Dépouillements

Unstable characteristics and rotating stall in turbine brake operation of pump-turbines / Widmer, Christian in Transactions of the ASME . Journal of fluids engineering, Vol. 133 N° 4 (Avril 2011) 

Public ISBD [article]  in Transactions of the ASME . Journal of fluids engineering > Vol. 133 N° 4 (Avril 2011) . - 09 p. Titre : Unstable characteristics and rotating stall in turbine brake operation of pump-turbines Type de document : texte imprimé Auteurs : Widmer, Christian, Auteur ; Staubli, Thomas, Auteur ; Ledergerber, Nathan, Auteur Année de publication : 2011 Article en page(s) : 09 p. Note générale : Fluids engineering Langues : Anglais (eng) Mots-clés : Blades  Channel  flow  Flow  instability  Flow  simulation  Hydraulic  turbines  Pumps  Rotors  Stators  Vortices Index. décimale : 620.1 Essais des matériaux. Défauts des matériaux. Protection des matériaux Résumé : Reversible pump-turbines are versatile in the electricity market since they can be switched between pump and turbine operation within a few minutes. The emphasis on the design of the more sensitive pump flow however often leads to stability problems in no load or turbine brake operation. Unstable characteristics can be responsible for hydraulic system oscillations in these operating points. The cause of the unstable characteristics can be found in the blocking effect of either stationary vortex formation or rotating stall. The so-called unstable characteristic in turbine brake operation is defined by the change of sign of the slope of the head curve. This change of sign or “S-shape” can be traced back to flow recirculation and vortex formation within the runner and the vaneless space between runner and guide vanes. When approaching part load from sound turbine flow the vortices initially develop and collapse again. This unsteady vortex formation induces periodical pressure fluctuations. In the turbine brake operation at small guide vane openings the vortices increase in intensity, stabilize and circumferentially block the flow passages. This stationary vortex formation is associated with a total pressure rise over the machine and leads to the slope change of the characteristic. Rotating stall is a flow instability which extends from the runner, the vaneless space to the guide and the stay vane channels at large guide vane openings. A certain number of channels is blocked (rotating stall cell) while the other channels comprise sound flow. Due to a momentum exchange between rotor and stator at the front and the rear cell boundary, the cell is rotating with subsynchronous frequency of about 60 percent of the rotational speed for the investigated pump-turbine (nq = 45). The enforced rotating pressure distributions in the vaneless space lead to large dynamic radial forces on the runner. The mechanisms leading to stationary vortex formation and rotating stall were analyzed with a pump-turbine model by the means of numerical simulations and test rig measurements. It was found that stationary vortex formation and rotating stall have initially the same physical cause, but it depends on the mean convective acceleration within the guide vane channels, whether the vortex formations will rotate or not. Both phenomena lead to an unstable characteristic. DEWEY : 620.1 ISSN : 0098-2202 En ligne : http://asmedl.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=JFEGA400013300 [...] [article] Unstable characteristics and rotating stall in turbine brake operation of pump-turbines [texte imprimé] / Widmer, Christian, Auteur ; Staubli, Thomas, Auteur ; Ledergerber, Nathan, Auteur . - 2011 . - 09 p. Fluids engineering Langues : Anglais (eng) in Transactions of the ASME . Journal of fluids engineering > Vol. 133 N° 4 (Avril 2011) . - 09 p. Mots-clés : Blades  Channel  flow  Flow  instability  Flow  simulation  Hydraulic  turbines  Pumps  Rotors  Stators  Vortices Index. décimale : 620.1 Essais des matériaux. Défauts des matériaux. Protection des matériaux Résumé : Reversible pump-turbines are versatile in the electricity market since they can be switched between pump and turbine operation within a few minutes. The emphasis on the design of the more sensitive pump flow however often leads to stability problems in no load or turbine brake operation. Unstable characteristics can be responsible for hydraulic system oscillations in these operating points. The cause of the unstable characteristics can be found in the blocking effect of either stationary vortex formation or rotating stall. The so-called unstable characteristic in turbine brake operation is defined by the change of sign of the slope of the head curve. This change of sign or “S-shape” can be traced back to flow recirculation and vortex formation within the runner and the vaneless space between runner and guide vanes. When approaching part load from sound turbine flow the vortices initially develop and collapse again. This unsteady vortex formation induces periodical pressure fluctuations. In the turbine brake operation at small guide vane openings the vortices increase in intensity, stabilize and circumferentially block the flow passages. This stationary vortex formation is associated with a total pressure rise over the machine and leads to the slope change of the characteristic. Rotating stall is a flow instability which extends from the runner, the vaneless space to the guide and the stay vane channels at large guide vane openings. A certain number of channels is blocked (rotating stall cell) while the other channels comprise sound flow. Due to a momentum exchange between rotor and stator at the front and the rear cell boundary, the cell is rotating with subsynchronous frequency of about 60 percent of the rotational speed for the investigated pump-turbine (nq = 45). The enforced rotating pressure distributions in the vaneless space lead to large dynamic radial forces on the runner. The mechanisms leading to stationary vortex formation and rotating stall were analyzed with a pump-turbine model by the means of numerical simulations and test rig measurements. It was found that stationary vortex formation and rotating stall have initially the same physical cause, but it depends on the mean convective acceleration within the guide vane channels, whether the vortex formations will rotate or not. Both phenomena lead to an unstable characteristic. DEWEY : 620.1 ISSN : 0098-2202 En ligne : http://asmedl.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=JFEGA400013300 [...]

