Relevant bibliographies by topics / Nozzles

Academic literature on the topic 'Nozzles'

Author: Grafiati
Published: 4 June 2021
Last updated: 29 July 2024

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Journal articles on the topic "Nozzles"

1

Zhang, Shuce, Xueheng Tao, Jinshi Lu, Xuejun Wang, and Zhenhua Zeng. "Structure Optimization and Numerical Simulation of Nozzle for High Pressure Water Jetting." Advances in Materials Science and Engineering 2015 (2015): 1–8. http://dx.doi.org/10.1155/2015/732054.

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Three kinds of nozzles normally used in industrial production are numerically simulated, and the structure of nozzle with the best jetting performance out of the three nozzles is optimized. TheR90 nozzle displays the most optimal jetting properties, including the smooth transition of the nozzle’s inner surface. Simulation results of all sample nozzles in this study show that the helix nozzle ultimately displays the best jetting performance. Jetting velocity magnitude alongYandZcoordinates is not symmetrical for the helix nozzle. Compared to simply changing the jetting angle, revolving the jet issued from the helix nozzle creates a grinding wheel on the cleaning surface, which makes not only an impact effect but also a shearing action on the cleaning object. This particular shearing action improves the cleaning process overall and forms a wider, effective cleaning range, thus obtaining a broader jet width.
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2

Baha, Vadym, Ivan Pavlenko, Kamil Židek, and Olaf Ciszak. "Ensuring the Abrasive Jet Machining Efficiency Using a Nozzle with a Perforated Insert." Machines 12, no. 5 (May 16, 2024): 347. http://dx.doi.org/10.3390/machines12050347.

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Ejector-cleaning devices for abrasive jet machining have various practical applications. The working nozzle is one of the device’s key elements affecting the treated surface quality. There arises the necessity for new approaches to achieving an efficiency increase in abrasive jet equipment nozzles, namely their design improvement and further development of a new, relatively cheap but effective technology for their manufacturing and maintenance. This technology should allow for the high durability of nozzles without being essential for the hardness or wear resistance parameters of the material used for manufacturing. The nozzle should be designed as a long-length perforated insert to allow for radial airflow, forcing the abrasive material (river sand) from the inner walls of the nozzle’s working surface to reduce its friction with the abrasive material. This will result in new wear-out conditions, providing an essential decrease in the wear-out of a nozzle’s working surface. The article aims to develop a more effective design for the working nozzle based on the perforated insert application. The task was set to provide a more detailed experimental and theoretical study of the processes in perforated nozzles to improve their effectiveness. The research resulted in a new design for nozzles with higher efficiency.
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3

Wang, Guobin, Tongsheng Zhang, Cancan Song, Xiaoqing Yu, Changfeng Shan, Haozheng Gu, and Yubin Lan. "Evaluation of Spray Drift of Plant Protection Drone Nozzles Based on Wind Tunnel Test." Agriculture 13, no. 3 (March 6, 2023): 628. http://dx.doi.org/10.3390/agriculture13030628.

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The use of drones in agriculture is expanding at a brisk pace in crop production due to the superiority in precision, efficiency, and safety of their applicators. However, their potential drift risk also raises concern for users and regulatory authorities. The method of wind tunnel research can effectively evaluate the weighted influence of each drift factor, especially the drift characteristics of the nozzle and spray solution. Based on the wind tunnel test results, centrifugal nozzles have a higher drift risk than hydraulic nozzles, even with a similar DV50. The cumulative drift rate of the centrifugal nozzle at 2 m downwind was 90.1% compared to the LU12001 nozzle’s 40.6% under the wind speed of 3.5 m/s. Compared with the same coding as the flat fan hydraulic nozzle, the IDK nozzle can effectively reduce the drift rate. For the tested nozzles, DV50 and wind speed had a linear relationship with drift rate, and the sampling location had an exponential or logarithmic relationship with drift rate. Spray adjuvants, especially modified vegetable oils, had a significant effect on reducing the amount of drift. The results of this experiment provide a reference for the selection of nozzles and the addition of spray adjuvants. Further clarifying the spray drift characteristics of drones until a drift prediction model is available is still the focus of research.
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4

Liu, Shi Nian, Wei Su, and Zeng Fu Wei. "Flow Field Simulation of the Nozzle and the Influence of Size." Applied Mechanics and Materials 437 (October 2013): 47–50. http://dx.doi.org/10.4028/www.scientific.net/amm.437.47.

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The nozzle is one of the critical parts in the dry-ice blasting system, spray nozzle's structure and the air supersonic free jet flow field take big influence on cleaning efficiency during the blasting process. Inner flow field of different size nozzles and the flow field of jet flow sprayed by nozzles were simulated with software Fluent, which obtained the distribution results of pressure and velocity of fluid. The result indicated that the supersonic underexpanded jet take place in the nozzle outlet and the shock wave is gained as the pressure at the nozzle exit is greater than the atmospheric pressure. With increasing of the nozzle size, the velocity decrease of airflow become slower, the shock wave transmission distance increase and deduce the stability of the jet flow.
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5

Wang, Zhi Wu, Kun Zhang, and Long Xi Zheng. "Numerical Simulation of the Nozzle Angles Effect on the Pressure at Thrustwall and Nozzle Outlet of PDE." Applied Mechanics and Materials 705 (December 2014): 92–95. http://dx.doi.org/10.4028/www.scientific.net/amm.705.92.

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In order to investigate the effects of nozzles with different angles on PDE performance, PDE with nozzles of different convergent and divergent angles were simulated and propane-air mixture was used. The simulation results indicated that the effects of nozzles with different angles on the pressure at the thrustwall of PDE and nozzle outlet were not the same. The pressure at the thrustwall and nozzle outlet of PDE with convergent nozzles was higher than that with divergent nozzles, and the pressure peak appeared earlier in the case of convergent nozzles. The peak value of the pressure at the nozzle outlet increased and appeared ahead of time as the convergent angle increased. The peak value of the pressure at the nozzle outlet increased and the evacuation time was prolonged with convergent nozzles. The pressure at the nozzle outlet dropped quickly and the evacuation time was shortened with divergent nozzles.
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6

Liu, Li Li, and Jian Xin Deng. "Study on Erosion Wear Mechanism of SiC/(W,Ti)C Gradient Ceramic Nozzle Material." Key Engineering Materials 375-376 (March 2008): 440–44. http://dx.doi.org/10.4028/www.scientific.net/kem.375-376.440.

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Idea of functionally gradient material (FGM) theory was used to the design of ceramic nozzle. The purpose was to increase the erosion wear resistance at the entrance of the nozzle in dry sand blasting processes. The SiC/(W,Ti)C gradient ceramic nozzles fabricated by conventional hot pressing. The erosion behavior of the SiC/(W,Ti)C gradient ceramic nozzles were investigated in comparison with the common homologous ceramic nozzles. The experimental results have shown that the ceramic nozzles with a gradient structure have superior erosion wear resistance to that of the common homologous ceramic nozzles under the same test conditions. It was shown that the mechanical properties of the gradient ceramic nozzle materials were greatly improved in comparison with that of the common homologous nozzles. The surface Vickers hardness and indentation fracture toughness of gradient ceramic nozzle were greatly improved compared with that of the common homologous nozzles. Therefore, it is indicated that gradient structures in ceramic nozzles is an effective way to improve the erosion wear resistance of the common homologous nozzles.
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7

Fu, Lei, Shuai Zhang, and Yao Zheng. "Design and Verification of Minimum Length Nozzles with Specific/Variable Heat Ratio Based on Method of Characteristics." International Journal of Computational Methods 13, no. 06 (November 2, 2016): 1650034. http://dx.doi.org/10.1142/s0219876216500341.

