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Jesse F Giron - One of the best experts on this subject based on the ideXlab platform.
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nemchinov dyson solutions of the two dimensional axisymmetric inviscid compressible flow equations
Physics of Fluids, 2020Co-Authors: Jesse F Giron, Scott D Ramsey, Roy S BatyAbstract:We investigate the two-dimensional (2D) inviscid compressible flow equations in axisymmetric Coordinates, constrained by an ideal gas equation of state. Beginning with the assumption that the 2D velocity field is space–time separable and linearly variable in each corresponding Spatial Coordinate, we proceed to derive an infinite family of elliptic or hyperbolic, uniformly expanding or contracting “gas cloud” solutions. Construction of specific example solutions belonging to this family is dependent on the solution of a system of nonlinear, coupled, second-order ordinary differential equations and the prescription of an additional physical process of interest (e.g., uniform temperature or uniform entropy flow). The physical and computational implications of these solutions as pertaining to quantitative code verification or model qualification studies are discussed in some detail.
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nemchinov dyson solutions of the two dimensional axisymmetric inviscid compressible flow equations
arXiv: Fluid Dynamics, 2020Co-Authors: Jesse F Giron, Scott D Ramsey, Roy S BatyAbstract:We investigate the two-dimensional ($2$D) inviscid compressible flow equations in axisymmetric Coordinates, constrained by an ideal gas equation of state (EOS). Beginning with the assumption that the $2$D velocity field is space-time separable and linearly variable in each corresponding Spatial Coordinate, we proceed to derive an infinite family of elliptic or hyperbolic, uniformly expanding or contracting ``gas cloud'' solutions. Construction of specific example solutions belonging to this family is dependent on the solution of a system of nonlinear, coupled, second-order ordinary differential equations, and the prescription of an additional physical process of interest (e.g., uniform temperature or uniform entropy flow). The physical and computational implications of these solutions as pertaining to quantitative code verification or model qualification studies are discussed in some detail.
Luca Mastrogiacomo - One of the best experts on this subject based on the ideXlab platform.
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ESDA2008-59296 THE PROBLEM OF DISTRIBUTED WIRELESS SENSORS POSITIONING IN THE MOBILE Spatial Coordinate MEASURING SYSTEM (MSCMS)
2020Co-Authors: Fiorenzo Franceschini, Domenico Maisano, Maurizio Galetto, Luca MastrogiacomoAbstract:ABSTRACT Mobile Spatial Coordinate Measuring System (MScMS) is a wireless-sensor-network based system developed at the Industrial Metrology and Quality Engineering Laboratory of DISPEA -Politecnico di Torino. It has been designed to perform simple and rapid indoor dimensional measurements of medium-large size objects (large scale metrology). It is made up of three basic parts: a "constellation" of wireless devices (Crickets), a mobile probe, and a PC to store and elaborate data. Crickets and mobile probe use ultrasound (US) transceivers in order to evaluate mutual distances. Each US device has a communication range limited by a cone of transmission within a nominal opening angle of about 170° and a maximum distance of no more than 8 m. The mobile probe location in the working volume is obtained by a trilateration, consequently it should communicate with at least 4 constellation devices at once. The system makes it possible to calculate the position -in terms of Spatial Coordinates -of the object points "touched" by the probe. Acquired data are then available for different types of elaboration (determination of distances, curves or surfaces of measured objects). During the system set-up, the constellation Crickets (beacons) are manually placed in the working volume (we define this operation as "positioning"). After that, their Coordinates are determined as much precisely as possible (this operation is said "location"). The positioning of constellation devices is one of the most critical aspects in the system set-up. In principle, Crickets can be arranged without restrictions all around the measured object. However, the number and position of network devices are strongly related to the dimensions and shape of both the measuring volume and the measured object. The accuracy in the location of constellation devices is fundamental for the accuracy of the Coordinates of the touched points during measurement operation. It is important to assure a full coverage of the space served by network devices by a proper alignment of US transmitters. For that reason, an ad hoc software "pre-processor" has been developed in order to help the operator in positioning and locating constellation devices in the working volume, according to the measuring space and the measured object dimensional characteristics. The aim of the paper is to introduce and describe this computer-assisted approach. Some preliminary results of experimental tests carried out on the system prototype are also presented and discussed
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corrective algorithms for measurement improvement in mscms ii mobile Spatial Coordinate measurement system
Precision Engineering-journal of The International Societies for Precision Engineering and Nanotechnology, 2013Co-Authors: Maurizio Galetto, Luca MastrogiacomoAbstract:Abstract This paper presents a set of algorithms for the correction of measurement errors of a prototype system designed for large scale dimensional metrology (LSDM) applications. The system, developed in the Quality and Industrial Metrology Laboratory of Politecnico di Torino, is based on the principles of photogrammetry and consists of a set of cameras wirelessly connected to a central unit able to track the position of a portable contact probe. Due to its architecture the system is affected by several systematic error sources. This paper addresses some of them: the distortion of the lenses, the dimension of the probe tip and the kinematic of the probe. By means of the implementation of appropriate mathematical correction models, the overall system performance is significantly improved as shown by the conducted tests.