Integrated motor/propulsor duct optimization for increased vehicle and propulsor performance / Huyer, Stephen A. in Transactions of the ASME . Journal of fluids engineering, Vol. 133 N° 4 (Avril 2011) 

Public ISBD [article]  in Transactions of the ASME . Journal of fluids engineering > Vol. 133 N° 4 (Avril 2011) . - 10 p. Titre : Integrated motor/propulsor duct optimization for increased vehicle and propulsor performance Type de document : texte imprimé Auteurs : Huyer, Stephen A., Auteur ; Dropkin, Amanda, Auteur Année de publication : 2011 Article en page(s) : 10 p. Note générale : Fluids engineering Langues : Anglais (eng) Mots-clés : Blades  Computational  fluid  dynamics  Design  engineering  Drag  Electric  motors  Flow  simulation  Navier-Stokes  equations  Optimisation  Pipe  flow  Propulsion  Rotors  Stators  Swirling  flow  Underwater  vehicles Index. décimale : 620.1 Essais des matériaux. Défauts des matériaux. Protection des matériaux Résumé : This paper presents a computational study to better understand the underlying fluid dynamics associated with various duct shapes and the resultant impact on both total vehicle drag and propulsor efficiency. A post-swirl propulsor configuration (downstream stator blade row) was selected with rotor and stator blade number kept constant. A generic undersea vehicle hull shape was chosen and the maximum shroud radius was required to lie within this body radius. A cylindrical rim-driven electric motor capable of generating a specific horsepower to achieve the design operational velocity required a set volume that established a design constraint limiting the shape of the duct. Individual duct shapes were designed to produce constant flow acceleration from upstream of the rotor blade row to downstream of the stator blade row. Ducts producing accelerating and decelerating flow were systematically examined. The axisymmetric Reynolds Averaged Navier–Stokes (RANS) version of fluent® was used to study the fluid dynamics associated with a range of accelerated and decelerated duct flow cases as well as provide the base total vehicle drag. For each given duct shape, the propeller blade design code, PBD 14.3, was used to generate an optimized rotor and stator. To provide fair comparisons, the maximum rotor radius was held constant with similar circulation distributions intended to generate equivalent amounts of thrust. Computations predicted that minimum vehicle drag was produced with a duct that produced zero mean flow acceleration. Ducted designs generating accelerating or decelerating flow increased drag. However, propulsive efficiency based exclusively on blade thrust and torque was significantly increased for accelerating flow through the duct and reduced for decelerating flow cases. Full 3D RANS flow simulations were then conducted for select test cases to quantify the specific blade, hull, and shroud forces and highlight the increased component drag produced by an operational propulsor, which reduced overall propulsive efficiency. From these results, a final optimized design was proposed. DEWEY : 620.1 ISSN : 0098-2202 En ligne : http://asmedl.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=JFEGA400013300 [...] [article] Integrated motor/propulsor duct optimization for increased vehicle and propulsor performance [texte imprimé] / Huyer, Stephen A., Auteur ; Dropkin, Amanda, Auteur . - 2011 . - 10 p. Fluids engineering Langues : Anglais (eng) in Transactions of the ASME . Journal of fluids engineering > Vol. 133 N° 4 (Avril 2011) . - 10 p. Mots-clés : Blades  Computational  fluid  dynamics  Design  engineering  Drag  Electric  motors  Flow  simulation  Navier-Stokes  equations  Optimisation  Pipe  flow  Propulsion  Rotors  Stators  Swirling  flow  Underwater  vehicles Index. décimale : 620.1 Essais des matériaux. Défauts des matériaux. Protection des matériaux Résumé : This paper presents a computational study to better understand the underlying fluid dynamics associated with various duct shapes and the resultant impact on both total vehicle drag and propulsor efficiency. A post-swirl propulsor configuration (downstream stator blade row) was selected with rotor and stator blade number kept constant. A generic undersea vehicle hull shape was chosen and the maximum shroud radius was required to lie within this body radius. A cylindrical rim-driven electric motor capable of generating a specific horsepower to achieve the design operational velocity required a set volume that established a design constraint limiting the shape of the duct. Individual duct shapes were designed to produce constant flow acceleration from upstream of the rotor blade row to downstream of the stator blade row. Ducts producing accelerating and decelerating flow were systematically examined. The axisymmetric Reynolds Averaged Navier–Stokes (RANS) version of fluent® was used to study the fluid dynamics associated with a range of accelerated and decelerated duct flow cases as well as provide the base total vehicle drag. For each given duct shape, the propeller blade design code, PBD 14.3, was used to generate an optimized rotor and stator. To provide fair comparisons, the maximum rotor radius was held constant with similar circulation distributions intended to generate equivalent amounts of thrust. Computations predicted that minimum vehicle drag was produced with a duct that produced zero mean flow acceleration. Ducted designs generating accelerating or decelerating flow increased drag. However, propulsive efficiency based exclusively on blade thrust and torque was significantly increased for accelerating flow through the duct and reduced for decelerating flow cases. Full 3D RANS flow simulations were then conducted for select test cases to quantify the specific blade, hull, and shroud forces and highlight the increased component drag produced by an operational propulsor, which reduced overall propulsive efficiency. From these results, a final optimized design was proposed. DEWEY : 620.1 ISSN : 0098-2202 En ligne : http://asmedl.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=JFEGA400013300 [...]