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Two-dimensional (2D) and axisymmetric minimum length nozzles (MLN) with constant and variable specific heat were strictly designed using the method of characteristics. Requirements for the exit Mach number and flow field uniformity were proposed for the nozzles design. In solutions to kernel zone flow field reported previously, violent vibrations of upper wall discrete points at the inlet were observed. Meanwhile, slight compressions could be observed in the flow field of axisymmetric nozzles designed by those methods. In this study, we proposed a novel technique in which the inlet grid is intensified to overcome the limitations mentioned above. Additionally, methods based on conservation of mass and eliminating wave theory were proposed to determine the contour of the nozzle’s upper wall. Inviscid numerical simulations by CFD revealed that the proposed nozzle could meet the requirements for exit Mach number and flow field uniformity in various situations, and axisymmetric nozzles designed from eliminating wave theory exhibited better flow field compared with those designed from conservation of mass.
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8

Vong, Chin Nee, and Peter Ako Larbi. "Development and Prototype Testing of an Agricultural Nozzle Clog Detection Device." Transactions of the ASABE 64, no. 1 (2021): 49–61. http://dx.doi.org/10.13031/trans.13519.

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HighlightsPrototypes of an agricultural nozzle clog detection system (for 18 nozzles) have been successfully developed.Spray quality characteristics (droplet size, pattern, and coverage) were not significantly affected when testing the device with extended-range nozzles (TeeJet XR8004).Most of the spray quality characteristics were significantly affected when testing the device with ultra low-drift nozzles (John Deere PSULDQ2004).Abstract. Agricultural nozzles are the main components that perform the spraying of agrochemicals, and their proper functionality is a key element for uniform spray application on crops. Because nozzles have small orifices, they can become clogged when there is debris from the agrochemical in the tank. Nozzle clogging during spray application results in poor pest and weed management and increased cost for re-spraying the affected crop row. Measures used to prevent nozzles from clogging include using screens or strainers to filter out debris before it reaches the nozzle tip, as well as performing regular checks on the nozzles. However, nozzle clogging still occurs during spraying despite the precautions taken. Thus, a device that can detect nozzle clogging during spraying is necessary to enable a quicker response that will ensure uniform application across each row of the crop. A novel, patented device for detecting clogged nozzles that is externally attachable to each nozzle on a sprayer boom was developed in the Precision Application Technology Lab at Arkansas State University. The main objective of this article is to present a general description of this prototype nozzle clog detection device and the nozzle clog detection system. Spray droplet size and pattern tests under controlled conditions and spray coverage tests under field conditions were conducted with and without the device to determine if there were significant differences in droplet size, spray pattern, or spray coverage between using and not using the device. The tests demonstrated that this new technology has potential for detecting clogged nozzles without significantly influencing spray quality for extended-range nozzles but not for ultra low-drift nozzles. To increase the reliability of the performance of this new technology, further improvements in the design need to be considered. Keywords: Clogged nozzle, Detection, Droplet size, Prototype device, Spray coverage, Spray pattern.
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9

PANDA, ANTON, VOLODYMYR MYKOLAJOVYCH ANISIMOV, VOLODYMYR VOLODYMYROVYCH ANISIMOV, IVETA PANDOVA, ANTON KLYMENKO, and PETER ERMAKOV. "CAVITATION NOZZLES WITH EXPANSION CHAMBER." MM Science Journal 2022, no. 4 (November 16, 2022): 6020–25. http://dx.doi.org/10.17973/mmsj.2022_11_2022050.

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An expansion chamber for narrow part of cavitation nozzles is developed. Designs of cavitation nozzles with expansion chamber based on cylindrical nozzle and Venturi nozzle are proposed. The results of calculations of the fluid flow in the presented nozzles show the areas in nozzle, where cavitation is generated, their number, form and power. The plot of volume fraction of vapor phase shows the causes of an increase in the intensity of cavitation in new nozzles with expansion chamber. The main of them is that due to introduction of the expansion chamber, a little area of cavitation generation in the narrow part of cavitation nozzle turns to large one, that causes significant increase in cavitation intensity. The results of comparative experimental studies, which confirm the superiority of cavitation nozzles with the expansion chamber over the basic ones, show that cavitation nozzle with expansion chamber can provide 3 times higher intensity of cavitation, than basic cylindrical nozzle. Also, cavitation nozzle with expansion chamber on the basis of Venturi nozzle can provide 1.5 times higher cavitation intensity, than basic Venturi nozzle.
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10

Lipnický, Marek, and Zuzana Brodnianská. "The Effect of a New Approach to Cooling the External Heat Exchange Surfaces of a Car Cooler with Air Nozzles on the Cooling Process." Applied Sciences 14, no. 6 (March 7, 2024): 2227. http://dx.doi.org/10.3390/app14062227.

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The paper deals with an experimental investigation of a new approach for cooling the external heat exchange surfaces of a cooler using an air pressure nozzle system. The G12+ coolant (50:50 ethylene glycol/water concentrate) is heated to an operating temperature of 80 °C and cooled by a cooler. Three ways of forced cooling of the external heat exchange surfaces of the cooler are experimentally compared—fan, nozzles, and a combination of nozzles and fan. The spacing between the nozzles and the cooler is variable from 60 to 170 mm in inline and staggered nozzle arrangements. Coolant temperatures in the cooler inlet and outlet pipes are recorded by thermistors. The air pressure nozzle system achieved an improvement in the cooling process compared to a conventional fan. At a spacing of 160 mm, the heat exchange surface is completely covered by the air flow, which leads to a reduction in cooling time and an increase in the temperature difference. The maximum temperature difference of 28.84 °C and 16.90 °C for staggered arrangement of nozzles at a spacing of 160 mm are achieved for the combination of nozzles with fan and nozzles, respectively. When comparing 60 mm and 160 mm spacing, there was an increase in thermal performance of 70.3%, 55.99%, 6.20%, and 1.83% for inline nozzles, staggered nozzles, fan with inline nozzles, and fan with staggered nozzles, respectively. The air nozzle system fully replaces the fan in the cooling process and achieves improved heat dissipation, making the cooling process significantly shorter and more efficient. In addition, the air nozzle system can also be used as an additional equipment for intensification of heat dissipation in combination with the fan.
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Dissertations / Theses on the topic "Nozzles"

1

Rajakuperan, E. "Experimental And Computational Investigations Of Underexpanded Jets From Elliptical Sonic Nozzles." Thesis, Indian Institute of Science, 1994. https://etd.iisc.ac.in/handle/2005/158.