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on line diagnostics in the mobile Spatial Coordinate measuring system mscms
Precision Engineering-journal of The International Societies for Precision Engineering and Nanotechnology, 2009Co-Authors: Fiorenzo Franceschini, Maurizio Galetto, Domenico Augusto Francesco Maisano, Luca MastrogiacomoAbstract:Abstract Mobile Spatial Coordinate Measuring System (MScMS) is a wireless-sensor-network based system developed at the industrial metrology and quality engineering laboratory of DISPEA – Politecnico di Torino. It has been designed to perform simple and rapid indoor dimensional measurements of large-size volumes (large-scale metrology). It is made up of three basic parts: a “constellation” of wireless devices (Crickets), a mobile probe, and a PC to store and elaborate data. Crickets and mobile probe utilize ultrasound (US) transceivers in order to evaluate mutual distances. The system makes it possible to calculate the position – in terms of Spatial Coordinates – of the object points “touched” by the probe. Acquired data are then available for different types of elaboration (determination of distances, curves or surfaces of measured objects). In order to protect the system against causes of error such as, for example, US signal diffraction and reflection, external uncontrolled US sources (key jingling, neon blinking, etc.), or software non-acceptable solutions, MScMS implements some statistical tests for on-line diagnostics. Three of them are deeply analyzed in this paper: “energy model-based diagnostics”, “distance model-based diagnostics”, and “sensor physical diagnostics”. For each measurement, if all these tests are satisfied at once, the measured result may be considered acceptable with a specific confidence coefficient. Otherwise, the measurement is rejected. After a general description of the MScMS, the paper focuses on the description of these three on-line diagnostic tools. Some preliminary results achieved by the system prototype are also presented and discussed.
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Mobile Spatial Coordinate measuring system (MScMS) and CMMs: a structured comparison
The International Journal of Advanced Manufacturing Technology, 2009Co-Authors: Fiorenzo Franceschini, Domenico Maisano, Luca MastrogiacomoAbstract:In many branches of industry, most of manufacturing efforts are directed toward producing objects of specific forms and dimensions. Dimensional measurement is an important part of the production cycle, to check products compliance with specifications. For this, many substantial improvements in the existing technologies have been made, and new measuring systems have been introduced. This paper briefly introduces a recent measuring system— mobile Spatial Coordinate measuring system (MScMS)—which is suitable for performing dimensional measurements of large-size objects (dimension on the order of tens of meters). MScMS, thanks to its distributed wireless sensor network nature, is portable and can be easily arranged around the measured object. Furthermore, it does not require complex setup operations before being ready to perform measurements. After describing how the system works, we will compare it with well-tested and widespread instruments such as traditional Coordinate measuring machines (CMMs), showing analogies and differences. The comparison is structured on the basis of different criteria, which are analyzed in detail in the first part of the paper. Although being able to perform similar measurements, CMMs and MScMS are different in technological features. CMMs are able to achieve higher level of accuracy, while MScMS is more flexible, cheap, and can be important to simplify the current measuring practices within large-scale industrial metrology. It can be concluded that these systems can easily coexist, as each system is suitable for specific applications.