Computational fluid dynamic studies of vortex amplifier design for the nuclear industry—I. steady-state conditions / Parker, D. in Transactions of the ASME . Journal of fluids engineering, Vol. 133 N° 4 (Avril 2011) 

Public ISBD [article]  in Transactions of the ASME . Journal of fluids engineering > Vol. 133 N° 4 (Avril 2011) . - 16 p. Titre : Computational fluid dynamic studies of vortex amplifier design for the nuclear industry—I. steady-state conditions Type de document : texte imprimé Auteurs : Parker, D., Auteur ; Birch, M. J., Auteur ; Francis, J., Auteur Année de publication : 2011 Article en page(s) : 16 p. Note générale : Fluids engineering Langues : Anglais (eng) Mots-clés : Aerodynamics  Computational  fluid  dynamics  Flow  simulation  Mesh  generation  Smoke  Turbulence  Vortices Index. décimale : 620.1 Essais des matériaux. Défauts des matériaux. Protection des matériaux Résumé : In this study the effects of changes to the geometry of a vortex amplifier are investigated using computational fluid dynamics (CFD) techniques, in the context of glovebox operations for the nuclear industry. These investigations were required because of anomalous behavior identified when, for operational reasons, a long-established vortex amplifier design was reduced in scale. The aims were (i) to simulate both the anomalous back-flow into the glovebox through the vortex amplifier supply ports, and the precessing vortex core in the amplifier outlet, then (ii) to determine which of the various simulated geometries would best alleviate the supply port back-flow anomaly. Various changes to the geometry of the vortex amplifier were proposed; smoke and air tests were then used to identify a subset of these geometries for subsequent simulation using CFD techniques. Having verified the mesh resolution was sufficient to reproduce the required effects, the code was then validated by comparing the results of the steady-state simulations with the experimental data. The problem is challenging in terms of the range of geometrical and dynamic scales encountered, with consequent impact on mesh quality and turbulence modeling. The anomalous nonaxisymmetric reverse flow in the supply ports of the vortex amplifier has been captured and the mixing in both the chamber and the precessing vortex core has also been successfully reproduced. Finally, by simulating changes to the supply ports that could not be reproduced experimentally at an equivalent cost, the geometry most likely to alleviate the back-flow anomaly has been identified. DEWEY : 620.1 ISSN : 0098-2202 En ligne : http://asmedl.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=JFEGA400013300 [...] [article] Computational fluid dynamic studies of vortex amplifier design for the nuclear industry—I. steady-state conditions [texte imprimé] / Parker, D., Auteur ; Birch, M. J., Auteur ; Francis, J., Auteur . - 2011 . - 16 p. Fluids engineering Langues : Anglais (eng) in Transactions of the ASME . Journal of fluids engineering > Vol. 133 N° 4 (Avril 2011) . - 16 p. Mots-clés : Aerodynamics  Computational  fluid  dynamics  Flow  simulation  Mesh  generation  Smoke  Turbulence  Vortices Index. décimale : 620.1 Essais des matériaux. Défauts des matériaux. Protection des matériaux Résumé : In this study the effects of changes to the geometry of a vortex amplifier are investigated using computational fluid dynamics (CFD) techniques, in the context of glovebox operations for the nuclear industry. These investigations were required because of anomalous behavior identified when, for operational reasons, a long-established vortex amplifier design was reduced in scale. The aims were (i) to simulate both the anomalous back-flow into the glovebox through the vortex amplifier supply ports, and the precessing vortex core in the amplifier outlet, then (ii) to determine which of the various simulated geometries would best alleviate the supply port back-flow anomaly. Various changes to the geometry of the vortex amplifier were proposed; smoke and air tests were then used to identify a subset of these geometries for subsequent simulation using CFD techniques. Having verified the mesh resolution was sufficient to reproduce the required effects, the code was then validated by comparing the results of the steady-state simulations with the experimental data. The problem is challenging in terms of the range of geometrical and dynamic scales encountered, with consequent impact on mesh quality and turbulence modeling. The anomalous nonaxisymmetric reverse flow in the supply ports of the vortex amplifier has been captured and the mixing in both the chamber and the precessing vortex core has also been successfully reproduced. Finally, by simulating changes to the supply ports that could not be reproduced experimentally at an equivalent cost, the geometry most likely to alleviate the back-flow anomaly has been identified. DEWEY : 620.1 ISSN : 0098-2202 En ligne : http://asmedl.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=JFEGA400013300 [...]

