Journal articles: 'Multipass operation'

1

Jabri, Abdelouahhab, Abdellah El Barkany, and Ahmed El Khalfi. "Multipass Turning Operation Process Optimization Using Hybrid Genetic Simulated Annealing Algorithm." Modelling and Simulation in Engineering 2017 (2017): 1–10. http://dx.doi.org/10.1155/2017/1940635.

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For years, there has been increasing attention placed on the metal removal processes such as turning and milling operations; researchers from different areas focused on cutting conditions optimization. Cutting conditions optimization is a crucial step in Computer Aided Process Planning (CAPP); it aims to select optimal cutting parameters (such as cutting speed, feed rate, depth of cut, and number of passes) since these parameters affect production cost as well as production deadline. This paper deals with multipass turning operation optimization using a proposed Hybrid Genetic Simulated Annealing Algorithm (HSAGA). The SA-based local search is properly embedded into a GA search mechanism in order to move the GA away from being closed within local optima. The unit production cost is considered in this work as objective function to minimize under different practical and operational constraints. Taguchi method is then used to calibrate the parameters of proposed optimization approach. Finally, different results obtained by various optimization algorithms are compared to the obtained solution and the proposed hybrid evolutionary technique optimization has proved its effectiveness over other algorithms.

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Agapiou, J. S. "The Optimization of Machining Operations Based on a Combined Criterion, Part 2: Multipass Operations." Journal of Engineering for Industry 114, no. 4 (November 1, 1992): 508–13. http://dx.doi.org/10.1115/1.2900705.

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Part 1 of this paper [1] introduced a novel, rational objective function that incorporates both the production cost and total time criteria. In Part 2, the problem of determining the optimum machining conditions for multipass operations is investigated. The optimum number of machining passes is obtained through the dynamic programming technique and the optimum machining conditions for each pass are then determined based on the objective function discussed in Part 1. This approach can be very effectively applied to multistage machining since the optimum arrangement of the different operations can be determined by the dynamic programming method while the optimum cutting conditions for the operations in each machining stage are obtained using the method for single-pass while incorporating the objective function described in Part 1. A multipass turning process is theoretically analyzed and a computational procedure for obtaining the machining parameters is developed. Several examples are presented in order to illustrate the procedure and demonstrate the advantages of the proposed optimization technique for a multipass turning operation.

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Schaeffer, Ronald D., J. C. Sproul, J. O’Connell, C. van Vloten, and Arlan W. Mantz. "Multipass absorption cell designed for high temperature UHV operation." Applied Optics 28, no. 9 (May 1, 1989): 1710. http://dx.doi.org/10.1364/ao.28.001710.

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Ahmad, Nafis, Tomohisa Tanaka, and Yoshio Saito. "Optimization of Multipass Turning Parameters by Genetic Algorithm." Advanced Materials Research 264-265 (June 2011): 1545–50. http://dx.doi.org/10.4028/www.scientific.net/amr.264-265.1545.

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Optimization of cutting parameters is one of the key obstacles for CAD/CAM integration. In this work optimum cutting parameters, the best sequence, number, and type of passes of turning operation are determined by Genetic Algorithm (GA). Proposed optimization strategy ensures that no constraint will be violated at the optimum condition and determines the optimum number and type of passes such as rough, finish and semi-finish passes to complete a multipass turning operation. Here objective function is the unit production cost and constraints are limits of cutting force, power, tool life, stability condition, tool chip interface temperature, surface finish, feed rate to depth of cut ratio and the available rotational speed of spindle of machine tool.

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Moshinskii, A. I. "Analysis of the operation of cocurrent and countercurrent multipass heat exchangers." Theoretical Foundations of Chemical Engineering 40, no. 1 (January 2006): 68–79. http://dx.doi.org/10.1134/s0040579506010106.

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Schulz, M., R. Riedel, A. Willner, S. Düsterer, M. J. Prandolini, J. Feldhaus, B. Faatz, J. Rossbach, M. Drescher, and F. Tavella. "Pulsed operation of a high average power Yb:YAG thin-disk multipass amplifier." Optics Express 20, no. 5 (February 14, 2012): 5038. http://dx.doi.org/10.1364/oe.20.005038.

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Belloufi, Abderrahim, Mekki Assas, and Imane Rezgui. "Intelligent Selection of Machining Parameters in Multipass Turnings Using Firefly Algorithm." Modelling and Simulation in Engineering 2014 (2014): 1–6. http://dx.doi.org/10.1155/2014/592627.

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Determination of optimal cutting parameters is one of the most important elements in any process planning of metal parts. In this paper, a new optimization technique, firefly algorithm, is used for determining the machining parameters in a multipass turning operation model. The objective considered is minimization of production cost under a set of machining constraints. The optimization is carried out using firefly algorithm. An application example is presented and solved to illustrate the effectiveness of the presented algorithm.

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Sarkar, S., K. Ghosh, S. Mitra, and B. Bhattacharyya. "An Integrated Approach to Optimization of WEDM Combining Single-Pass and Multipass Cutting Operation." Materials and Manufacturing Processes 25, no. 8 (July 30, 2010): 799–807. http://dx.doi.org/10.1080/10426910903575848.

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Giuliani, G., S. Loreti, G. Salvetti, and E. Palange. "Multipass grating interferometer as output coupler for tunable, single-mode operation of large-bandwidth lasers." Optics Letters 10, no. 12 (December 1, 1985): 600. http://dx.doi.org/10.1364/ol.10.000600.

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Heinz, P., A. Seilmeier, and A. Piskarskas. "Picosecond Nd:YLF laser-multipass amplifier source pumped by pulsed diodes for the operation of powrful OPOs." Optics Communications 136, no. 5-6 (April 1997): 433–36. http://dx.doi.org/10.1016/s0030-4018(96)00733-x.