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Three dimensional nozzles and jet flows have attracted the attention of many researchers due to their potential application to many practical devices. Rectangular nozzles are considered for short/vertical take off and landing aircrafts for achieving powered lift. Axisymmetric nozzles with lobes, tabs or slots and elliptical nozzles are considered for noise reduction in aircrafts and mixing augmentation in airbreathing rockets. Interaction of supersonic jets with solid surface, as in the case of retro and ullage rockets in launch vehicles and interaction of multiple jets as in the case of launch vehicles with multiple booster rockets/multiple nozzle engines are of practical importance. Design of rockets and aircrafts employing these nozzles needs the understanding of the structure and behaviour of the complex three dimensional supersonic jets issuing from these nozzles. The problem is so complex that different investigators have addressed only some specific aspects of the problem and there is much more to be done to fully understand these flows. For example, in the case of rectangular nozzle with semi circular ends (known as elliptical nozzle), the investigations have been limited to a single nozzle of aspect ratio 3,0 and pressure ratio (ratio of the total pressure to ambient pressure) 3.0. Further, the measurements were made in the far field subsonic region beyond a distance of 20 times the equivalent nozzle radius (RJ. For the present study, the elliptical sonic nozzle of the type mentioned above was chosen, as it offered simplicity for manufacturing and carrying out computations, but has all the complex features associated with the three dimensional jets. A systematic study to understand the mean flow structure and the effect of important governing parameters like ratio and pressure ratio on the flow development process of the jet issuing from Navier-Stokes equations. The experimental study revealed many interesting flow features. It was found that the Underexpanded jet issuing from elliptical sonic nozzle spreads rapidly in the minor axis plane while it maintains almost constant width or contracts in the major axis plane. However, the gross spreading of this jet is much higher compared to the axisymmetric jet. The higher spreading rates experienced in the minor axis plane compared to the major axis plane of this 'et, results in the jet width in the minor axis plane to become higher than that in the major axis plane. The longitudinal location, where this occurs is called the axis switching location. This kind of axis switching phenomenon is known to exist for subsonic elliptical jets. However, for the present supersonic jets, the axis switching locations are much closer to the nozzle exit compared to the subsonic cases reported. It was further found that this location strongly depends on the pressure and aspect ratios. A critical pressure ratio was found to exist for each nozzle at which the axis switching location is the farthest. Above the critical pressure ratio, the axis switching location was observed to move upstream with the increase in the pressure ratio and is controlled by the complex interactions of shock and expansion waves near the nozzle exit. Below the critical pressure ratio, the axis switching location moves upstream with the decrease in pressure ratio and is controlled by some kind of instability in the minor axis plane. The shock structure present in the underexpanded jet from an elliptical nozzle was also observed to depend on both pressure and aspect ratios. For some aspect ratios and pressure ratios, the shock pattern observed in both the major and minor axis planes are similar to that of an axisymmetric jet, where the incident barrel shock and the Mach reflection (from the edges of the Mach disk) are present. But for all other cases, this shock continues to be seen only in the major axis plane. Whereas, in the minor axis plane, the incident shock is absent in the shock pattern. Detailed measurement in the jet cross sectional planes, for the case of aspect ratio 2.0 nozzle, shows that the cross sectional shape changes along the length and it becomes almost a circle at the axis switching location. Further downstream, the jet spreads rapidly in the minor axis plane whereas no significant change in the width of the jet in the major axis plane is observed. Far downstream, the jet boundary appears like a distorted ellipse with its major and minor dimensions lying respectively in the minor and major axis planes of the nozzle. The elongated shape of the jet cross sections at locations downstream of the axis switching point gives the impression that the entire flow in the major axis plane is turned towards the minor axis plane. This effect appears to be predominant at high pressure ratios. The computed near field shock structure in the planes of symmetry, pitot pressure distributions, cross sectional shape of the jet and the spreading pattern agree very well with the experimental results. In addition to this, the present computational method gives the detailed near field flow structure including the azimuthal extent of the incident shock, cross flow details and distributions of flow variables. It is shown that the present inviscid methodology can also predict the axis switching point accurately if it occurs before the formation of the Mach disk and it demonstrates that the jet growth phenomenon in the near field, atleast, is mainly controlled by the inviscid flow process. The computed results have shown that changes in the jet cross sectional shape in the near field is caused mainly by the interaction of compression and expansion waves with each other and with the constant pressure boundary. The inviscid method seems to be able to capture the complicated secondary cross flow structure (indicating presence of longitudinal vortices) of the elliptical jet. The complex mean flow structure in the near field region of the jet issuing from elliptical nozzles and the effect of nozzle aspect ratio and pressure ratio on the structure are brought out clearly in the present study. The mechanism governing the spreading and the axis switching characteristics are also brought out. Thus the present experimental and computational investigations give a comprehensive understanding of the mean flow structure of the underexpanded jets issuing from elliptical nozzles. Further studies are required to understand the other aspects of the elliptical jets as well as other three-dimensional jets. Some of these studies are identified for future work.
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2

Rajakuperan, E. "Experimental And Computational Investigations Of Underexpanded Jets From Elliptical Sonic Nozzles." Thesis, Indian Institute of Science, 1994. http://hdl.handle.net/2005/158.

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Abstract:
Three dimensional nozzles and jet flows have attracted the attention of many researchers due to their potential application to many practical devices. Rectangular nozzles are considered for short/vertical take off and landing aircrafts for achieving powered lift. Axisymmetric nozzles with lobes, tabs or slots and elliptical nozzles are considered for noise reduction in aircrafts and mixing augmentation in airbreathing rockets. Interaction of supersonic jets with solid surface, as in the case of retro and ullage rockets in launch vehicles and interaction of multiple jets as in the case of launch vehicles with multiple booster rockets/multiple nozzle engines are of practical importance. Design of rockets and aircrafts employing these nozzles needs the understanding of the structure and behaviour of the complex three dimensional supersonic jets issuing from these nozzles. The problem is so complex that different investigators have addressed only some specific aspects of the problem and there is much more to be done to fully understand these flows. For example, in the case of rectangular nozzle with semi circular ends (known as elliptical nozzle), the investigations have been limited to a single nozzle of aspect ratio 3,0 and pressure ratio (ratio of the total pressure to ambient pressure) 3.0. Further, the measurements were made in the far field subsonic region beyond a distance of 20 times the equivalent nozzle radius (RJ. For the present study, the elliptical sonic nozzle of the type mentioned above was chosen, as it offered simplicity for manufacturing and carrying out computations, but has all the complex features associated with the three dimensional jets. A systematic study to understand the mean flow structure and the effect of important governing parameters like ratio and pressure ratio on the flow development process of the jet issuing from Navier-Stokes equations. The experimental study revealed many interesting flow features. It was found that the Underexpanded jet issuing from elliptical sonic nozzle spreads rapidly in the minor axis plane while it maintains almost constant width or contracts in the major axis plane. However, the gross spreading of this jet is much higher compared to the axisymmetric jet. The higher spreading rates experienced in the minor axis plane compared to the major axis plane of this 'et, results in the jet width in the minor axis plane to become higher than that in the major axis plane. The longitudinal location, where this occurs is called the axis switching location. This kind of axis switching phenomenon is known to exist for subsonic elliptical jets. However, for the present supersonic jets, the axis switching locations are much closer to the nozzle exit compared to the subsonic cases reported. It was further found that this location strongly depends on the pressure and aspect ratios. A critical pressure ratio was found to exist for each nozzle at which the axis switching location is the farthest. Above the critical pressure ratio, the axis switching location was observed to move upstream with the increase in the pressure ratio and is controlled by the complex interactions of shock and expansion waves near the nozzle exit. Below the critical pressure ratio, the axis switching location moves upstream with the decrease in pressure ratio and is controlled by some kind of instability in the minor axis plane. The shock structure present in the underexpanded jet from an elliptical nozzle was also observed to depend on both pressure and aspect ratios. For some aspect ratios and pressure ratios, the shock pattern observed in both the major and minor axis planes are similar to that of an axisymmetric jet, where the incident barrel shock and the Mach reflection (from the edges of the Mach disk) are present. But for all other cases, this shock continues to be seen only in the major axis plane. Whereas, in the minor axis plane, the incident shock is absent in the shock pattern. Detailed measurement in the jet cross sectional planes, for the case of aspect ratio 2.0 nozzle, shows that the cross sectional shape changes along the length and it becomes almost a circle at the axis switching location. Further downstream, the jet spreads rapidly in the minor axis plane whereas no significant change in the width of the jet in the major axis plane is observed. Far downstream, the jet boundary appears like a distorted ellipse with its major and minor dimensions lying respectively in the minor and major axis planes of the nozzle. The elongated shape of the jet cross sections at locations downstream of the axis switching point gives the impression that the entire flow in the major axis plane is turned towards the minor axis plane. This effect appears to be predominant at high pressure ratios. The computed near field shock structure in the planes of symmetry, pitot pressure distributions, cross sectional shape of the jet and the spreading pattern agree very well with the experimental results. In addition to this, the present computational method gives the detailed near field flow structure including the azimuthal extent of the incident shock, cross flow details and distributions of flow variables. It is shown that the present inviscid methodology can also predict the axis switching point accurately if it occurs before the formation of the Mach disk and it demonstrates that the jet growth phenomenon in the near field, atleast, is mainly controlled by the inviscid flow process. The computed results have shown that changes in the jet cross sectional shape in the near field is caused mainly by the interaction of compression and expansion waves with each other and with the constant pressure boundary. The inviscid method seems to be able to capture the complicated secondary cross flow structure (indicating presence of longitudinal vortices) of the elliptical jet. The complex mean flow structure in the near field region of the jet issuing from elliptical nozzles and the effect of nozzle aspect ratio and pressure ratio on the structure are brought out clearly in the present study. The mechanism governing the spreading and the axis switching characteristics are also brought out. Thus the present experimental and computational investigations give a comprehensive understanding of the mean flow structure of the underexpanded jets issuing from elliptical nozzles. Further studies are required to understand the other aspects of the elliptical jets as well as other three-dimensional jets. Some of these studies are identified for future work.
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3