Flow past a rotating cylinder at low and high rotation rates / Kumar, S. in Transactions of the ASME . Journal of fluids engineering, Vol. 133 N° 4 (Avril 2011) 

Public ISBD [article]  in Transactions of the ASME . Journal of fluids engineering > Vol. 133 N° 4 (Avril 2011) . - 09 p. Titre : Flow past a rotating cylinder at low and high rotation rates Type de document : texte imprimé Auteurs : Kumar, S., Auteur ; Cantu, C., Auteur ; Gonzalez, B., Auteur Année de publication : 2011 Article en page(s) : 09 p. Note générale : Fluids engineering Langues : Anglais (eng) Mots-clés : Bubbles  External  flows  Flow  visualisation  Laminar  flow  Pattern  formation  Vortices  Wakes Index. décimale : 620.1 Essais des matériaux. Défauts des matériaux. Protection des matériaux Résumé : Flow past a rotating circular cylinder is studied experimentally. The experiments are carried out in a water tunnel at Reynolds numbers of 200, 300, and 400 and nondimensional rotation rates (ratio of surface speed of the cylinder to the free stream velocity), alpha, varying from 0 to 5. The diagnostic is done by flow visualization using hydrogen bubble technique and quantitative measurements using a particle image velocimetry technique. We present the global view of the wake structure at the three Reynolds numbers and various rotation rates. Vortex shedding activity is observed to occur from alpha=0 to alpha~1.95, after which it is suppressed. Reynolds number is found to have a strong effect on the wake morphology near the suppression rotation rate, alpha=1.95. Interestingly, the vortex shedding activity again resumes in the range 4.34 DEWEY : 620.1 ISSN : 0742-4795 En ligne : http://scitation.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=JFEGA400013 [...] [article] Flow past a rotating cylinder at low and high rotation rates [texte imprimé] / Kumar, S., Auteur ; Cantu, C., Auteur ; Gonzalez, B., Auteur . - 2011 . - 09 p. Fluids engineering Langues : Anglais (eng) in Transactions of the ASME . Journal of fluids engineering > Vol. 133 N° 4 (Avril 2011) . - 09 p. Mots-clés : Bubbles  External  flows  Flow  visualisation  Laminar  flow  Pattern  formation  Vortices  Wakes Index. décimale : 620.1 Essais des matériaux. Défauts des matériaux. Protection des matériaux Résumé : Flow past a rotating circular cylinder is studied experimentally. The experiments are carried out in a water tunnel at Reynolds numbers of 200, 300, and 400 and nondimensional rotation rates (ratio of surface speed of the cylinder to the free stream velocity), alpha, varying from 0 to 5. The diagnostic is done by flow visualization using hydrogen bubble technique and quantitative measurements using a particle image velocimetry technique. We present the global view of the wake structure at the three Reynolds numbers and various rotation rates. Vortex shedding activity is observed to occur from alpha=0 to alpha~1.95, after which it is suppressed. Reynolds number is found to have a strong effect on the wake morphology near the suppression rotation rate, alpha=1.95. Interestingly, the vortex shedding activity again resumes in the range 4.34 DEWEY : 620.1 ISSN : 0742-4795 En ligne : http://scitation.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=JFEGA400013 [...]