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Beausir, Benoît, László S. Tóth, and Olivier Bouaziz. "Simulation of Texture Development of Plane Carbon Steel in Multipass Rolling Using Analytical Flow Function." Materials Science Forum 495-497 (September 2005): 1603–8. http://dx.doi.org/10.4028/www.scientific.net/msf.495-497.1603.

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Using a simple analytical flow function, an analysis of the deformation field in symmetrical rolling has been carried out. The so-obtained varying velocity gradient is incorporated into the Taylor polycrystal plasticity model to simulate the development of the deformation texture. The initial discontinuity in the deformation field of the entering material element on the flow lines is also taken into account. Multiple passes of the material is simulated. A strong texture gradient is obtained in good agreement with experiments carried out for rolling of plane carbon steel. It is shown that the shear component of the texture is strongly related to the nature of multiple passes of the rolling operation.

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Friebel, Florence, Alain Pellegrina, Dimitris N. Papadopoulos, Patrice Camy, Jean-Louis Doualan, Richard Moncorgé, Patrick Georges, and Frédéric Druon. "Diode-pumped Yb:CaF $$_2$$ 2 multipass amplifier producing 50 mJ with dynamic analysis for high repetition rate operation." Applied Physics B 117, no. 2 (June 20, 2014): 597–603. http://dx.doi.org/10.1007/s00340-014-5872-4.

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Bock, Stefan, Franziska Marie Herrmann, Thomas Püschel, Uwe Helbig, René Gebhardt, Jakob Johannes Lötfering, Richard Pausch, et al. "Characterization of Accumulated B-Integral of Regenerative Amplifier Based CPA Systems." Crystals 10, no. 9 (September 22, 2020): 847. http://dx.doi.org/10.3390/cryst10090847.

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We report on a new approach to measure the accumulated B-integral in the regenerative and multipass amplifier stages of ultrashort-pulse high-power laser systems by B-integral-induced coupling between delayed test post-pulses and the main pulse. A numerical model for such non-linear pulse coupling is presented and compared to data taken at the high-power laser Draco with self-referenced spectral interferometry (SRSI). The dependence of the B-integral accumulated in the regenerative amplifier on its operation mode enables optimization strategies for extracted energy vs. collected B-integral. The technique presented here can, in principle, be applied to characterize any type of ultrashort pulse laser system and is essential for pre-pulse reduction.

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Pavel, Nicolaie, Kai Lünstedt, Klaus Petermann, and Günter Huber. "Multipass pumped Nd-based thin-disk lasers: continuous-wave laser operation at 106 and 09 μm with intracavity frequency doubling." Applied Optics 46, no. 34 (November 26, 2007): 8256. http://dx.doi.org/10.1364/ao.46.008256.

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Nandakumar, Mohanraj, Sankaran Ramalingam, Subashini Nallusamy, and Shriram Srinivasarangan Rangarajan. "Novel Efficacious Utilization of Fuzzy-Logic Controller-Based Two-Quadrant Operation of PMBLDC Motor Drive Systems for Multipass Hot-Steel Rolling Processes." Electronics 9, no. 6 (June 16, 2020): 1008. http://dx.doi.org/10.3390/electronics9061008.

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This study investigates the rough steel-rolling process, which requires repeated and rapid bidirectional hot-rolling operations and proposes a fuzzy-logic-controller-based brushless electric DC (BLDC) motor drive system for the same. We present a modeling of the hot-steel rough-rolling process using a set of metallurgical parameters and mechanical equations based on their operating conditions, specific features and characteristics, all obtained from actual data. The above equations and related parameters were modeled in MATLAB/Simulink schematic under variations in temperature and slab thickness corresponding using three different hot-rolled (HR) steel specimens. This led to the creation of a pair of speed and torque- profiles with alternate polarities for successive passes covering the entire rolling process for each steel specimen. A fuzzy logic controller utilized the above profiles on the motor shaft by incorporating speed and current feedback loops to attain reference speed and calculation of instantaneous stator currents of the BLDC motor with respective phase sequences, so as to satisfy the torque-profile. Simulation results showing the detailed performance of the drive system are presented. Further, experimental work on a BLD-motor-drive system is presented, along with loading arrangements and an arm controller embedded with control algorithm for the multi-loop feedback system used for the closed loop speed control. The efficacy of the new applications proposed in this study for the first time can be seen from the validation of the results from the BLDC motor with its fuzzy-based controller in terms of simulation and hardware, thereby serving to be an attractive alternative to conventional induction motor drive systems for steel rolling.

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TOCI, GUIDO, PIERO MAZZINGHI, and MATTEO VANNINI. "Design and performance of a diode laser spectrometer for a stratospheric aircraft." Laser and Particle Beams 17, no. 1 (January 1999): 59–67. http://dx.doi.org/10.1017/s0263034699171052.

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We report the instrument description and the results of the laboratory calibration and tests of a mid-infrared tunable diode spectrometer for in situ trace gas concentration measurements in the stratosphere operating on a stratospheric aircraft. The spectrometer is dedicated to the measurement of the HNO3 amount in the stratospheric aerosols by means of gas-phase absorption spectroscopy on molecular roto-vibrational lines in the mid-infrared, using a tunable diode laser and a multipass absorption cell. The instrument was specifically designed for operation aboard of the stratospheric aircraft M55 Geophysica, in the frame of the Airborne Platform for Earth observation (APE) project. The instrument is part of a measurement package for the measurement of the chemical content of Polar Stratospheric Clouds (PSCs) and other atmospheric aerosols. This system can be also used as a stand-alone detector of molecular trace gases. Design criteria include an efficient optical layout, with a very low sensitivity to the vibration and thermal stresses and a very small footprint, and a detection scheme based on the sweep integration technique for fast data acquisition and high signal-to-noise (S/N) ratio. We report a new set of testing measurements on ammonia as the calibration gas with one order of magnitude improvement with respect to what we previously reported.