Liverani, Luca. "Cavitation in Real-Size Diesel Injector Nozzles." Thesis, City University London, 2010. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.525149.

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4

Marrion, Maynard. "Separation control in over-expanded supersonic nozzles." Thesis, University of Oxford, 2008. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.490110.

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Needle-free drug and vaccine delivery devices have been developed by the Department of Engineering Science at The University of Oxford in collaboration with PowderJect Pharmaceuticals plc. In them, micro-particles of pharmaceuticai agent are accelerated, by a supersonic flow of gas in a nozzle, to velocities sufficient for them to penetrate the outer layers of the skin. If the gas flow is over-expanded relative to the atmosphere to which it discharges, shock waves form inside the nozzle, which cause the flow to separate from the wall. The resulting gas-particle flow field is highly non-uniform, leading to suboptimal drug or vaccine delivery and even damage to the target skin.
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5

Fasci, Giuseppe Carmine. "CFD modelling of Retention Aids Dosage Nozzles." Thesis, KTH, Mekanik, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-98660.

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The objective of this project is to design, using computational fluid dynamics (CFD), a set of retention aid dosage nozzles that minimize shear levels during their operation. This includes the effect of dosage nozzle size, contour and dosage velocity - absolute and relative to the stock flow. As a starting point, the three different dosage nozzles currently implemented on the Innventia FEX paper-machine have been studied using CFD. Problem areas, defined as regions of high viscous and/or turbulent shear, with these designs should be identified, and solutions to their improvement have been realized. The computational models considered here include non Newtonian models of the retention aid solution, as well as turbulent modeling of the stock flow. Novel configurations have been implemented which attempt to minimize the strain rate and shear stress during dosage and at the same time improve the mixing quality of the retention aid polymers. While the velocity of the side jet is determined to be the main cause of high strain rates and shear stresses, a good mixing can be reached by varying the position of the nozzles and the diameter penetrating the stock flow. The best compromise of mixing and shear stress has been reached with a triple side-wall nozzles configuration.
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6

Izola, Dawson Tadeu. "Investigação da indução de engasgamento em tubeira DeLAVAL para motor-foguete por intermédio do prolongamento da garganta." Universidade de São Paulo, 2013. http://www.teses.usp.br/teses/disponiveis/18/18148/tde-16022018-143941/.

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A condição ótima de funcionamento de uma tubeira em um motor foguete com escoamento isentrópico, implica que a velocidade na garganta (seção de menor área) seja equivalente à velocidade do som local, condição de Mach 1 e bocal engasgado. Pode-se alcançar essa condição reduzindo a área da seção do escoamento até a área crítica, velocidade sônica. Após a garganta acontece a expansão e se alcança velocidades supersônicas no divergente. Para manter a condição de Mach 1 na garganta em motores foguetes, trabalha-se com pressões superiores à necessária para se engasgar o bocal. Isto ocorre porque tenta-se compensar instabilidades ou variações de volumes produzidos na combustão ou queima. Usando uma pressão de trabalho maior, impõe-se que a condição de Mach 1 fique mantida durante toda a queima do combustível, isso implica em usar tubos mais resistentes à pressão e maior massa do tubo-motor. Observou-se experimentalmente que em algumas situações construtivas se podem modificar a pressão e temperatura necessárias para engasgar o bocal aumentando o comprimento da garganta. O comprimento do estrangulamento pode estabelecer uma condição para formação e evolução da camada limite e esta condição restringir a área nominal, modificando o regime do escoamento. Um equipamento especialmente desenvolvido para esse ensaio compara resultados de cinco modelos de motores, divididos em dois grupos, cada grupo com áreas de entrada, garganta e saída iguais, porém com comprimentos diferentes de garganta. Em análise experimental, observou-se que a pressão de trabalho e a temperatura são influenciadas pelo comprimento da garganta, interferindo na relação entre as pressões internas e de garganta e apresentando condições de engasgamento mensuráveis. Essas medidas foram conduzidas no presente estudo de doutorado.
The optimum operational condition of a rocket motor nozzle with isentropic flow implies that the velocity at the throat (the section with smallest area) is equivalent to the speed of the local sound. This speed is also called Mach 1 and it is said that at this condition the nozzle is choking. One can achieve this condition by reducing the cross-sectional area of the flow to the critical area resulting in a sonic speed. Beyond the nozzle throat, in the divergent section of the motor, flow expansion occurs and reaches supersonic speeds. To maintain the condition of Mach 1 at the throat, higher pressures than the one necessary to choke the nozzle are applied. This practice is done in order to compensate for jitter or variations of volumes produced in the combustion process. Using a higher operating pressure guarantees that a Mach 1 speed is maintained throughout the combustion process. Consequently, due to this higher operating pressure, more resistant tubes are needed to withstand this higher pressure and an increase in the motor weight is inevitable. It was observed experimentally that some constructional modifications of the motor can alter the pressure and temperature required for choking. This was noted with increasing the bottleneck length of the nozzle throat which was able to establish a condition for the formation and evolution of the boundary layer, restricting the nominal area and thus modifying the flow regime. In this study, the results of five engine models are compared using a specially designed equipment. The rockets were divided into two groups, each with equal inlet, throat, and exit areas, but having different throat lengths. In experimental analysis, it was observed that the working pressure and temperature are influenced by the length of the throat, interfering in the relationship between the internal pressures and throat presenting measurable choking conditions which were conducted in this doctorate thesis study.
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7

Thacker, John Edward. "Design of medium pressure nozzles for cooling towers." Thesis, Stellenbosch : Stellenbosch University, 1997. http://hdl.handle.net/10019.1/55448.