Application of the Euler–Lagrange method to model developed hydrodynamic slugs in conduits / Guzmán, J. E. V. in Transactions of the ASME . Journal of fluids engineering, Vol. 133 N° 4 (Avril 2011) 

Public ISBD [article]  in Transactions of the ASME . Journal of fluids engineering > Vol. 133 N° 4 (Avril 2011) . - 09 p. Titre : Application of the Euler–Lagrange method to model developed hydrodynamic slugs in conduits Type de document : texte imprimé Auteurs : Guzmán, J. E. V., Auteur ; Zenit, R., Auteur Année de publication : 2011 Article en page(s) : 09 p. Note générale : Fluids engineering Langues : Anglais (eng) Mots-clés : Flow  simulation  Hydrodynamics  Multiphase  flow  Petroleum  industry  Pipe  flow  Pipelines Index. décimale : 620.1 Essais des matériaux. Défauts des matériaux. Protection des matériaux Résumé : Hydrodynamic slugging occurs frequently in nature and in various industrial systems. Under certain circumstances, a mechanistic approach to study such flows is possible and the Euler–Lagrange method may be conveniently implemented. Here, the modeling procedure is illustrated with a simple application to a conduit of a general topographic shape. As an example, the model is adapted to simulate the transient pressure response of an oil-industry-like pipeline configuration. The results are validated with experimental data for short, medium, and long slugs. The model constitutes an extension of previous modeling efforts, and illustrates why the usual flow prediction techniques (based on flow-maps) need to be reinterpreted when long slugs are present in such systems. DEWEY : 620.1 ISSN : 0742-4795 En ligne : http://scitation.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=JFEGA400013 [...] [article] Application of the Euler–Lagrange method to model developed hydrodynamic slugs in conduits [texte imprimé] / Guzmán, J. E. V., Auteur ; Zenit, R., Auteur . - 2011 . - 09 p. Fluids engineering Langues : Anglais (eng) in Transactions of the ASME . Journal of fluids engineering > Vol. 133 N° 4 (Avril 2011) . - 09 p. Mots-clés : Flow  simulation  Hydrodynamics  Multiphase  flow  Petroleum  industry  Pipe  flow  Pipelines Index. décimale : 620.1 Essais des matériaux. Défauts des matériaux. Protection des matériaux Résumé : Hydrodynamic slugging occurs frequently in nature and in various industrial systems. Under certain circumstances, a mechanistic approach to study such flows is possible and the Euler–Lagrange method may be conveniently implemented. Here, the modeling procedure is illustrated with a simple application to a conduit of a general topographic shape. As an example, the model is adapted to simulate the transient pressure response of an oil-industry-like pipeline configuration. The results are validated with experimental data for short, medium, and long slugs. The model constitutes an extension of previous modeling efforts, and illustrates why the usual flow prediction techniques (based on flow-maps) need to be reinterpreted when long slugs are present in such systems. DEWEY : 620.1 ISSN : 0742-4795 En ligne : http://scitation.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=JFEGA400013 [...]

Solid-liquid two-phase flow measurement using an electromagnetically induced signal measurement method / Hiroshi Yamaguchi in Transactions of the ASME . Journal of fluids engineering, Vol. 133 N° 4 (Avril 2011) 

Public ISBD [article]  in Transactions of the ASME . Journal of fluids engineering > Vol. 133 N° 4 (Avril 2011) . - 06 p. Titre : Solid-liquid two-phase flow measurement using an electromagnetically induced signal measurement method Type de document : texte imprimé Auteurs : Hiroshi Yamaguchi, Auteur ; Niu, Xiao-Dong, Auteur ; Nagaoka, Shogo, Auteur Année de publication : 2011 Article en page(s) : 06 p. Note générale : Fluids engineering Langues : Anglais (eng) Mots-clés : Flow  visualisation  Two-phase  flow Index. décimale : 620.1 Essais des matériaux. Défauts des matériaux. Protection des matériaux Résumé : An electromagnetically induced signal measurement method is presented to measure solid-liquid two-phase flows in the present study. The method is validated by comparing visualization results for three flow patterns of “pseudo-homogenous flow,” “heterogeneous flow” and “heterogeneous and sliding-bed flow.” The present method has demonstrated a promising capability of measuring concentration and velocity of solid particles simultaneously with good accuracy. DEWEY : 620.1 ISSN : 0742-4795 En ligne : http://scitation.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=JFEGA400013 [...] [article] Solid-liquid two-phase flow measurement using an electromagnetically induced signal measurement method [texte imprimé] / Hiroshi Yamaguchi, Auteur ; Niu, Xiao-Dong, Auteur ; Nagaoka, Shogo, Auteur . - 2011 . - 06 p. Fluids engineering Langues : Anglais (eng) in Transactions of the ASME . Journal of fluids engineering > Vol. 133 N° 4 (Avril 2011) . - 06 p. Mots-clés : Flow  visualisation  Two-phase  flow Index. décimale : 620.1 Essais des matériaux. Défauts des matériaux. Protection des matériaux Résumé : An electromagnetically induced signal measurement method is presented to measure solid-liquid two-phase flows in the present study. The method is validated by comparing visualization results for three flow patterns of “pseudo-homogenous flow,” “heterogeneous flow” and “heterogeneous and sliding-bed flow.” The present method has demonstrated a promising capability of measuring concentration and velocity of solid particles simultaneously with good accuracy. DEWEY : 620.1 ISSN : 0742-4795 En ligne : http://scitation.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=JFEGA400013 [...]

