Nozzle

About: Nozzle is a research topic. Over the lifetime, 158675 publications have been published within this topic receiving 893026 citations. The topic is also known as: spout.

Ultrasonic spray nozzle and method

Abstract: An ultrasonic spray nozzle includes a piezoelectric transducer which develops mechanical vibrations in response to an applied periodic electrical potential. The vibrations are mechanically amplified and propagate to an atomizing surface over which fluid to be atomized is discharged by an internal fluid passage. Maximum vibrational amplitude of the atomizing surface is achieved when the frequency of the applied electrical potential equals the natural resonant frequency of the nozzle. A parameter of the applied electrical potential, such as frequency, is periodically varied such that the vibrational amplitude of the atomizing surface is periodically increased and decreased. Fluid atomization is reduced during periods of reduced vibrational amplitude permitting fluid to be distributed with greater uniformity onto the atomizing surface. Such uniform distribution results in a significant improvement in the definition of the spray pattern produced by the nozzle during periods of increased vibrational amplitude. To further enhance uniform fluid distribution, auxiliary fluid passages are provided through the atomizing surface.

Characterization of d.c. plasma torch voltage fluctuations

Abstract: The arc root fluctuations at the anode-nozzle of a d.c. plasma spray torch with a special configuration of the electrodes allowing to work with the same gas flowrate with nozzle diameters ranging from 6 to 10 mm were systematically studied. The plasma gas was Ar/H2 (25 vol % H2), the current was varied between 200 and 600 A and the plasma gas flowrate between 24 and 80 slm. After 30–60 mn working the nozzle wall started to be sufficiently eroded to have a stagnant arc spot which lived until arcing created another one. It was shown that the life time of the upstream arc spots were 30–40 % longer than the downstream ones which could play an important role in the electrode erosion. Dimensional analysis allowed to find a relationship between the nozzle diameter D, the arc current I and gas flow rate G and the mean spot lifetime which is closely connected with the difference between D and the electrical diameter of the arc column. The comparison of voltage signal and light emission at a point of the plasma jet close to the nozzle exit on its axis allowed to determine the mean electrical field within the plasma column and the mean position of the arc root. The comparison with the electrode erosion area for well defined conditions showed a good correlation with the calculated arc root position.

Ink jet printer with a cleaning apparatus for removing hardened ink from a nozzle plate of a print head

Abstract: An ink jet printer in which hardened ink is readily and reliably removed from a nozzle plate. The ink jet printer includes a print head having a plural number of nozzle openings arrayed in the width direction of a recording paper, a head drive circuit for selectively outputting a first signal to cause a stream of ink droplets at a speed suitable for print and a second signal to cause ink to ooze through each nozzle opening, and a cleaning device with a rubbing function and which is usually positioned in a nonprinting region, but is movable in the longitudinal direction of the print head and with respect to a nozzle plate. In a cleaning mode, the cleaning device is operated while oozing ink from the nozzle openings. The hardened ink on the nozzle plate is dissolved by the oozing ink, and then removed therefrom through the rubbing and wiping operations of the cleaning device.

Acoustics and Thrust of Quiet Separate-Flow High-Bypass-Ratio Nozzles

Abstract: TheNASAGlennResearchCenterrecentlycompletedanexperimentalstudytoreducethejetnoisefrommodern turbofan engines. The study concentrated on exhaust nozzle designs for high-bypass-ratio engines. These designs modie ed the core and fan nozzles individually and simultaneously. In comparison with chevrons, tabs appeared to be an inefe cient method for reducing jet noise. Data trends show that interaction between fan e ow and the core cowl could strongly impact noise and cruise performance irrespective of the mixing device installed. The study demonstrates that modie cations of the core nozzle are generally more advantageous than of the fan nozzle. Even greater advantage in noise reduction and associated cruise thrust penalties is demonstrated through simultaneous modie cation of both nozzles. Thebestnozzledesign had a 0.06% cruisethrustlossand, corrected fortakeoff thrust loss, a 2.7-EPNdB reduction for the effective perceived noise level metric. This design simultaneously employed chevrons on the core and fan nozzles. Last, e ve nozzle cone gurations with cruise thrust loss of less than 0.5% and noise reductions of over 2.5 EPNdB are identie ed as candidates for full-scale engine and e ight demonstrations.

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.