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mobile Spatial Coordinate measuring system mscms introduction to the system
8th A.I.Te.M. Conference “Enhancing the science of manufacturing”, 2007Co-Authors: Fiorenzo Franceschini, Maurizio Galetto, Domenico Augusto Francesco Maisano, Luca MastrogiacomoAbstract:In many industrial fields (for example, automotive and aerospace) dimensional measurements of large size objects should be easily and rapidly taken. Nowadays, the problem can be handled using many metrological systems, based on different technologies (optical, mechanical, electromagnetic, etc.). Each of these systems is more or less adequate, depending on measuring conditions, a user's experience and skill, or other factors like time, cost, dimensions, accurateness, portability, etc. In general for measuring medium-large size objects, portable systems can be preferred to fixed systems. Transferring the measuring system to the measured object place is often more practical than vice-versa. The purpose of this paper is to introduce a new system called Mobile Spatial Coordinate Measuring System (MScMS). The system has been designed to perform dimensional measurements of medium-large size objects. MScMS is made up of three basic parts: a ‘constellation’ of wireless devices, liberally distributed around the wor...
Roy S Baty - One of the best experts on this subject based on the ideXlab platform.
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nemchinov dyson solutions of the two dimensional axisymmetric inviscid compressible flow equations
Physics of Fluids, 2020Co-Authors: Jesse F Giron, Scott D Ramsey, Roy S BatyAbstract:We investigate the two-dimensional (2D) inviscid compressible flow equations in axisymmetric Coordinates, constrained by an ideal gas equation of state. Beginning with the assumption that the 2D velocity field is space–time separable and linearly variable in each corresponding Spatial Coordinate, we proceed to derive an infinite family of elliptic or hyperbolic, uniformly expanding or contracting “gas cloud” solutions. Construction of specific example solutions belonging to this family is dependent on the solution of a system of nonlinear, coupled, second-order ordinary differential equations and the prescription of an additional physical process of interest (e.g., uniform temperature or uniform entropy flow). The physical and computational implications of these solutions as pertaining to quantitative code verification or model qualification studies are discussed in some detail.
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nemchinov dyson solutions of the two dimensional axisymmetric inviscid compressible flow equations
arXiv: Fluid Dynamics, 2020Co-Authors: Jesse F Giron, Scott D Ramsey, Roy S BatyAbstract:We investigate the two-dimensional ($2$D) inviscid compressible flow equations in axisymmetric Coordinates, constrained by an ideal gas equation of state (EOS). Beginning with the assumption that the $2$D velocity field is space-time separable and linearly variable in each corresponding Spatial Coordinate, we proceed to derive an infinite family of elliptic or hyperbolic, uniformly expanding or contracting ``gas cloud'' solutions. Construction of specific example solutions belonging to this family is dependent on the solution of a system of nonlinear, coupled, second-order ordinary differential equations, and the prescription of an additional physical process of interest (e.g., uniform temperature or uniform entropy flow). The physical and computational implications of these solutions as pertaining to quantitative code verification or model qualification studies are discussed in some detail.
Fiorenzo Franceschini - One of the best experts on this subject based on the ideXlab platform.