Frictional loss studies and experimental performance of a new synchronal rotary multiphase pump / Yang, Xu in Transactions of the ASME . Journal of fluids engineering, Vol. 133 N° 4 (Avril 2011) 

Public ISBD [article]  in Transactions of the ASME . Journal of fluids engineering > Vol. 133 N° 4 (Avril 2011) . - 09 p. Titre : Frictional loss studies and experimental performance of a new synchronal rotary multiphase pump Type de document : texte imprimé Auteurs : Yang, Xu, Auteur ; Qu, Zongchang, Auteur ; Wu, Yuyuan, Auteur Année de publication : 2011 Article en page(s) : 09 p. Note générale : Fluids engineering Langues : Anglais (eng) Mots-clés : Blades  Crude  oil  Machine  bearings  Mathematical  analysis  Prototypes  Pumps  Seals  (stoppers)  Shafts  Sliding  friction Index. décimale : 620.1 Essais des matériaux. Défauts des matériaux. Protection des matériaux Résumé : A new synchronal rotary multiphase pump (SRMP) is presented, which is geometrically simple and easy to manufacture. With the rotary cylinder, the frictional losses between the major components of the SRMP are minimized. Its structural design and working principles are introduced. The mathematic models of the frictional losses at various friction-couplings are formulated. Calculations on the frictional losses and mechanical efficiency are performed for a SRMP prototype, too. Experimental works on the prototype in which crude oil is used as working fluids are conducted to validate the functionality of the SRMP and the established models. The calculated results show that the frictional losses in the SRMP are mainly produced by the friction from bearings and seals. The frictional losses caused by the other part of components occupy less than 13% of the total frictional losses. In addition, the theoretical analyses of the various shaft speeds and basic geometrical parameters reveal that the cylinder rotary inertia exercises a negative effect on the friction at the sliding vane sides. Lower shaft speed and smaller eccentricity-cylinder radius ratio are helpful to reduce this effect. In the experiment, the SRMP is operated at shaft speeds of 400, 600 and 800 rpm respectively. The pressure differences are arranged within 0–2.4MPa. The measured values of the shaft consumption powers are shown to be in good agreement with the calculations. These results confirm that the SRMP is suitable for multiphase transportation and has a higher mechanical efficiency. DEWEY : 620.1 ISSN : 0742-4795 En ligne : http://scitation.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=JFEGA400013 [...] [article] Frictional loss studies and experimental performance of a new synchronal rotary multiphase pump [texte imprimé] / Yang, Xu, Auteur ; Qu, Zongchang, Auteur ; Wu, Yuyuan, Auteur . - 2011 . - 09 p. Fluids engineering Langues : Anglais (eng) in Transactions of the ASME . Journal of fluids engineering > Vol. 133 N° 4 (Avril 2011) . - 09 p. Mots-clés : Blades  Crude  oil  Machine  bearings  Mathematical  analysis  Prototypes  Pumps  Seals  (stoppers)  Shafts  Sliding  friction Index. décimale : 620.1 Essais des matériaux. Défauts des matériaux. Protection des matériaux Résumé : A new synchronal rotary multiphase pump (SRMP) is presented, which is geometrically simple and easy to manufacture. With the rotary cylinder, the frictional losses between the major components of the SRMP are minimized. Its structural design and working principles are introduced. The mathematic models of the frictional losses at various friction-couplings are formulated. Calculations on the frictional losses and mechanical efficiency are performed for a SRMP prototype, too. Experimental works on the prototype in which crude oil is used as working fluids are conducted to validate the functionality of the SRMP and the established models. The calculated results show that the frictional losses in the SRMP are mainly produced by the friction from bearings and seals. The frictional losses caused by the other part of components occupy less than 13% of the total frictional losses. In addition, the theoretical analyses of the various shaft speeds and basic geometrical parameters reveal that the cylinder rotary inertia exercises a negative effect on the friction at the sliding vane sides. Lower shaft speed and smaller eccentricity-cylinder radius ratio are helpful to reduce this effect. In the experiment, the SRMP is operated at shaft speeds of 400, 600 and 800 rpm respectively. The pressure differences are arranged within 0–2.4MPa. The measured values of the shaft consumption powers are shown to be in good agreement with the calculations. These results confirm that the SRMP is suitable for multiphase transportation and has a higher mechanical efficiency. DEWEY : 620.1 ISSN : 0742-4795 En ligne : http://scitation.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=JFEGA400013 [...]