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Tuzson, Béla, Manuel Graf, Jonas Ravelid, Philipp Scheidegger, André Kupferschmid, Herbert Looser, Randulph Paulo Morales, and Lukas Emmenegger. "A compact QCL spectrometer for mobile, high-precision methane sensing aboard drones." Atmospheric Measurement Techniques 13, no. 9 (September 7, 2020): 4715–26. http://dx.doi.org/10.5194/amt-13-4715-2020.

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Abstract. A compact and lightweight mid-infrared laser absorption spectrometer has been developed as a mobile sensing platform for high-precision atmospheric methane measurements aboard small unmanned aerial vehicles (UAVs). The instrument leverages two recent innovations: a novel segmented circular multipass cell (SC-MPC) design and a power-efficient, low-noise, intermittent continuous-wave (icw) laser driving approach. A system-on-chip hardware control and data acquisition system enables energy-efficient and fully autonomous operation. The integrated spectrometer weighs 2.1 kg (including battery) and consumes 18 W of electrical power, making it ideally suited for airborne monitoring applications. Under stable laboratory conditions, the device achieves a precision (1σ) of 1.1 ppb within 1 s and 0.1 ppb CH4 at 100 s averaging time. Detailed investigations were performed to identify and quantify the effects of various environmental factors, such as sudden changes in pressure, temperature, and mechanical vibrations, which commonly influence UAV-mounted sensors. The instrument was also deployed in two feasibility field studies: an artificial methane release experiment and a study on vertical profiles in the planetary boundary layer. In both cases, the spectrometer demonstrated its airborne capability of capturing subtle and/or sudden changes in atmospheric CH4 mole fractions and providing real-time data at 1 s time resolution.

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Goncharov, Nikolay G., Alexey A. Yushin, Oleg I. Kolesnikov, and Pavel A. Ponomarev. "Pipe metal and welded connection defect repair by cladding." SCIENCE & TECHNOLOGIES OIL AND OIL PRODUCTS PIPELINE TRANSPORTATION 10, no. 4 (August 31, 2020): 379–85. http://dx.doi.org/10.28999/2541-9595-2020-10-4-379-385.

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Cladding repair is the one of the most simple and least expensive repair technologies. It refers to both permanent and temporary repair methods. It reduces work costs and time of repair works while retaining the quality required by the statutory requirements. With the help of cladding repair, a significant number of defects of corrosion-mechanical origin can be eliminated. The problem of improving this technology is of utmost importance. The purpose of the present research is to develop the technology for effective and safe cladding repair of such defects as corrosion damages of pipe metal and such welded connection defects as incomplete groove filling, undercut, pores, strikes, slag inclusion. The following problems were solved to reach this goal: research of thermal cycles in the course of cladding, research of cladding modes, development of multipass repair technology, determination of allowable defect parameters, and detection of methods for optimal quality control of repaired areas. The specialists performed testing of full-scale pipe samples and circular joint of pipes, imitating the surface defects after cladding repair. The test results did not reveal the damage of metal and welded connection areas. Cladding repair allows recovering bearing capacity of pipeline to design level. This technology can be used in the works on shutdown pipelines and on pipelines under operation.

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Graf, Manuel, Philipp Scheidegger, André Kupferschmid, Herbert Looser, Thomas Peter, Ruud Dirksen, Lukas Emmenegger, and Béla Tuzson. "Compact and lightweight mid-infrared laser spectrometer for balloon-borne water vapor measurements in the UTLS." Atmospheric Measurement Techniques 14, no. 2 (February 22, 2021): 1365–78. http://dx.doi.org/10.5194/amt-14-1365-2021.

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Abstract. We describe the development, characterization, and first field deployments of a quantum cascade laser direct absorption spectrometer (QCLAS) for water vapor measurements in the upper troposphere and lower stratosphere (UTLS). The instrument is sufficiently small (30×23×11 cm3) and lightweight (3.9 kg) to be carried by meteorological balloons and used for frequent soundings in the UTLS. The spectrometer is a fully independent system, operating autonomously for the duration of a balloon flight. To achieve the required robustness, while satisfying stringent mass limitations, the concepts for optics and electronics have been fundamentally reconsidered compared to laboratory-based spectrometers. A significant enhancement of the mechanical and optical stability is achieved by integrating a newly designed segmented circular multipass cell which allows for 6 m optical path length in a very compact fashion. The H2O volume mixing ratio is retrieved by calibration-free evaluation of the spectral data, i.e., only relying on SI-traceable measurements and absorption line parameters. The open-path design reduces the risk of contamination and allows for fast response and thus high vertical resolution. Laboratory-based characterization experiments show an agreement within 2 % of reference measurements and a precision of 0.1 % under conditions comparable to the UTLS. The instrument successfully performed two balloon-borne test flights up to 28 km altitude. In the troposphere, the retrieved spectroscopic data show an excellent agreement with the accompanying measurements by a frost point hygrometer (CFH). At higher altitude, the quality of the spectral data remained unchanged, but outgassed water vapor within the instrument enclosure was hindering an accurate measurement of the atmospheric water vapor. Despite this limitation, these test flights demonstrated the operation of a compact laser spectrometer in the UTLS aboard a low-volume meteorological balloon, opening the perspective for future highly resolved, accurate, and cost-efficient soundings.