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Thesis (MScEng)--Stellenbosch University, 1997.
One copy microfiche.
ENGLISH ABSTRACT: This project concerns the investigation of parameters controlling the behaviour of full-cone spray nozzles of the type used in cooling towers. In the present study large medium pressure hollow and full cone nozzles were investigated. A literature survey provided insight into the relationships between the nozzle dimensions and their spray characteristics, while equations found in the literature were used to correlate the experimental data. It was found that the spray cone angle of hollow cone nozzles could be manipulated by using rounded orifice outlets and this finding lead to the development of a uniquely profiled outlet that actually produces a square spray pattern. More experimental work was done to determine the relationship between the central jet of a full-cone nozzle and the other major nozzle dimensions. These results were then correlated and formulated into a set of guidelines for designing full-cone nozzles.
Digitized at 300 dpi Colour PDF format (OCR), using ,KODAK i 1220 PLUS scanner. Digitised, Ricardo Davids on request from Corinna 01 October 2014
AFRIKAANSE OPSOMMING: Hierdie projek behels 'n studie van belangrike parameters in volkegel sproeimondstukke soos gebruik in koeltorings. In die huidige studie word groot mediumdruk holkegel en volkegel sproeimondstukke ondersoek. 'n Literatuurstudie het die nodige insig verskaf omtrent die verwantskap tussen mondstuk dimensies en hul spuitkarakteristieke, terwyl vergelykings uit die literatuur gebruik is om die eksperimentele data te korreleer. Dit was gevind dat die sproeir kegelhoek van die holkegelmondstuk verander kon word deur gebruik te maak van geronde uitlate. Afleidings wat gemaak is het gely tot die ontwikkeling van 'n unieke geprofielde uitlaat wat 'n vierkantige sproeipatroon gelewer het. Bykomstige eksperimentele werk is gedoen om die verwantskap tussen die sentralestraal van 'n volkegelmondstuk en die ander hoof mondstukdimensies te bepaal. Die reultate is verwerk om riglyne vir die ontwerp van vierkantige patroon volkegel mondstukke daar te stel.
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Fry, Richard N. "Dense gas effects in a converging-diverging nozzle." Thesis, This resource online, 1992. http://scholar.lib.vt.edu/theses/available/etd-12232009-020448/.

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Newbold, Gregory. "Mixing and combustion in precessing jet flows /." Title page, contents and abstract only, 1998. http://web4.library.adelaide.edu.au/theses/09PH/09phn534.pdf.

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Nichols, James Franklin. "Two-dimensional analysis of turbine blades and nozzles." Thesis, Georgia Institute of Technology, 2001. http://hdl.handle.net/1853/17673.

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Books on the topic "Nozzles"

1

Hamed, A. High speed nozzles task: Final report. [Cincinnati, Ohio?]: University of Cincinnati, 1995.

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Smith, Tamara A. Comparison of theoretical and experimental thrust performance of a 1030:1 area ratio rocket nozzle at a chamber pressure of 2413 kN/m(2) (350 psia). Cleveland, Ohio: Lewis Research Center, 1987.

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G, Keith Theo, and United States. National Aeronautics and Space Administration., eds. Analysis and design of optimized truncated scarfed nozzles subject to external flow effects. [Washington, D.C.]: National Aeronautics and Space Administration, 1990.

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Milton, Lamb, and United States. National Aeronautics and Space Administration. Scientific and Technical Information Division., eds. Aeropropulsive characteristics of isolated combined turbojet/ramjet nozzles at Mach numbers from 0 to 1.20. [Washington, D.C.]: National Aeronautics and Space Administration, Scientific and Technical Information Division, 1988.

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H, Dieck Ronald, Chuang Isaac, and United States. National Aeronautics and Space Administration., eds. A detailed description of the uncertainty analysis for high area ratio rocket nozzle tests at the NASA Lewis Research Center. [Washington, D.C.?]: National Aeronautics and Space Administration, 1987.

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Kacynski, Kenneth J. Experimental evaluation of heat transfer on a 1030:1 area ratio rocket nozzle. Cleveland, Ohio: Lewis Research Center, 1987.

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M, Kazaroff John, Pavli Albert J, and United States. National Aeronautics and Space Administration. Scientific and Technical Information Program., eds. Experimental performance of a high-area-ratio rocket nozzle at high combustion chamber pressure. [Washington, D.C.]: National Aeronautics and Space Administration, Office of Management, Scientific and Technical Information Program, 1996.

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M, Kazaroff John, Pavli Albert J, and United States. National Aeronautics and Space Administration. Scientific and Technical Information Program., eds. Experimental performance of a high-area-ratio rocket nozzle at high combustion chamber pressure. [Washington, D.C.]: National Aeronautics and Space Administration, Office of Management, Scientific and Technical Information Program, 1996.

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M, Kazaroff John, Pavli Albert J, and United States. National Aeronautics and Space Administration. Scientific and Technical Information Program, eds. Experimental performance of a high-area-ratio rocket nozzle at high combustion chamber pressure. [Washington, D.C.]: National Aeronautics and Space Administration, Office of Management, Scientific and Technical Information Program, 1996.

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Carlson, John R. Two-dimensional converging-diverging rippled nozzles at transonic speeds. Hampton, Va: Langley Research Center, 1994.

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Book chapters on the topic "Nozzles"

1

Schaschek, Karl. "Procedure for Identifying Defect Inkjet Nozzles." In Technologien für die intelligente Automation, 317–29. Berlin, Heidelberg: Springer Berlin Heidelberg, 2022. http://dx.doi.org/10.1007/978-3-662-64283-2_23.

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AbstractIn graphic and industrial printing applications inkjet technologies are gaining attention and market coverage. Beside some key success factors as scalability there is an inherent difficulty of temporally or permanent defective/non operating nozzles. These non working nozzle have a severe impact on printed quality. Several approaches are known to reduce these artefacts. One is to use multi-pass printing, sometimes in combination with the use of defect nozzle information. Another is to detect these nozzles direct or indirect and use for example so called reserve nozzles. A predecessor thereof is the detection of pen lines (Beauchamp et al (1992) Hewlett-Packard J 12:35–41). In multi-nozzle systems individual or groups of nozzles are addressed to fire using a matrix scheme. This method reduces the number of used address lines.Here an automated working scheme is sketched to firstly identify defect nozzles using a sample print by means of a dedicated pattern. A digital picture taken by scan or camera is the basis of an image analysis procedure afterwards. Secondly it is shown that, once the matrix configuration is known, possible defects of the address lines may be identified too. Finally a pattern dedicated to a specific print head is introduced to check the later fact visually.
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Omer, K., and N. Ashgriz. "Spray Nozzles." In Handbook of Atomization and Sprays, 497–579. Boston, MA: Springer US, 2010. http://dx.doi.org/10.1007/978-1-4419-7264-4_24.

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Kügler, Thomas. "Injection nozzles." In Diesel Engine Management, 152–61. Wiesbaden: Springer Fachmedien Wiesbaden, 2014. http://dx.doi.org/10.1007/978-3-658-03981-3_14.

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Pirumov, Ul’yan G., and Gennadi S. Roslyakov. "Nozzles of Jet Engines." In Gas Flow in Nozzles, 143–98. Berlin, Heidelberg: Springer Berlin Heidelberg, 1986. http://dx.doi.org/10.1007/978-3-642-86790-3_5.

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Pirumov, Ul’yan G., and Gennadi S. Roslyakov. "Introduction." In Gas Flow in Nozzles, 1–5. Berlin, Heidelberg: Springer Berlin Heidelberg, 1986. http://dx.doi.org/10.1007/978-3-642-86790-3_1.

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Pirumov, Ul’yan G., and Gennadi S. Roslyakov. "General Theory of Nozzle Gas Flows." In Gas Flow in Nozzles, 6–64. Berlin, Heidelberg: Springer Berlin Heidelberg, 1986. http://dx.doi.org/10.1007/978-3-642-86790-3_2.

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Pirumov, Ul’yan G., and Gennadi S. Roslyakov. "Numerical Methods of Studying Nozzle Gas Flows." In Gas Flow in Nozzles, 65–109. Berlin, Heidelberg: Springer Berlin Heidelberg, 1986. http://dx.doi.org/10.1007/978-3-642-86790-3_3.