Multidimensional modeling of natural gas jet and mixture formation in direct injection spark ignition engines—development and validation of a virtual injector model / Baratta, Mirko in Transactions of the ASME . Journal of fluids engineering, Vol. 133 N° 4 (Avril 2011) 

Public ISBD [article]  in Transactions of the ASME . Journal of fluids engineering > Vol. 133 N° 4 (Avril 2011) . - 14 p. Titre : Multidimensional modeling of natural gas jet and mixture formation in direct injection spark ignition engines—development and validation of a virtual injector model Type de document : texte imprimé Auteurs : Baratta, Mirko, Auteur ; Andrea E. Catania, Auteur ; Pesce, Francesco C., Auteur Année de publication : 2011 Article en page(s) : 14 p. Note générale : Fluids engineering Langues : Anglais (eng) Mots-clés : compressible  flow,  computational  fluid  dynamics,  fuel  systems,  internal  combustion  engines,  jets,  nozzles,  numerical  analysis,  pistons,  schlieren  systems,  shock  waves,  turbulence Index. décimale : 620.1 Essais des matériaux. Défauts des matériaux. Protection des matériaux Résumé : During the last few years, the integration of CFD tools in the internal combustion (IC) engine design process has continually increased, allowing time and cost savings as the need for experimental prototypes has diminished. Numerical analyses of IC engine flows are rather complex from both the conceptual and operational sides. In fact, these flows involve a variety of unsteady phenomena and the right balance between numerical solution accuracy and computational cost should always be reached. The present paper is focused on computational modeling of natural gas (NG) direct injection (DI) processes from a poppet-valve injector into a bowl-shaped combustion chamber. At high injection pressures, the gas efflux from the injector and the mixture formation processes include turbulent and compressible flow features, such as rarefaction waves and shock formation, which are difficult to accurately capture with numerical simulations, particularly when the combustion chamber geometry is complex and the piston and intake/exhaust valve grids are moving. In this paper, a three-dimensional moving grid model of the combustion engine chamber, originally developed by the authors to include simulation of the actual needle lift, has been enhanced by increasing the accuracy in the proximity of the sonic section of the critical valve-seat nozzle, in order to precisely capture the expansion dynamics the methane undergoes inside the injector and immediately downstream from it. The enhanced numerical model was then validated by comparing the numerical results to Schlieren experimental images for gas injection into a constant-volume bomb. Numerical studies were carried out in order to characterize the fuel-jet properties and the evolution of mixture formation for a centrally mounted injector configuration in the case of a pancake-shaped test chamber and the real engine chamber. Finally, the fluid properties calculated by the model in the throat section of the critical nozzle were taken as reference data for developing a new effective virtual injector model, which allows the designer to remove the whole computational domain upstream from the sonic section of the nozzle, keeping the flow properties virtually unchanged there. The virtual injector model outcomes were shown to be in very good agreement with the results of the enhanced complete injector model, substantiating the reliability of the proposed novel approach. DEWEY : 620.1 ISSN : 0742-4795 En ligne : http://scitation.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=JFEGA400013 [...] [article] Multidimensional modeling of natural gas jet and mixture formation in direct injection spark ignition engines—development and validation of a virtual injector model [texte imprimé] / Baratta, Mirko, Auteur ; Andrea E. Catania, Auteur ; Pesce, Francesco C., Auteur . - 2011 . - 14 p. Fluids engineering Langues : Anglais (eng) in Transactions of the ASME . Journal of fluids engineering > Vol. 133 N° 4 (Avril 2011) . - 14 p. Mots-clés : compressible  flow,  computational  fluid  dynamics,  fuel  systems,  internal  combustion  engines,  jets,  nozzles,  numerical  analysis,  pistons,  schlieren  systems,  shock  waves,  turbulence Index. décimale : 620.1 Essais des matériaux. Défauts des matériaux. Protection des matériaux Résumé : During the last few years, the integration of CFD tools in the internal combustion (IC) engine design process has continually increased, allowing time and cost savings as the need for experimental prototypes has diminished. Numerical analyses of IC engine flows are rather complex from both the conceptual and operational sides. In fact, these flows involve a variety of unsteady phenomena and the right balance between numerical solution accuracy and computational cost should always be reached. The present paper is focused on computational modeling of natural gas (NG) direct injection (DI) processes from a poppet-valve injector into a bowl-shaped combustion chamber. At high injection pressures, the gas efflux from the injector and the mixture formation processes include turbulent and compressible flow features, such as rarefaction waves and shock formation, which are difficult to accurately capture with numerical simulations, particularly when the combustion chamber geometry is complex and the piston and intake/exhaust valve grids are moving. In this paper, a three-dimensional moving grid model of the combustion engine chamber, originally developed by the authors to include simulation of the actual needle lift, has been enhanced by increasing the accuracy in the proximity of the sonic section of the critical valve-seat nozzle, in order to precisely capture the expansion dynamics the methane undergoes inside the injector and immediately downstream from it. The enhanced numerical model was then validated by comparing the numerical results to Schlieren experimental images for gas injection into a constant-volume bomb. Numerical studies were carried out in order to characterize the fuel-jet properties and the evolution of mixture formation for a centrally mounted injector configuration in the case of a pancake-shaped test chamber and the real engine chamber. Finally, the fluid properties calculated by the model in the throat section of the critical nozzle were taken as reference data for developing a new effective virtual injector model, which allows the designer to remove the whole computational domain upstream from the sonic section of the nozzle, keeping the flow properties virtually unchanged there. The virtual injector model outcomes were shown to be in very good agreement with the results of the enhanced complete injector model, substantiating the reliability of the proposed novel approach. DEWEY : 620.1 ISSN : 0742-4795 En ligne : http://scitation.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=JFEGA400013 [...]