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Sobanski, Nicolas, Béla Tuzson, Philipp Scheidegger, Herbert Looser, André Kupferschmid, Maitane Iturrate, Céline Pascale, Christoph Hüglin, and Lukas Emmenegger. "Advances in High-Precision NO2 Measurement by Quantum Cascade Laser Absorption Spectroscopy." Applied Sciences 11, no. 3 (January 29, 2021): 1222. http://dx.doi.org/10.3390/app11031222.

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Nitrogen dioxide (NO2) is a major tropospheric air pollutant. Its concentration in the atmosphere is most frequently monitored indirectly by chemiluminescence detection or using direct light absorption in the visible range. Both techniques are subject to known biases from other trace gases (including water vapor), making accurate measurements at low concentration very challenging. Selective measurements of NO2 in the mid-infrared have been proposed as a promising alternative, but field deployments and comparisons with established techniques remain sparse. Here, we describe the development and validation of a quantum cascade laser-based spectrometer (QCLAS). It relies on a custom-made astigmatic multipass absorption cell and a recently developed low heat dissipation laser driving and a FPGA based data acquisition approach. We demonstrate a sub-pptv precision (1 σ) for NO2 after 150 s integration time. The instrument performance in terms of long-term stability, linearity and field operation capability was assessed in the laboratory and during a two-week inter-comparison campaign at a suburban air pollution monitoring station. Four NO2 instruments corresponding to three different detection techniques (chemiluminescence detection (CLD), cavity-attenuated phase shift (CAPS) spectroscopy and QCLAS) were deployed after calibrating them with three different referencing methods: gas-phase titration of NO, dynamic high-concentration cylinder dilution and permeation. These measurements show that QCLAS is an attractive alternative for high-precision NO2 monitoring. Used in dual-laser configuration, its capabilities can be extended to NO, thus allowing for unambiguous quantification of nitrogen oxides (NOx), which are of key importance in air quality assessments.

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Liu, Hui, Jie Shen, Cheng Ming Li, Zhe Shi, Jun Lin Qiu, and Li Zhong Xu. "Design of Process-Optimization Expert Control System for Vertical Sieve-Tray Tower and Grinding System." Applied Mechanics and Materials 433-435 (October 2013): 976–81. http://dx.doi.org/10.4028/www.scientific.net/amm.433-435.976.

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Vertical Sieve-tray Tower (VST) and grinding system are the key equipment of cement production line. The production of VST and grinding system involves complex physical and chemical mechanisms, harsh operating environment, fuzzy changing boundary conditions. It shows a multi-field coupling integrated complex multiphase. Yield, quality, efficiency, safety, energy conservation, emission reduction and other operational indicators of the system is not only interrelated but also mutual restraint. The physical relationship between system operation and system control performance indicator is not clear, so it is difficult to adopt traditional control methods based on mechanism modeling and model-based analysis. In view of that, a design of process-optimization expert control system is proposed for VST and grinding system. The system model is designed according to energy consumption and operating experience. It has optimal control of the entire procession for equipment operation and achieves minimum energy consumption to meet the production requirements.

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Muqaibel, Ali H., Moeness G. Amin, and Fauzia Ahmad. "Target Localization with a Single Antenna via Directional Multipath Exploitation." International Journal of Antennas and Propagation 2015 (2015): 1–10. http://dx.doi.org/10.1155/2015/510720.

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Target localization in urban sensing can benefit from angle dependency of the pulse shape at a radar receiver antenna. We propose a localization approach that utilizes the embedded directivity in ultra-wideband (UWB) antennas to estimate target positions. A single radar unit sensing operation of indoor targets surrounded by interior walls is considered, where interior wall multipaths are exploited to provide target cross-range. This exploitation assumes resolvability of the multipath components, which is made possible by the virtue of using UWB radar signals. The proposed approach is most attractive when only few multipaths are detectable due to propagation obstructions or owing to low signal-to-noise ratios. Both simulated and experimental data are used to demonstrate the effectiveness of the proposed approach.

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Xu, Yun, Shuliang Cao, Takeshi Sano, Tokiya Wakai, and Martino Reclari. "Experimental Investigation on Transient Pressure Characteristics in a Helico-Axial Multiphase Pump." Energies 12, no. 3 (January 31, 2019): 461. http://dx.doi.org/10.3390/en12030461.

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In oil and gas exploitation, the multiphase pump is a vital piece of equipment to guarantee production with high efficiency and stable operation. The complicated pattern of multiphase flow in the multiphase pump affects the pump performance; for this reason, the multiphase performance and the inner flow should be sufficiently investigated. In the present work, a liquid-gas multiphase pump is designed and manufactured, and then tested in a specialized test rig to reveal the transient pressure characteristics of the multiphase pump. Results show that the dominant frequency under water and water-air conditions is the blade passing frequency, which is induced by the rotor stator interaction. In the downstream of the impeller, the pressure fluctuation is obviously weakened, because the splitter-blade design could improve the control ability of flow pattern in the downstream region. In comparison with water condition, the pressure fluctuation of water-air condition greatly increases, and the multiples of impeller rotating frequency are stimulated due to the movement and merging of air bubbles. Finally, the correlation of transient pressure and phase distribution in impeller is revealed by using a high-speed camera. With the gradual pressure rise from impeller inlet to outlet, the relative movement and separation of two phases induce violent pressure fluctuations.

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Cisternas, Luis, Freddy Lucay, and Yesica Botero. "Trends in Modeling, Design, and Optimization of Multiphase Systems in Minerals Processing." Minerals 10, no. 1 (December 25, 2019): 22. http://dx.doi.org/10.3390/min10010022.

