The paper investigates the effect of the fabrication method, precision and surface roughness on atomization nozzle performance. A comprehensive review of the available knowledge on the topic is an ...integral part and an indispensable prerequisite of the study. It focuses on the requirements for atomizing nozzles and their production from the point of view of surface quality, dimensional and shape accuracy. The published results on the influence of surface quality and roughness on internal flow and atomizer performance are discussed. Available atomizer manufacturing techniques are reviewed with a focus on Rapid prototyping methods, accuracy and geometrical imperfections.
Classical Machining and two 3D printing techniques were applied to produce small pressure-swirl atomizers. They were fabricated in a number of versions. The machined nozzles featured several specific defects. Spray quality measurements of these atomizers, at selected operation regimes, were made on a cold test bench using PDA and mechanical patternation to evaluate discharge coefficient (CD), Sauter mean diameter, spray cone angle, nozzle efficiency (ηn), breakup length and liquid distribution in the spray.
The results show the important and systematic effects of surface quality and manufacturing imperfections on the atomizer characteristics. The exit orifice imperfections harm the circumferential uniformity and other spray characteristics. The effect becomes significant when the exit orifice shifted out of the nozzle axis by >2 % of the chamber diameter, and the orifice edge is chamfered by >20 % of the orifice length. The swirl chamber surface modified by scratches has a minor effect.
Replacement of machining with current commercial 3D printing techniques, namely Selective laser melting and PolyJet technique, is associated with increased surface roughness. It worsens spray quality, liquid distribution uniformity and ηn and increases the CD when relative surface roughness exceeds 0.007.
The result presentation using dimensionless criteria allows for generalisation of the outcomes to other atomizer types and scales.
•Machining and 3D printing were applied to produce a set of small swirl atomizers.•Surface quality and manufacturing imperfections strongly effect atomizer characteristics.•Exit orifice errors harm the circumferential uniformity and other spray characteristics.•3D printing instead of machining increases relative surface roughness, k.•The effect on spray quality, symmetry, and nozzle efficiency applies when k > 0.007.
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The appearance of errors leading to fracture of compressor and pump parts is investigated. A method is proposed for nondestructive monitoring of the manufacturing precision of flexible parts with ...surfaces of revolution at the ends. This approach to minimizing component fractures does not decrease the productivity.
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The manufacture of rolling tools of complex shape for the production of roofing sheets is considered. To ensure manufacturing precision in stepwise plunge grinding of the rollers, mean insertion ...parameters are selected.
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The production of small complex components by electric-discharge milling is studied by experimental methods. Means of optimizing numerical-control software so as to obtain the required shaping ...precision are proposed. The proposed systems and equipment permit the development and implementation of designs unattainable by other means.
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The article is devoted to the development of high-tech metal-working industry, as well as to the use of unmanned technology. We recommended measures to improve the accuracy and quality of ...manufacturing of complex and large workpieces weighing up to 100 tons. To date, the technical level of many economy sectors is largely determined by the level of the production means. Based on the engineering development there is an overall automation and mechanization of production and industry processes, construction, agriculture, transport and other industries. We analyzed forms of slide sections, of errors affecting the accuracy of the workpieces manufacturing. We made simulation of the cutting forces and sliders deformations. Solved measures increase manufacturing accuracy based on multi-purpose machine tool systems of VM series. We held the analysis of the dependence of cutting forces, a slider form on its strain in different types of processing. We obtained a graph of cutting force and precision manufacturing. We defined the optimal shape of the slider cross section to increase the rigidity and reduce the slide deformation in metal cutting
The bending sheet metal inevitably exist bending errors including angle error, linearity error and length error of sideline for reasons that the structure of press brake, the manufacturing precision ...of press brake and mould and the inhomogeneous characteristics of processed sheet metal. The processing errors of sheet metal can affect the assemblage, increasing subsequent repair to the mold and forming calibration, extending the product development cycle, restricting the further promotion and application of bending forming, especially on the forming high strength and high spring-back sheet metal. The PBH110-3100 CNC press brake in Jiangsu Yawei Co.Ltd. is studied to increase the bending precision of press brake in this study. The bending errors in press break are analyzed in depth according to the elastic mechanics theory, and the rule that the manufacturing precision of press brake affect the press precision is educed. The analysis results have real significance on improving the press precision and reliability of press brakes.
This specialist edition features key innovations in the science and engineering of new grinding processes, abrasives, tools, machines, and systems for a range of important industrial applications. ...Topics written by invited, internationally recognized authors review the advances and present results of research over a range of well-known grinding processes. A significant introductory review chapter explores innovations to achieve high productivity and very high precision in grinding. The reviewed applications range from grinding systems for very large lenses and reflectors, through to medium size grinding machine processes, and down to grinding very small components used in MEMS . Early research chapters explore the influence of grinding wheel topography on surface integrity and wheel wear. A novel chapter on abrasive processes also addresses the finishing of parts produced by additive manufacturing through mass finishing. Materials to be ground range from conventional engineering steels to aerospace materials, ceramics, and composites. The research findings highlight important new results for avoiding material sub-surface damage. The papers compiled in this book include references to many source publications which will be found invaluable for further research, such as new features introduced into control systems to improve process efficiency. The papers also reflect significant improvements and research findings relating to many aspects of grinding processes, including machines, materials, abrasives, wheel preparation, coolants, lubricants, and fluid delivery. Finally, a definitive chapter summarizes the optimal settings for high precision and the achievement of centerless grinding stability.
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