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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.


Papers
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Journal ArticleDOI
TL;DR: In this article, the authors measured droplet sizes and velocities at 0.50 m below the nozzle using a PDPA laser-based measurement setup, and the effects of nozzle type (standard, low-drift, and air-inclusion), nozzle size (ISO 02, 03, 04, and 06) and operating pressure (2.0, 3.0 and 4.0 bar) were tested.
Abstract: The quality of agricultural sprays plays an important role in the application of plant protection products. For 13 nozzle-pressure combinations, droplet size and velocity characteristics were measured 0.50 m below the nozzle using a PDPA laser-based measurement setup. Nozzles were mounted on a transporter to sample the whole of the spray fan. The effects of nozzle type (standard, low-drift, and air-inclusion), nozzle size (ISO 02, 03, 04, and 06) and operating pressure (2.0, 3.0, and 4.0 bar) were tested. Measured droplet sizes and velocities were related, and both were affected by nozzle type, size, and operating pressure. Droplet velocities at 0.50 m were determined by their size and initial ejection velocity. In general, bigger droplet sizes correspond with higher droplet velocities, and smaller droplets with lower droplet velocities. Important differences in velocities were observed depending on the nozzle type and size, both affecting the ejection velocity. For the same droplet size, droplet velocities were highest for the flat-fan nozzles, followed by the low-drift nozzles and the air-inclusion nozzles (because of the lower ejection velocities caused by pre-orifice and Venturi effects). Similarly, the bigger the ISO nozzle size, the faster were the droplets of the same size. Droplet velocities of the larger droplet sizes (>400 µm) varied from about 4.5 to 8.5 m s-1 depending on the nozzle type and size. Below 400 µm, droplet velocities consistently decreased with the decrease in droplet size, and vary from 0.5 to 2 m s-1 depending on the nozzle type and size. All this information is very useful with regard to crop penetration, the risk of spray drift, and the quantity and distribution of the deposit on the target.

119 citations

Patent
Robert T. Mains1
28 Sep 1992
TL;DR: In this paper, a gas turbine fuel nozzle and method of fuel flow provide resistance to coking of the fuel by means of a multiple passage heat transfer cooling circuit, which can protect engines with both single tip and dual tip nozzles.
Abstract: A gas turbine fuel nozzle and method of fuel flow provide resistance to coking of the fuel by means of a multiple passage heat transfer cooling circuit. Fuel streams to primary and secondary sprays of pilot and main nozzle tips are arranged to transfer heat between the pilot primary fuel stream and each of the main secondary fuel stream and the pilot secondary fuel stream. This protects the fuel in the streams from coking during both low flow, lower engine heat conditions and high flow, high engine heat conditions. This nozzle and flow can protect engines with both single tip and dual tip nozzles.

119 citations

Journal ArticleDOI
TL;DR: In this article, the formation of liquid drops of incompressible Newtonian fluids from a simple capillary tube by imposing a transient flow rate upstream of the nozzle exit is studied.
Abstract: Motivated by the desire to improve the theoretical understanding of drop-on-demand (DOD) ink-jet printing, a computational analysis is carried out to simulate the formation of liquid drops of incompressible Newtonian fluids from a simple capillary tube by imposing a transient flow rate upstream of the nozzle exit. Since the flow in a typical ink-jet nozzle is toward the nozzle outlet during part of the time and away from the nozzle outlet at other times, an inflow rate is adopted here that captures the essential physics and is given in dimensionless form by Q=(πWe∕2)sinΩt, where We is the Weber number (inertial/surface tension force), Ω is the frequency, and t is time. The dynamics are studied as functions of We, Ω, and the Ohnesorge number Oh (viscous/surface tension force). For a common ink forming from a nozzle of 10μm radius, Oh=0.1. For this typical case, a phase or operability diagram in (We,Ω)-space is developed that shows that three regimes of operation are possible. In the first regime, where We ...

119 citations

Journal ArticleDOI
TL;DR: In this paper, a simple burner model is used to scale both the direct and indirect noise in aeroengines, and the analytical relations for the combustion and the nozzle provide simple scaling laws for direct combustion noise ratio as a function of the Mach number.
Abstract: Core noise in aeroengines is due to two main mechanisms: direct combustion noise, which is generated by the unsteady expansion of burning gases, and indirect combustion noise, which is due to the acceleration of entropy waves (temperature fluctuations generated by unsteady combustion) within the turbine stages. This paper shows how a simple burner model (a flame in a combustion chamber terminated by a nozzle) can be used to scale direct and indirect noise. An analytical formulation is used for waves generated by combustion. The transmission and generation of waves through the nozzle is calculated using both the analytical results of Marble and Candel (Marble, F. E., and Candel, S., "Acoustic Disturbances from Gas Nonuniformities Convected Through a Nozzle," Journal of Sound and Vibration, Vol. 55, 1977, pp. 225-243.) and a numerical tool. Numerical results for the nozzle verify and extend the analytical approach. The analytical relations for the combustion and the nozzle provide simple scaling laws for direct and indirect noise ratio as a function of the Mach number in the combustion chamber and at the nozzle outlet.

119 citations

Patent
30 Aug 2007
TL;DR: In this paper, an integrated-electrode nozzle system that is directly connected to an electrode and a counter-Electrode is presented, which is capable of printing nanofeatures or microfeatures.
Abstract: Provided are high-resolution electrohydrodynamic inkjet (e-jet) printing systems and related methods for printing functional materials on a substrate surface. In an embodiment, a nozzle with an ejection orifice that dispenses a printing fluid faces a surface that is to be printed. The nozzle is electrically connected to a voltage source that applies an electric charge to the fluid in the nozzle to controllably deposit the printing fluid on the surface. In an aspect, a nozzle that dispenses printing fluid has a small ejection orifice, such as an orifice with an area less than 700 μm 2 and is capable of printing nanofeatures or microfeatures. In an embodiment the nozzle is an integrated-electrode nozzle system that is directly connected to an electrode and a counter-electrode. The systems and methods provide printing resolutions that can encompass the sub-micron range.

119 citations


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Performance
Metrics
No. of papers in the topic in previous years
YearPapers
20231,827
20223,448
20211,700
20203,921
20195,309
20186,486