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Pirumov, Ul’yan G., and Gennadi S. Roslyakov. "Asymptotic Methods in the Theory of Nozzles." In Gas Flow in Nozzles, 110–42. Berlin, Heidelberg: Springer Berlin Heidelberg, 1986. http://dx.doi.org/10.1007/978-3-642-86790-3_4.

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Pirumov, Ul’yan G., and Gennadi S. Roslyakov. "Flows with Physico-Chemical Transformations." In Gas Flow in Nozzles, 199–317. Berlin, Heidelberg: Springer Berlin Heidelberg, 1986. http://dx.doi.org/10.1007/978-3-642-86790-3_6.

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Pirumov, Ul’yan G., and Gennadi S. Roslyakov. "Special Nozzles, Three-Dimensional Flows, Viscosity Effect." In Gas Flow in Nozzles, 318–403. Berlin, Heidelberg: Springer Berlin Heidelberg, 1986. http://dx.doi.org/10.1007/978-3-642-86790-3_7.

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Conference papers on the topic "Nozzles"

1

Hagemann, G., H. Immich, and M. Terhardt. "Flow phenomena in advanced rocket nozzles - The plug nozzle." In 34th AIAA/ASME/SAE/ASEE Joint Propulsion Conference and Exhibit. Reston, Virigina: American Institute of Aeronautics and Astronautics, 1998. http://dx.doi.org/10.2514/6.1998-3522.

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Watanabe, Masaru, Takeshi Ueda, Koji Okimura, Kazuhiro Wakabayashi, Takashi Akaba, Kazuhiko Kamo, Takahiro Ohta, Shohei Nakama, and Hiroyuki Kobayashi. "Application of L-SIP to Pressurizer Nozzles." In ASME 2011 Pressure Vessels and Piping Conference. ASMEDC, 2011. http://dx.doi.org/10.1115/pvp2011-57496.

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It has long been known that the most effective in a countermeasure for stress corrosion cracking in pipe and nozzle welds is by reducing the residual stress in the portion of the weld exposed to the corrosive environment. An irradiated laser stress improvement process (L-SIP) was introduced as a method to improve residual stress inside steel pipes and nozzles. L-SIP has been applied to the pressurizer nozzles in actual plant, Tsuruga unit 2 Japan, for the first time in the world. The nozzles to which this process was applied are the surge nozzle (September 2007), safety nozzles, relief nozzle and spray line nozzle (April 2010). L-SIP can be applied without inner surface cooling because the high power laser beam can generate the sufficient temperature difference without such cooling. Where necessary to achieve optimum temperarure difference, water cooling may also be applied at the inner surface. At Tsuruga unit 2, L-SIP was successfully applied to the spray line nozzle in air-cooling mode, and the surge nozzles, 3 safety nozzles and relief nozzle in water-cooling mode.
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Soman, Abhimanyu, and Simone Colantoni. "Design Optimization of Integrated Anti-Rotation Feature for Power Turbine Nozzles." In ASME Turbo Expo 2022: Turbomachinery Technical Conference and Exposition. American Society of Mechanical Engineers, 2022. http://dx.doi.org/10.1115/gt2022-78254.

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Abstract Gas turbine nozzles are static components that are meant to turn and accelerate high temperature, high pressure, and low-velocity flue gas into the downstream turbine row of buckets. During gas turbine operation, nozzles are subjected to high-pressure load due to the expansion of flue gases, in axial and tangential directions. This creates a tendency for nozzle movement in tangential direction which has potential to create flow disturbance and intersegment gap opening. To prevent this movement, it should be held in tangential direction firmly by introducing an anti-rotation feature. A slot is introduced in the nozzle outer sidewall and a pin connected with casing in such a way that the nozzle’s tangential movement is restrained. As the nozzle’ s outer sidewall experiences high thermal gradients in the operating condition, it induces high stress at the nozzle anti-rotation feature. There are many possible design options available to mitigate this challenge. In the present work, anti-rotation feature is integrated with the nozzle’s outer sidewall and a matching slot is provided in the casing. A detailed study is performed to optimize this anti-rotation feature to reduce high thermal-mechanical stress and thereby improve reliability. The low cycle fatigue life is one of the vital requirements in improving reliability. The low cycle fatigue life of the optimized anti-rotation feature is validated using the finite element analysis. This paper describes the process step details in optimizing the anti-rotation feature.
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Moreno, Gilberto, Seung M. You, and Erlendur Steinthorsson. "Spray Cooling Performance of Single and Multi-Jet Spray Nozzles Using Subcooled FC-72." In ASME/JSME 2007 Thermal Engineering Heat Transfer Summer Conference collocated with the ASME 2007 InterPACK Conference. ASMEDC, 2007. http://dx.doi.org/10.1115/ht2007-32429.

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In this study experiments were performed to evaluate the spray cooling performance of three different spray nozzles using gassy-subcooled (∼Tsub = 31°C) FC-72 as the working fluid. The three different nozzles tested can be characterized as a single hollow cone spray nozzle (Nozzle A), 2×2 jet array spray nozzle (Nozzle B) and a 4×4 jet array spray nozzle (Nozzle C). For all tests, a 10×10 mm polished (600 grit) copper surface was utilized as the heater and tests were carried out at near atmospheric pressure conditions. All three nozzles were tested at various flow rates and nozzle-to-heater distances and the results were compared. Results show that changing the nozzle-to-heater distance affects heat transfer rates more than critical heat flux (CHF). The spray boiling curves for all three nozzles were similar with Nozzle C, for some cases, demonstrating the highest heat transfer rates. The disparity in CHF values between the various nozzles was more apparent. Compared at an equivalent flow rate, Nozzle C consistently produced CHF values which were higher than those of the other nozzles. Some common trends observed for all nozzles are, increasing flow rate increases heat transfer rates and critical heat flux (CHF) but decreases nozzle efficiency.
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Clarke, Edward, and Robert Frith. "The Effect of Nozzles and Nozzle Loadings on Shell Buckling." In ASME 2015 Pressure Vessels and Piping Conference. American Society of Mechanical Engineers, 2015. http://dx.doi.org/10.1115/pvp2015-45090.

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This paper investigates the effect of nozzles and nozzle loadings on the overall buckling capacity of a vessel subject to external pressure designed to ASME VIII Div 1. ASME VIII Div 1 provides a well-established design-by-rule (DBR) approach for vessels subject to external pressure, but this takes no consideration for the presence of openings or nozzles. There are empirical rules regarding nozzle reinforcement for external pressure, but these do not directly consider the buckling capacity of the overall vessel. This paper therefore assesses the impact of nozzles on the buckling capacity of a cylindrical shell, where the nozzle is reinforced as per code requirements. The effect of reduced reinforcement is also analyzed. Subsequently the effect of nozzle loads is also assessed. Nozzles are loaded with ‘allowable’ loads, determined using finite element analysis in accordance with industry practice and code principles. The buckling capacities are assessed using ASME VIII Div 2 Part 5 methods, using a parametric study with over 500 models. Variables considered are vessel diameter, vessel length, nozzle diameter, and both integral and pad-reinforced nozzles are used.
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Kwong, W. Y., and A. M. Steinberg. "Blowoff and Reattachment Dynamics of a Linear Multi-Nozzle Combustor." In ASME Turbo Expo 2018: Turbomachinery Technical Conference and Exposition. American Society of Mechanical Engineers, 2018. http://dx.doi.org/10.1115/gt2018-75647.