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Multiphase systems are important in minerals processing, and usually include solid–solid and solid–fluid systems, such as in wet grinding, flotation, dewatering, and magnetic separation, among several other unit operations. In this paper, the current trends in the process system engineering tasks of modeling, design, and optimization in multiphase systems, are analyzed. Different scales of size and time are included, and therefore, the analysis includes modeling at the molecular level (molecular dynamic modeling) and unit operation level (e.g., computational fluid dynamic, CFD), and the application of optimization for the design of a plant. New strategies for the modeling, design, and optimization of multiphase systems are also included, with a strong focus on the application of artificial intelligence (AI) and the combination of experimentation and modeling with response surface methodology (RSM). The integration of different modeling techniques such as CFD with discrete element simulation (DEM) and response surface methodology (RSM) with artificial neural networks (ANN) is included. The paper finishes with tools to study the uncertainty, both epistemic and stochastic, based on uncertainty and global sensitivity analyses, which is present in all mineral processing operations. It is shown that all of these areas are very active and can help in the understanding, operation, design, and optimization of mineral processing that involves multiphase systems. Future needs, such as meso-scale modeling, are highlighted.

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Kazakov, Aleksandr, and Anton Suprunovskiy. "Influence of operating firing field technologies on operational performance parameters." MATEC Web of Conferences 216 (2018): 02028. http://dx.doi.org/10.1051/matecconf/201821602028.

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At present, introduction of operating firing field technologies is one of the urgent tasks of the Russian railway transport, as their use can significantly improve operational performance parameters. The factors and conditions of transition to operating firing field control system for operational performance are investigated in this paper. It provides the analysis of the problems that arise during the work of the operating firing field and proposes measures for their elimination. Methods of mathematical and computer modeling using the author’s software product were used. A new approach to multilevel simulation of the work of a transport operating firing field has been developed, which involves the use of the mathematical apparatus of multiphase queuing systems.

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Aarsnes, Ulf Jakob, Florent Di Meglio, Robert Graham, and Ole Morten Aamo. "A Methodology for Classifying Operating Regimes in Underbalanced-Drilling Operations." SPE Journal 21, no. 02 (April 14, 2016): 423–33. http://dx.doi.org/10.2118/178920-pa.

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Summary This paper proposes an extension to an existing operating-envelope technique used for underbalanced drilling (UBD) to enhance control of bottomhole pressure and inflow parameters. With the use of an implementation of the drift-flux model (DFM) with boundary conditions typically encountered in underbalanced operations (UBO), a steady-state analysis of the system is performed. Through this analysis, four distinct operating regimes are identified, and the behavior in each of them is investigated through steady-state calculations and transient simulations. In particular, the analysis reveals that a section of the operating envelope previously believed to be unstable/transient is, in fact, stable/steady when a fixed choke opening is used as an independent variable in place of a fixed wellhead pressure (WHP). This results in the steady-state operating envelope being extended, and gives an increased understanding of the well behavior encountered in UBO toward enabling the introduction of automated control. Finally, we investigate the mechanism behind severe slugging in UBO and argue that the cause is different from that of the slugging encountered in production and multiphase transport.

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Drozdowski, Piotr. "Speed Control of Multiphase Cage Induction Motors Incorporating Supply Sequence." Archives of Electrical Engineering 63, no. 4 (December 11, 2014): 511–34. http://dx.doi.org/10.2478/aee-2014-0036.

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Abstract The subject of this paper is the control possibility of the multiphase cage induction motors having number of phases greater than 3. These motors have additional properties for speed control that distinguish them from the standard 3 phase motors: operation at various sequences of supplying voltages due to the inverter control and possible operation with few open-circuited phases. For each supply sequence different no load speeds at the same frequency can be obtained. This feature extends the motor application for miscellaneous drive demands including vector or scalar control. This depends mainly on the type of the stator winding for a given number of phases, since the principle of motor operation is based on co-operation of higher harmonics of magnetic field. Examples of operation are presented for a 9-phase motor, though general approach has been discussed. This motor was fed by a voltage source inverter at field oriented control with forced currents. The mathematical model of the motor was reduced to the form incorporating all most important physical features and appropriate for the control law formulation. The operation was illustrated for various supply sequences for “healthy” motor and for the motor operating at one phase broken. The obtained results have shown that parasitic influence of harmonic fields interaction has negligible influence on motor operation with respect to the useful coupling for properly designed stator winding.

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Onwubolu, G. C., and T. Kumalo. "Optimization of multipass turning operations with genetic algorithms." International Journal of Production Research 39, no. 16 (January 2001): 3727–45. http://dx.doi.org/10.1080/00207540110056153.

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Yeo, S. H. "A multipass optimization strategy for CNC lathe operations." International Journal of Production Economics 40, no. 2-3 (August 1995): 209–18. http://dx.doi.org/10.1016/0925-5273(95)00052-1.

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Rementsov, Andrey Nikolaevich, Victor Akimovich Egorov, and Nguen Huang Manh. "The New Approach to Optimization of Production – Technological Base of a Public Transport Enterprises Network on an Example of City Hanoi." Applied Mechanics and Materials 838 (June 2016): 39–46. http://dx.doi.org/10.4028/www.scientific.net/amm.838.39.

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In the article application of queuing systems model in the field of operation of motor transport is presented. The system of maintenance service (MS) and operating repair (OR) of the cars on technological base is considered as multichannel multiphase queuing system. The mathematical model allows to receive necessary parameters of system MS and OR and to optimize them on technical-economic criterion.

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Sönmez, A. İhsan, Adil Baykasoǧlu, Türkay Dereli, and İ. Hüseyin Fılız. "Dynamic optimization of multipass milling operations via geometric programming." International Journal of Machine Tools and Manufacture 39, no. 2 (February 1999): 297–320. http://dx.doi.org/10.1016/s0890-6955(98)00027-3.