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ESDA2008-59296 THE PROBLEM OF DISTRIBUTED WIRELESS SENSORS POSITIONING IN THE MOBILE Spatial Coordinate MEASURING SYSTEM (MSCMS)
2020Co-Authors: Fiorenzo Franceschini, Domenico Maisano, Maurizio Galetto, Luca MastrogiacomoAbstract:ABSTRACT Mobile Spatial Coordinate Measuring System (MScMS) is a wireless-sensor-network based system developed at the Industrial Metrology and Quality Engineering Laboratory of DISPEA -Politecnico di Torino. It has been designed to perform simple and rapid indoor dimensional measurements of medium-large size objects (large scale metrology). It is made up of three basic parts: a "constellation" of wireless devices (Crickets), a mobile probe, and a PC to store and elaborate data. Crickets and mobile probe use ultrasound (US) transceivers in order to evaluate mutual distances. Each US device has a communication range limited by a cone of transmission within a nominal opening angle of about 170° and a maximum distance of no more than 8 m. The mobile probe location in the working volume is obtained by a trilateration, consequently it should communicate with at least 4 constellation devices at once. The system makes it possible to calculate the position -in terms of Spatial Coordinates -of the object points "touched" by the probe. Acquired data are then available for different types of elaboration (determination of distances, curves or surfaces of measured objects). During the system set-up, the constellation Crickets (beacons) are manually placed in the working volume (we define this operation as "positioning"). After that, their Coordinates are determined as much precisely as possible (this operation is said "location"). The positioning of constellation devices is one of the most critical aspects in the system set-up. In principle, Crickets can be arranged without restrictions all around the measured object. However, the number and position of network devices are strongly related to the dimensions and shape of both the measuring volume and the measured object. The accuracy in the location of constellation devices is fundamental for the accuracy of the Coordinates of the touched points during measurement operation. It is important to assure a full coverage of the space served by network devices by a proper alignment of US transmitters. For that reason, an ad hoc software "pre-processor" has been developed in order to help the operator in positioning and locating constellation devices in the working volume, according to the measuring space and the measured object dimensional characteristics. The aim of the paper is to introduce and describe this computer-assisted approach. Some preliminary results of experimental tests carried out on the system prototype are also presented and discussed
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on line diagnostics in the mobile Spatial Coordinate measuring system mscms
Precision Engineering-journal of The International Societies for Precision Engineering and Nanotechnology, 2009Co-Authors: Fiorenzo Franceschini, Maurizio Galetto, Domenico Augusto Francesco Maisano, Luca MastrogiacomoAbstract:Abstract Mobile Spatial Coordinate Measuring System (MScMS) is a wireless-sensor-network based system developed at the industrial metrology and quality engineering laboratory of DISPEA – Politecnico di Torino. It has been designed to perform simple and rapid indoor dimensional measurements of large-size volumes (large-scale metrology). It is made up of three basic parts: a “constellation” of wireless devices (Crickets), a mobile probe, and a PC to store and elaborate data. Crickets and mobile probe utilize ultrasound (US) transceivers in order to evaluate mutual distances. The system makes it possible to calculate the position – in terms of Spatial Coordinates – of the object points “touched” by the probe. Acquired data are then available for different types of elaboration (determination of distances, curves or surfaces of measured objects). In order to protect the system against causes of error such as, for example, US signal diffraction and reflection, external uncontrolled US sources (key jingling, neon blinking, etc.), or software non-acceptable solutions, MScMS implements some statistical tests for on-line diagnostics. Three of them are deeply analyzed in this paper: “energy model-based diagnostics”, “distance model-based diagnostics”, and “sensor physical diagnostics”. For each measurement, if all these tests are satisfied at once, the measured result may be considered acceptable with a specific confidence coefficient. Otherwise, the measurement is rejected. After a general description of the MScMS, the paper focuses on the description of these three on-line diagnostic tools. Some preliminary results achieved by the system prototype are also presented and discussed.
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Mobile Spatial Coordinate measuring system (MScMS) and CMMs: a structured comparison
The International Journal of Advanced Manufacturing Technology, 2009Co-Authors: Fiorenzo Franceschini, Domenico Maisano, Luca MastrogiacomoAbstract:In many branches of industry, most of manufacturing efforts are directed toward producing objects of specific forms and dimensions. Dimensional measurement is an important part of the production cycle, to check products compliance with specifications. For this, many substantial improvements in the existing technologies have been made, and new measuring systems have been introduced. This paper briefly introduces a recent measuring system— mobile Spatial Coordinate measuring system (MScMS)—which is suitable for performing dimensional measurements of large-size objects (dimension on the order of tens of meters). MScMS, thanks to its distributed wireless sensor network nature, is portable and can be easily arranged around the measured object. Furthermore, it does not require complex setup operations before being ready to perform measurements. After describing how the system works, we will compare it with well-tested and widespread instruments such as traditional Coordinate measuring machines (CMMs), showing analogies and differences. The comparison is structured on the basis of different criteria, which are analyzed in detail in the first part of the paper. Although being able to perform similar measurements, CMMs and MScMS are different in technological features. CMMs are able to achieve higher level of accuracy, while MScMS is more flexible, cheap, and can be important to simplify the current measuring practices within large-scale industrial metrology. It can be concluded that these systems can easily coexist, as each system is suitable for specific applications.
