this, the two-dimensional model is validated with experimental data. Although both models show that the stagnation temperature is an important limiting factor, the one-dimensional approach fails to show how important the shock-particle interactions are at limiting the nozzle Mach number. It is concluded that for an air nozzle spraying solid powder particles, the nozzle Mach number should be set between 1.5 and 3 to limit the negative effects of the high stagnation temperature and of the shock-particle interactions.

Microfluidic array devices and methods of manufacture and uses thereof

Abstract: Microfluidic nozzle array devices are provided with the body of each device having at least one nozzle extending outwardly from one surface of the body. Each nozzle includes a tip opening having a diameter of equal to or less than about 100 μm, preferably 50 μm, and more preferably 20 μm and an outer diameter of nozzle is equal to or less than about 150 μm, preferably 100 μm, and more preferably 50 μm. The microfluidic nozzle array devices are fabricated using an injection molding process and find particular utility in a wide range of applications, including but not limited to nanospray/electrospray applications, mass spectrometer applications, optical spectrometry applications, spotting applications (i.e., DNA or protein array), etc.

Appearance of Restricted Shock Separation in Rocket Nozzles

Abstract: Uncontrolled flow separation in nozzles of rocket engines is not desired because it can lead to dangerous lateral forces. Different origins for side loads were identified in the past. Meanwhile, it is proven that in thrust-optimized or parabolic nozzles, a major side load occurs as a result of the transition of separation pattern from free shock separation to restricted shock separation and vice versa. 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 nozzle axis. To prove the transition effect as main side-load driver, a subscale test campaign has been performed. Two different nozzle contours, a thrust-optimized and a truncated ideal nozzle with equal performance data, were tested. Highest side loads were measured in the thrust-optimized nozzle, when the separation pattern changes from free to restricted shock separation. Side loads measured in the truncated ideal nozzle were only about one-third as high as in the thrust-optimized nozzle.

Thermally actuated ink jet printing mechanism having a series of thermal actuator units

Abstract: An inkjet nozzle arrangement includes a nozzle chamber having an fluid ejection nozzle in one surface of the chamber; a paddle vane located within the chamber, the paddle vane being adapted to be actuated by an actuator device for the ejection of fluid out of the chamber via the fluid ejection nozzle; and a thermal actuator device located externally of the nozzle chamber and attached to the paddle vane the thermal actuator device including a plurality of separate spaced apart elongated thermal actuator units. The thermal actuator units are constructed from multiple layers utilizing a single mask to etch the multiple layers.

Ink jet printing method

Abstract: PROBLEM TO BE SOLVED: To provide an ink jet recording method providing a significantly different deflection angle useful for a thermal operation continuous ink jet print head and using a specific ink SOLUTION: The ink jet recording method comprises steps (a) for preparing an ink jet printer ejecting a continuous flow of ink jet ink from a nozzle in response to a digital data signal, (b) for loading an ink jet recording element to the printer, (c) for loading an ink jet ink composition containing a thermally responsive polymer material to the printer, and (d) for ejecting ink from the thermal operation continuous ink jet print head to one ink jet recording element in response to the digital data signal

Development and Characterization of Hartmann Tube Fluidic Actuators for High-Speed Flow Control

Abstract: An in-depth investigation of the Hartmann tube (HT) was carried out to gain a better understanding of and the effects of various parameters on its output flow characteristics. The HT used in this work consisted of an underexpanded jet directed into a close-ended cylindrical tube of the same diameter. The effects of tube depth, separation distance between the tube and the nozzle, and the jet Mach number were explored. Experiments were also performed on an HT fluidic actuator (HTFA). The HTFA operates under the same principles as the HT, except a major portion of the area between the nozzle and tube is shielded off, so that it can be used as a pulsating injector for flow control. Dynamic pressure measurements in the near field and microphone measurements in the far field provided temporal and spectral data. Instantaneous and phase-averaged images of the flow were obtained to explore the nature of turbulence structures within the flow. Limited hot-wire measurements were performed to characterize the velocity fluctuations at the exit of the HTFA