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Yang, Xu, and Zongchang Qu. "Suction port design for a synchronal rotary multiphase pump." Proceedings of the Institution of Mechanical Engineers, Part E: Journal of Process Mechanical Engineering 232, no. 1 (November 10, 2016): 127–32. http://dx.doi.org/10.1177/0954408916678268.

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The synchronal rotary multiphase pump is a new type of positive-displacement pump for multiphase boosting. Given that the discharge valve is eliminated in the synchronal rotary multiphase pump, the radial suction port as used in traditional rotary compressors is no longer suitable for the gas–liquid working condition. Thus, a special design for the axial suction port is presented to ensure the synchronal rotary multiphase pump’s flexibility in handling work fluids with any inlet gas volume fraction. The design concept and working principle of the axial suction port of the synchronal rotary multiphase pump are introduced herein, and a geometrical model of the suction port is established to calculate the critical dimensions for the synchronal rotary multiphase pump manufacture. The results show that the axial suction port’s design avoids the inner compression of work fluids and the back flow from the outlet to the inlet of the synchronal rotary multiphase pump during operation, which meets the requirements for operating under the gas–liquid working condition. The matching between the variation in the sectional area of the suction port and the varying trend of suction volume results in an acceptable sectional velocity of suction flow. Although the designed axial suction port reduces the suction angle range in a revolution, the decrease in the volumetric efficiency is negligible.

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Ipanov, Aleksey, Michael Oshivalov, Konstantin Galyagin, Yuri Selyaninov, Maxim Savin, and Evgeny Vakhrameev. "MATHEMATICAL MODELING OF MULTIPHASE HYDROJET PUMP OPERATION." PNIPU Bulletin.The mechanical engineering, materials science 21, no. 2 (June 2019): 15–22. http://dx.doi.org/10.15593/2224-9877/2019.2.02.

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Fang, Xiurong, Jiang Wu, Xue Ou, and Fuqiang Yang. "Microstructural Characterization and Mechanical Properties of Ti-6Al-4V Alloy Subjected to Dynamic Plastic Deformation Achieved by Multipass Hammer Forging with Different Forging Temperatures." Advances in Materials Science and Engineering 2019 (August 27, 2019): 1–12. http://dx.doi.org/10.1155/2019/6410238.

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Dynamic plastic deformation (DPD) achieved by multipass hammer forging is one of the most important metal forming operations to create the excellent materials properties. By using the integrated approaches of optical microscope and scanning electron microscope, the forging temperature effects on the multipass hammer forging process and the forged properties of Ti-6Al-4V alloy were evaluated and the forging samples were controlled with a total height reduction of 50% by multipass strikes from 925°C to 1025°C. The results indicate that the forging temperature has a significant effect on morphology and the volume fraction of primary α phase, and the microstructural homogeneity is enhanced after multipass hammer forging. The alloy slip possibility and strain rates could be improved by multipass strikes, but the marginal efficiency decreases with the increased forging temperature. Besides, a forging process with an initial forging temperature a bit above β transformation and finishing the forging a little below the β transformation is suggested to balance the forging deformation resistance and forged mechanical properties.

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Chen, Mu-Chen, and Kai-Ying Chen. "Optimization of multipass turning operations with genetic algorithms: A note." International Journal of Production Research 41, no. 14 (January 2003): 3385–88. http://dx.doi.org/10.1080/0020754031000118143.

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Sastri, Tep. "Multipass Seasonal Adjustment Filter." Management Science 35, no. 1 (January 1989): 100–123. http://dx.doi.org/10.1287/mnsc.35.1.100.

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Mohan, E., and U. Natarajan. "Experimental Investigation on Boring Tool Vibration Control Using MR Fluid Damper." Journal of Advanced Manufacturing Systems 15, no. 01 (February 17, 2016): 13–25. http://dx.doi.org/10.1142/s0219686716500025.

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In the manufacturing industry, most of the components are made by machining operations. The performance of the product to a large extent is dependent on the accuracy and consistency of the machining processes. Various parameters are considered to achieve the high quality of the machining. Out of which, vibration is one of the important parameters that will lead poor quality of the product and also reduce the tool life. Vibrations are induced by metal cutting operation during machining. Turning operations and especially boring operations are associated with severe vibration-related problems. Boring operation is often done with a boring bar, which is necessarily long and slender so that it can fit into the multipart work piece geometry. Such tools are lack of dynamic stiffness and stability, this manufacturing operation is repeatedly plagued with self-excited vibrations known as chatter. Magnetorheological (MR) fluid is employed in this research work to control the vibration of a boring tool. The MR fluid damper has received great attention due to its ability to reversibly change from a free flowing, linear, viscous liquid to a semi-solid when exposed to magnetic fields in just a few milliseconds and was also found to be effective in suppressing tool vibration. Vibration control during machining process is an important tactic to suppress the chatter vibration. The aim of this approach is to reduce the relative displacements between the tool and the work piece during the machining process.

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Sohrabinasab, Yousuf, and Babak Ganji. "A comprehensive electromagnetic simulation model for switched reluctance motor operating under multiphase excitation." Engineering review 39, no. 3 (June 17, 2019): 302–9. http://dx.doi.org/10.30765/er.39.3.11.

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In the present paper, a comprehensive electromagnetic simulation model based on finite element method (FEM) is introduced for the switched reluctance motor (SRM) by which important electromagnetic characteristics are predicted for the multiphase excitation mode. The inputs of the model are the design data and control parameters and it considers different arrangements of the phase winding connections. The simulation model is developed totally in ANSYS parametric design language (APDL) as a parametric model and it can be used easily for different types of the SRM. Carrying out 2D finite element transient analysis in the simulation model, flux density waveforms within the motor are predicted and a procedure is developed for core loss determination of the SRM operating under multiphase excitation. Applying the introduced simulation model to an 8/6 SRM, simulation results are presented for operation with simultaneous two- phase excitation.