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mobile Spatial Coordinate measuring system mscms introduction to the system
8th A.I.Te.M. Conference “Enhancing the science of manufacturing”, 2007Co-Authors: Fiorenzo Franceschini, Maurizio Galetto, Domenico Augusto Francesco Maisano, Luca MastrogiacomoAbstract:In many industrial fields (for example, automotive and aerospace) dimensional measurements of large size objects should be easily and rapidly taken. Nowadays, the problem can be handled using many metrological systems, based on different technologies (optical, mechanical, electromagnetic, etc.). Each of these systems is more or less adequate, depending on measuring conditions, a user's experience and skill, or other factors like time, cost, dimensions, accurateness, portability, etc. In general for measuring medium-large size objects, portable systems can be preferred to fixed systems. Transferring the measuring system to the measured object place is often more practical than vice-versa. The purpose of this paper is to introduce a new system called Mobile Spatial Coordinate Measuring System (MScMS). The system has been designed to perform dimensional measurements of medium-large size objects. MScMS is made up of three basic parts: a ‘constellation’ of wireless devices, liberally distributed around the wor...
T H Watanabe - One of the best experts on this subject based on the ideXlab platform.
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eulerian variational formulations and momentum conservation laws for kinetic plasma systems
Physics of Plasmas, 2018Co-Authors: H Sugama, M Nunami, S Satake, T H WatanabeAbstract:The Eulerian variational principle for the Vlasov-Poisson-Ampere system of equations in a general Coordinate system is presented. The invariance of the action integral under an arbitrary Spatial Coordinate transformation is used to obtain the momentum conservation law and the symmetric pressure in a more direct way than using the translational and rotational symmetries of the system. Next, the Eulerian variational principle is given for the collisionless drift kinetic equation, where particles' phase-space trajectories in given electromagnetic fields are described by Littlejohn's guiding center equations [R. G. Littlejohn, J. Plasma Phys. 29, 111 (1983)]. Then, it is shown that, in comparison with the conventional moment method, the invariance under a general Spatial Coordinate transformation yields a more convenient way to obtain the momentum balance as a three-dimensional vector equation in which the symmetric pressure tensor, the Lorentz force, and the magnetization current are properly expressed. Furthermore, the Eulerian formulation is presented for the extended drift kinetic system, for which, in addition to the drift kinetic equations for the distribution functions of all particle species, the quasineutrality condition and Ampere's law to determine the self-consistent electromagnetic fields are given. Again, the momentum conservation law for the extended system is derived from the invariance under the general Spatial Coordinate transformation. Besides, the momentum balances are investigated for the cases where the collision and/or external source terms are added to the Vlasov and drift kinetic equations.The Eulerian variational principle for the Vlasov-Poisson-Ampere system of equations in a general Coordinate system is presented. The invariance of the action integral under an arbitrary Spatial Coordinate transformation is used to obtain the momentum conservation law and the symmetric pressure in a more direct way than using the translational and rotational symmetries of the system. Next, the Eulerian variational principle is given for the collisionless drift kinetic equation, where particles' phase-space trajectories in given electromagnetic fields are described by Littlejohn's guiding center equations [R. G. Littlejohn, J. Plasma Phys. 29, 111 (1983)]. Then, it is shown that, in comparison with the conventional moment method, the invariance under a general Spatial Coordinate transformation yields a more convenient way to obtain the momentum balance as a three-dimensional vector equation in which the symmetric pressure tensor, the Lorentz force, and the magnetization current are properly expressed. Furt...