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This paper describes the coupled flow and flame dynamics during blowoff and reattachment events in a combustor consisting of a linear array of five interacting nozzles using 10 kHz repetition-rate OH planar laser induced fluorescence and stereoscopic particle image velocimetry. Steady operating conditions were studied at which the three central flames randomly blew-off and subsequently reattached to the bluff-bodies. Transition of the flame from one nozzle was rapidly followed by transition of the other nozzles, indicating cross-nozzle coupling. Blow-off transitions were preferentially initiated in one of the off-center nozzles, with the transition of subsequent nozzles occurring in a random order. Similarly, the center nozzle tended to be the last nozzle to reattach. The blowoff process of any individual nozzle was similar to that for a single bluff-body stabilized flame, though with cross-flame interactions providing additional means of re-stabilizing a partially extinguished flame. Subsequent to blowoff of the first nozzle, the other nozzles underwent similar blowoff processes. Flame reattachment was initiated by entrainment of a burning pocket into a recirculation zone, followed by transport to the bluff-body; the other nozzles subsequently underwent similar reattachment processes. Several forms of cross-nozzle interaction that can promote or prevent transition are identified. Furthermore, the velocity measurements indicated that blowoff or reattachment of the first nozzle during a multi-nozzle transition causes significant changes to the flow fields of the other nozzles. It is proposed that a single nozzle transition redistributes the flow to the other nozzles in a manner that promotes their transition.
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Deng, Jianxin. "Sand Erosion Performance of Gradient Ceramic Nozzles by Abrasive Air-Jets." In ASME 2006 International Manufacturing Science and Engineering Conference. ASMEDC, 2006. http://dx.doi.org/10.1115/msec2006-21057.

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A SiC/(W,Ti)C ceramic nozzle with gradient structures was produced by hot pressing. The purpose is to reduce the tensile stress at the entry region of the nozzle in abrasive air-jet. The sand erosion performance of this kind gradient ceramic nozzle caused by abrasive particle impact was investigated by abrasive air-jets in comparison with the common one. Results showed that the gradient ceramic nozzles exhibited an apparent increase in erosion wear resistance over the common ceramic nozzles. The mechanism responsible was explained as the formation of compressive residual stresses in nozzle entry region in fabricating process of the gradient ceramic nozzles, which may partially counteract the tensile stresses resulting from external loadings. It is indicated that gradient structures in ceramic nozzles is an effective way to improve the erosion wear resistance of common ceramic nozzles.
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Tran, Si Bui Quang, Doyoung Byun, Vu Dat Nguyen, Myoung Jong Yu, and Kyun Ho Lee. "Fabrication and Test of Polymer-Based Electrospray Device." In ASME 2008 International Mechanical Engineering Congress and Exposition. ASMEDC, 2008. http://dx.doi.org/10.1115/imece2008-68203.

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In this paper, interference effect between multi-nozzles has been experimentally investigated for an electrospray device. Array of nozzles is either prepared by electrically conductive stainless steel capillaries and by electrically dielectric nozzle array fabricated using polymer material. The result shows that polymer-based device may reduce or avoid the interference effect when the spacing distance between nozzles is optimized. For a conductive electrospray array, the end effect, which is able to deflect conejets through the outer nozzles of the array due to asymmetric electric field and repulsive forces between adjacent conductive nozzles and the menisi, can be eliminated by using two dry nozzles mounted at the boundary. However, for a polymer-based device, the end effect can be avoided without using extra dry nozzles. In order to eliminate this end effect, a novel ten-nozzle Polymethyl Methacrylate (PMMA)-based electrospray, with inner and outer diameters of 300μm and 500μm, respectively, has been successfully fabricated and evaluated. The performce of the multi-nozzle array device is analysed by measuring the current of the charged droplets through a novel ten nozzles of the polymer-based electrospray device.
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Dolan, Brian, Rodrigo Villalva Gomez, and Ephraim Gutmark. "Optical Measurements of Interacting Lean Direct Injection Fuel Nozzles With Varying Spacing." In ASME Turbo Expo 2015: Turbine Technical Conference and Exposition. American Society of Mechanical Engineers, 2015. http://dx.doi.org/10.1115/gt2015-43706.

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Particle image velocimetry and OH planar laser induced fluorescence are used to examine the flow and flame structure resulting from two adjacent fuel/air nozzles. The distance between nozzles is varied from 1.1 to 2.72 nozzle diameters to change the degree of interaction between the nozzles. Non-reacting PIV shows a flowfield which is nearly symmetric between nozzles for all four spacings. For all but the widest spacing, there exist differences in the flow structures between the inner and outer sides of the nozzles. Less distance between the nozzles results in more rapid merging of the shear layers and higher axial velocities between the nozzles. At a spacing of 1.89 nozzle diameters, the shear layers toward the adjacent nozzle are intermittently pulled into the center of the combustor, resulting in a wider and lower velocity average flow between nozzles compared to the other cases. When a flame is added, the flowfields become much more asymmetric, both between nozzles and between the shear layers toward and away from the interacting nozzle. The outer shear layers, away from the other nozzle, are pushed to the domeplate by the expanding recirculation region. With a higher airflow, this behavior is negated. At the two further spacings, the shear layers toward the adjacent nozzle also become different between swirlers. The flow from the nozzle located on the right stays near the domeplate and joins the shear layer from the left nozzle near the nozzle lip and becomes a strong and penetrating jet at an angle to the axial coordinate. OH PLIF imaging shows that the flame fronts are generally located in the shear layer between the incoming reactants and the recirculating combustion products. This includes cases where the flow is highly asymmetric and stays close to the domeplate or penetrates deep into the combustor. So there is no evidence that the addition of an adjacent nozzle has an effect on the local flow/flame interaction. However, it is also clear that the presence of interacting swirling flows with combustion can lead to very dramatic changes to the global flow behavior relative to a single nozzle experiment.
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Shitolé, Bhaskar Dattatray. "Allowable Piping Imposed Nozzle Loads on Pumps of Large Diameter Nozzles." In ASME 2016 Pressure Vessels and Piping Conference. American Society of Mechanical Engineers, 2016. http://dx.doi.org/10.1115/pvp2016-64034.

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Piping imposed loads are external forces and moments acting on pump suction and discharge nozzles. API 610 2010, 11th Edition, Table 5, provides a basis for nozzle sizes DN 50 to DN 400 for external forces and moments on pump nozzles. There is a frequent need in the industry for pumps of larger volumetric flow rates to have nozzle sizes larger than DN 400. The fast-track requirements of a project schedule needs a realistic and quick methodology for the pump manufacturer and piping stress engineer to have a basis for calculating external forces and moments imposed on nozzle sizes larger than DN 400. This paper provides a methodology for determining forces and moments on pump nozzle sizes larger than DN 400. The methodology is based on the practical aspect of the most important property of pipe, which influences the quantity of force and moment it can impose.
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Reports on the topic "Nozzles"

1

Kirkpatrick, Mitchell, and Willson. L51953 CFD Modeling of Gas Flow and Mixing in a Two-Stroke Natural Gas Engine. Chantilly, Virginia: Pipeline Research Council International, Inc. (PRCI), September 2002. http://dx.doi.org/10.55274/r0010912.