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Bleed, Peter. "Operations Research and Archaeology." American Antiquity 56, no. 1 (January 1991): 19–35. http://dx.doi.org/10.2307/280969.

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Operations research is the systematic study of resource utilization through the manipulation of conceptual models. Used most often by engineers and managers, these models also have potential application in archaeology. Event tree analysis, which models multipart systems with a number of potential consequences resulting from a series of events, makes it possible to analyze artifact-production processes or the operation of complex economic activities such as hunting. Fault tree analysis models the interactions of factors that can cause a technological system to fail. It offers a framework for the interpretation of archaeological remains such as flintlock firearm parts at Indian and Euroamerican sites of the Great Plains.

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Cecconello, Elsa, Endrias G. Asgedom, and Walter Söllner. "Removal of all time-varying sea-surface effects by source deghosting and demultiple." GEOPHYSICS 84, no. 6 (November 1, 2019): T347—T362. http://dx.doi.org/10.1190/geo2018-0879.1.

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Seismic source deghosting and sea-surface-related demultiple have been long-standing problems in marine seismic data processing. Although the receiver ghost problem may be considered as solved by using collocated measurement of pressure and normal velocity wavefields, the source deghosting and demultiple algorithms are still limited by assumptions related to the sea-surface condition. We have investigated the impact of a time-varying rough sea surface on source deghosting and demultiple. Starting from Rayleigh’s reciprocity theorem for time-varying sea surfaces, we uncover a fundamental limitation for source deghosting of time-dependent wavefields, such as marine seismic data that contain a receiver ghost or sea-surface-related multiples. We use simple synthetic examples to study the impact of source deghosting on sea-surface-related multiples. To resolve this limitation, we derive a method for simultaneous source deghosting and sea-surface-related demultiple for time-variant wavefields. Finally, we use the complex geologic model Sigsbee 2B first to illustrate that the source deghosting operation brings significant errors when applied to a data set containing sea-surface multiples. Second, we find that this problem can be resolved by simultaneously performing source deghosting and demultiple operations even in the presence of time-varying sea surfaces.

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Shahid, Salman, Sharul Sham Dol, Abdul Qader Hasan, Omar Mustafa Kassem, Mohamed S. Gadala, and Mohd Shiraz Aris. "A Review on Electrical Submersible Pump Head Losses and Methods to Analyze Two-Phase Performance Curve." WSEAS TRANSACTIONS ON FLUID MECHANICS 16 (February 9, 2021): 14–31. http://dx.doi.org/10.37394/232013.2021.16.3.

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Electrical submersible pumps (ESP) are referred to as a pump classification whose applications arebased upon transporting fluids from submersible elevations towards a fixed pipeline. Specific ESP pumps areutilized in offshore oil and gas facilities that are frequently employed in transport of Liquefied Natural Gas(LNG) terminals. Transport of LNG is a multiphase process that causes operational challenges for ESP due topresence of air pockets and air bubbles; presenting difficulties, such as cavitation and degradation to pumpcomponents. This performance degradation causes an economic risk to companies as well as a risk to pumpperformance capabilities, as it will not be able to pump with the same pressure again. Operational references formultiphase flow in ESP are limited; thus, this research paper reports multistage pumping, review offundamentals, previous experimental as well as modelling work benefitting future literature for a potentialsolution. Industries consume power to cope up with the losses associated with pumping two-phase fluidscausing company’s fortune. Preceding experimental work on single along with multiphase flow illustrate adistinct flow pattern surrounding the area around pump impeller while the pump is in operation. Throughexperimental observation, four flow patterns were observed and studied when gas was varied at different flowrates. Increasing the intake pressure proved to increase pump performance at two-phase flow. Experimentalstudy of multiphase flow with LNG fluid is expensive; thus, experimental validation is accomplished on asingle stage pump with external intervention of air bubbles to simulate LNG vaporization at fixed pressure andtemperature difference.

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Wun Moh, Hsiao, Erni Dharma Putra, and Rahel Yusuf. "Application of dynamic simulation to assess the effectiveness of well clean-up in a horizontal gas well." APPEA Journal 57, no. 2 (2017): 617. http://dx.doi.org/10.1071/aj16246.

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Well clean-up operation involves the removal of drilling and completion fluids from the wellbore before diverting the well to production facilities. Natural flow clean-up is preferred due to its relatively low cost and simplicity. Depending on the weight of the initial contents in the wellbore and the reservoir properties, artificial lift assisted clean-up such as nitrogen injection through coiled tubing may be required for some wells to ensure the well clean-up objectives are achieved. Well clean-up is transient in nature thus necessitating the need for a dynamic simulation approach to assess the effectiveness of different clean-up options and arrive at the optimal procedure before embarking on the actual field operation. In the current study, a comprehensive-multiphase-transient-simulator (OLGA) was used to predict the clean-up of a gas well with relatively short horizontal open-hole section and low reservoir pressure. Dynamic simulations of clean-up operations for different scenarios such as mud cake lift-off pressures and uncertainties in well productivity were conducted to assess the effectiveness of natural clean-up. Well clean-up failure could lead to impaired deliverability and potential for preferential flow hotspots. The study also assessed if coiled tubing-assisted operations would be beneficial in cases of natural clean-up being ineffective. This paper demonstrates the importance of using transient simulations to provide useful insights into flow and pressure dynamics inside the wellbore during clean-up which can help engineers to predict, design and optimise well clean-up operations, thus increasing the probability of a successful clean-up operation.

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Lee, Yi Zheng, and S. G. Ponnambalam. "Optimisation of multipass turning operations using PSO and GA-AIS algorithms." International Journal of Production Research 50, no. 22 (November 15, 2012): 6499–518. http://dx.doi.org/10.1080/00207543.2011.653450.

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Kee, P. K. "Alternative optimisation strategies and CAM software for multipass rough turning operations." International Journal of Advanced Manufacturing Technology 10, no. 5 (September 1995): 287–98. http://dx.doi.org/10.1007/bf01178982.

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Selishchev, Ivan Alekseevich, and Svetlana Aleksandrovna Oleinikova. "Mathematical model and algorithm for solving the problem of planning the operation of multiphase systems with heterogeneous resources and time limits." Программные системы и вычислительные методы, no. 1 (January 2021): 35–45. http://dx.doi.org/10.7256/2454-0714.2021.1.35005.

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The object of this research is the modern service and production systems, the specific functioning of which lies in a set of sequential and parallel operations with a random duration. A fundamental peculiarity of such systems is the stochastic nature of the duration of a single operation, which depends not only on the external random factors, but also on the choice of resources, and namely on the operator. This substantiates the parallel solution of the task on making a schedule of mutually dependent operations and the task on assigning the operators. In the conditions of resource and time limits, this task is NP difficult and requires the development of algorithms for developing the solution that is close to optimal in the limited time. For the development of mathematical and algorithmic software to solve this task, the author used the critical path method and PERT method, incident wave method, and methods for solving the assignment tasks. As a result, the author acquired a mathematical model that considers the stochastic nature of the duration of a single operation, which depends not only on random factors, but also on the operators. Based on such model, is formulated the optimization task that allows finding the launch time and the corresponding operators to gain the most profit. Based on the analysis of existing approaches and the specificity of the task at hand, the author proposes the algorithm for solving the task founded on successive refinement of the time characteristics of operations.

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Gao, Yue, Bo Chao Huai, Kai Ji, Fei Xiong Yuan, Jun Zhu, and Bin Hua. "AC Drive System with Multiphase Induction Motor for High Power Mining Haul Trucks." Applied Mechanics and Materials 610 (August 2014): 117–22. http://dx.doi.org/10.4028/www.scientific.net/amm.610.117.

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Electric mining haul trucks are one of the most challenging applications of power electronics in automotive systems. This paper presents some advances of AC drive system with multiphase induction motor in high power mining haul trucks used in the special operation and environment. It is established that the use of inverter-fed dual three-phase (DTP) induction motors with vector control is the preferred solution to reach the required high starting torque, widely variable-speed range and good dynamic performance required by these vehicles. Key technologies and design features for the drive systems under extreme operating conditions are discussed.

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Janaszek, M. "Structures of vector control of n-phase motor drives based on generalized Clarke transformation." Bulletin of the Polish Academy of Sciences Technical Sciences 64, no. 4 (December 1, 2016): 865–72. http://dx.doi.org/10.1515/bpasts-2016-0094.

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Abstract The paper presents vector control structures for n-phase AC motors derived from generalized Clarke transformation. In contrast to known works, where authors operate on generalized formulas of the Clarke transformation, in this work, only a number of actually used phases, of mostly industrial purposes, are considered (n = 5, 6, 2×3). This allows to perform control calculations in stationary orthogonal coordinates aβ or rotating dq. There are implementations of different control strategies: ROC (rotor-oriented control) or FOC (field-oriented control). Next, the paper presents the novel concept of a voltage modulator designed for multi-phase drive systems. Operation of the modulator is based on the extended Clarke transformation for multiphase systems. A mathematical model of the multiphase voltage modulator, operating in open-loop and closed-loop current control has been presented. Some selected oscillograms of voltage and current waveform, which illustrate properties of proposed control structures have been presented.

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Zheng, Zi Wei. "Iterative Channel Estimation for the Chinese Digital Television Terrestrial Broadcasting Systems with the Multiple-Antenna Receivers." Advanced Engineering Forum 6-7 (September 2012): 439–44. http://dx.doi.org/10.4028/www.scientific.net/aef.6-7.439.

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Orthogonal frequency division multiplexing is an effective against multipath fading and high data throughput wireless channel transmission technology. Assistance with the inverse fast Fourier transform and fast Fourier transform operation, orthogonal frequency division multiplexing modulation and demodulation operations of the system convenient and convenient hardware implementation, orthogonal frequency division multiplexing, so in the modern digital television terrestrial broadcasting the system is widely used to support high performance bandwidth-efficient multimedia services. Broadband multi-carrier orthogonal frequency division multiplexing with multi-antenna and multi-antenna receiving system, to increase the diversity gain and improve the capacity of the system in different multipath fading channel. Accurate channel estimation in a simple channel equalization and decoding of broadband multi-carrier orthogonal frequency division multiple-antenna receiver and channel estimation accuracy and multiplexing system is very important, is the key to the performance of the overall broadband multi-carrier orthogonal frequency division multiplexing system in the multi-antenna receiver bit error rate. In this paper, iterative channel estimation to plan for digital terrestrial television broadcasting broadband multi-carrier orthogonal frequency division multiple antenna receiver multiplexing system proposal.

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Ewin, A. J., and K. V. Reed. "A programmable CCD driver circuit for multiphase CCD operation." IEEE Transactions on Nuclear Science 36, no. 1 (1989): 891–97. http://dx.doi.org/10.1109/23.34572.

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Wang, Fang, and Mark A. Burns. "Multiphase bioreaction microsystem with automated on-chip droplet operation." Lab on a Chip 10, no. 10 (2010): 1308. http://dx.doi.org/10.1039/b925705e.

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Journal articles on the topic 'Multipass operation'

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