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The objective of this project is to examine the effect of the injection pressure on the subsequent mixing in the cylinder. We examine the injection of natural gas from two types of poppet valves, shrouded and unshrouded valves and assess the ability of a commercial CFD code to compute the velocity and pressure profiles in high pressure gas flow from simple sonic nozzles. A sonic nozzle is a convergent or straight nozzle with an exit Mach number equal to one. The main parameters determining the type of the flow exiting from a sonic nozzle are the ratio of the injection pressure to the cylinder pressure and the nozzle geometry. As the injection pressure increases, a point is reached for convergent nozzles where the exit velocity reaches the speed of sound. This pressureratio is the critical pressure ratio for the nozzle. For an ideal gas with a specific heat ratio of 1.35, the critical pressure ratio is 1.86. At higher pressure ratios, the exit velocity remains sonic, but the exit pressure is greater than ambient, thus substantial gas expansion from the exit pressure to the cylinder pressure is required downstream of the nozzle. This type of nozzle outflow is defined as an underexpanded jet.
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Olsen, Daniel, and Kris Quillen. GRI-05-0074 Engine Testing of Optimized Nozzles for High Pressure Fuel Injection. Chantilly, Virginia: Pipeline Research Council International, Inc. (PRCI), March 2005. http://dx.doi.org/10.55274/r0011762.

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High-pressure fuel injection has become an important retrofit technology for lowering emission and fuel consumption in large bore natural gas engines. As emissions regulations become more stringent, the need for further reductions in pollutant emissions and fuel consumption is apparent. One aspect of high-pressure fuel injection where there is still room for improvement is the nozzle. The nozzle can both redirect and accelerate the fuel jet as it enters the cylinder. In this work, various new supersonic nozzle designs are experimentally evaluated. Experimental results for two different fuel injection systems are presented. The two systems are differentiated by the supply pressure. One operates at 275 PSIG and the other at 500 PSIG. Experimental evaluation is on a Cooper-Bessemer GMV-4TF large bore natural gas engine. Nozzle comparisons are made against stock Hoerbiger nozzles.
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Madrzykowski, Daniel, and Nicholas Dow. Residential Flashover Prevention with Reduced Water Flow: Phase 1. UL Firefighter Safety Research Institute, April 2020. http://dx.doi.org/10.54206/102376/jegf7178.

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This study was designed to be an initial step to investigate the potential of low flow nozzles as part of a retrofit flashover prevention system in residential homes with limited water supplies. Not all homes have water supplies that can meet the needs of a residential sprinkler system. Current alter- natives, such as including a supplemental tank and pump, increase the cost of the system. These homes could benefit from an effective fire safety system with lower water supply requirements. The experiments in this study were conducted in a steel test structure which consisted of a fire room attached to a hallway in an L-shaped configuration. Three types of experiments were conducted to evaluate nozzles at different flow rates and under different fire conditions. The performance of the nozzles was compared to the performance of a commercially available residential sprinkler. The first set of experiments measured the distribution of the water spray from each of the nozzles and the sprinkler. The water spray measurements were made without the presence of a fire. The other two sets of experiments were fire experiments. The first set of fire experiments were designed to measure the ability of a water spray to cool a hot gas layer generated by a gas burner fire. The fire source was a propane burner which provided a steady and repeatable flow of heat into the test structure. Two water spray locations were examined, in the fire room and in the middle of the hallway. In each position, the burner was shielded from the water spray. The results showed that for equivalent conditions, the nozzle provided greater gas cooling than the sprinkler. The tests were conducted with a fire size of approximately 110 kW, and water flow rates in the range of 11 lpm (3 gpm) and 19 lpm (5 gpm). The second set of fire experiments used an upholstered sofa as the initial source of the fire with the water spray located in the same room. As a result of the compartment size and water spray distribution, the nozzle flowing water at 23 lpm (6 gpm) provided more effective suppression of the fire than the sprinkler flowing 34 lpm (9 gpm) did. The nozzle was similarly effective with the ignition location moved 1.0 m (3.2 ft) further away. However, the nozzle failed to suppress the fire with a reduced water flow rate of 11 lpm (3 gpm). The results of this limited study demonstrate the potential of low flow nozzles, directly flowing water on to the fuel surface, with the goal of preventing flashover. Additional research is needed to examine larger room sizes, fully furnished rooms, and shielded fires to determine the feasibility of a reduced water flow flashover prevention system.
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Grisso, Robert, Shawn D. Askew, and David McCall. Nozzles: Selection and Sizing. Blacksburg, VA: Virginia Cooperative Extension, August 2019. http://dx.doi.org/10.21061/442-032_bse-262p.

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Jeffrey D. Smith, Kent D. Peaslee, David C. Van Aken. Steelmaking Nozzles That Resist Clogging. Office of Scientific and Technical Information (OSTI), July 2006. http://dx.doi.org/10.2172/899850.

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Pan, Yong-Le, John Bowersett, Steven C. Hill, Ronald G. Pinnick, and Richard K. Chang. Nozzles for Focusing Aerosol Particles. Fort Belvoir, VA: Defense Technical Information Center, October 2009. http://dx.doi.org/10.21236/ada508533.

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Ahedo, Eduardo, and Mario Merino. Plasma Detachment Mechanisms in Propulsive Magnetic Nozzles. Fort Belvoir, VA: Defense Technical Information Center, March 2013. http://dx.doi.org/10.21236/ada582517.

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Gerwin, R. A., G. J. Marklin, A. G. Sgro, and A. H. Glasser. Characterization of Plasma Flow Through Magnetic Nozzles. Office of Scientific and Technical Information (OSTI), February 1990. http://dx.doi.org/10.2172/763033.

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9

Delvaux, John, and Joseph Weber. HIGH TEMPERATURE CMC NOZZLES FOR 65% EFFICIENCY. Office of Scientific and Technical Information (OSTI), December 2021. http://dx.doi.org/10.2172/1837448.

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10

Dow, Nick, and Daniel Madrzykowski. Residential Flashover Prevention with Reduced Water Flow: Phase 2. UL's Fire Safety Research Institute, November 2021. http://dx.doi.org/10.54206/102376/nuzj8120.

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Abstract:
The purpose of this study was to investigate the feasibility of a residential flashover prevention system with reduced water flow requirements relative to a residential sprinkler system designed to meet NFPA 13D requirements. The flashover prevention system would be designed for retrofit applications where water supplies are limited. In addition to examining the water spray’s impact on fire growth, this study utilized thermal tenability criteria as defined in UL 199, Standard for Automatic Sprinklers for Fire-Protection Service. The strategy investigated was to use full cone spray nozzles that would discharge water low in the fire room and directly onto burning surfaces of the contents in the room. Where as current sprinkler design discharges water in a manner that cools the hot gas layer, wets the walls and wets the surface of the contents in the fire room. A series of eight full-scale, compartment fire experiments with residential furnishings were conducted with low flow nozzles. While the 23 lpm (6 gpm) of water was the same between experiments, the discharge density or water flux around the area of ignition varied between 0.3 mm/min (0.008 gpm/ft2) and 1.8 mm/min (0.044 gpm/ft2). Three of the experiments prevented flashover. Five of the experiments resulted in the regrowth of the fire while the water was flowing. Regrowth of the fire led to untenable conditions, per UL 199 criteria, in the fire room. At approximately the same time as the untenability criteria were reached, the second sprinkler in the hallway activated. In a completed system, the activation of the second sprinkler would reduce the water flow to the fire room, which would potentially lead to flashover. The variations in the burning behavior of the sofa resulted in shielded fires which led to the loss of effectiveness of the reduced flow solid cone water sprays. As a result of these variations, a correlation between discharge density at the area of ignition and fire suppression performance could not be determined given the limited number of experiments. An additional experiment using an NFPA 13D sprinkler system, flowing 30 lpm (8 gpm), demonstrated more effective suppression than any of the experiments with a nozzle. The success of the sprinkler compared with the unreliable suppression performance of the lower flow nozzles supports the minimum discharge density requirements of 2 mm/min (0.05 gpm/ft2) from NFPA 13D. The low flow nozzle system tested in this study reliably delayed fire growth, but would not reliably prevent flashover.
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