Theoretical, numerical, and experimental study of the time of flight flowmeter / Gaskin, Ian in Transactions of the ASME . Journal of fluids engineering, Vol. 133 N° 4 (Avril 2011) 

Public ISBD [article]  in Transactions of the ASME . Journal of fluids engineering > Vol. 133 N° 4 (Avril 2011) . - 08 p. Titre : Theoretical, numerical, and experimental study of the time of flight flowmeter Type de document : texte imprimé Auteurs : Gaskin, Ian, Auteur ; Shapiro, Evgeniy, Auteur ; Drikakis, Dimitris, Auteur Année de publication : 2011 Article en page(s) : 08 p. Note générale : Fluids engineering Langues : Anglais (eng) Mots-clés : Flowmeters  Helium  Nitrogen  Pipe  flow Index. décimale : 620.1 Essais des matériaux. Défauts des matériaux. Protection des matériaux Résumé : Time-of-flight flowmeters offer advantages over other flowmeter types since these are less sensitive to the physical properties of the fluid. However, calibration of the flowmeter for a particular working fluid is still required. A flowmeter that does not require re-calibration with different fluids is desirable in many applications. This paper investigates the performance of a device that measures the time of flight of a heat pulse in a gas stream to determine the flow rate in a pipe. A fusion of the theoretical, experimental, and numerical data is used to suggest a gas-independent correlation function between the response time and flow rate. In particular, the numerical data augmented by the theoretical analysis to account for the wire response time is validated against experimental data and used to further enhance the experimental data set. Nitrogen, helium, and tetrafluoroethane (R134a) are investigated, as these gases provide a wide range of physical and thermodynamic properties. Simulated results match the trends of experimental data well and allow good qualitative analysis. The results also show that using detected pulse width information together with the time of flight can yield a 20% reduction in the errors due to gas type than by using time of flight data alone. This gives a relatively gas-independent function over a dynamic range of 1:400. DEWEY : 620.1 ISSN : 0742-4795 En ligne : http://scitation.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=JFEGA400013 [...] [article] Theoretical, numerical, and experimental study of the time of flight flowmeter [texte imprimé] / Gaskin, Ian, Auteur ; Shapiro, Evgeniy, Auteur ; Drikakis, Dimitris, Auteur . - 2011 . - 08 p. Fluids engineering Langues : Anglais (eng) in Transactions of the ASME . Journal of fluids engineering > Vol. 133 N° 4 (Avril 2011) . - 08 p. Mots-clés : Flowmeters  Helium  Nitrogen  Pipe  flow Index. décimale : 620.1 Essais des matériaux. Défauts des matériaux. Protection des matériaux Résumé : Time-of-flight flowmeters offer advantages over other flowmeter types since these are less sensitive to the physical properties of the fluid. However, calibration of the flowmeter for a particular working fluid is still required. A flowmeter that does not require re-calibration with different fluids is desirable in many applications. This paper investigates the performance of a device that measures the time of flight of a heat pulse in a gas stream to determine the flow rate in a pipe. A fusion of the theoretical, experimental, and numerical data is used to suggest a gas-independent correlation function between the response time and flow rate. In particular, the numerical data augmented by the theoretical analysis to account for the wire response time is validated against experimental data and used to further enhance the experimental data set. Nitrogen, helium, and tetrafluoroethane (R134a) are investigated, as these gases provide a wide range of physical and thermodynamic properties. Simulated results match the trends of experimental data well and allow good qualitative analysis. The results also show that using detected pulse width information together with the time of flight can yield a 20% reduction in the errors due to gas type than by using time of flight data alone. This gives a relatively gas-independent function over a dynamic range of 1:400. DEWEY : 620.1 ISSN : 0742-4795 En ligne : http://scitation.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=JFEGA400013 [...]

Uncertainty quantification of turbulence model coefficients via latin hypercube sampling method / Dunn, Matthew C. in Transactions of the ASME . Journal of fluids engineering, Vol. 133 N° 4 (Avril 2011) 

Public ISBD [article]  in Transactions of the ASME . Journal of fluids engineering > Vol. 133 N° 4 (Avril 2011) . - 07 p. Titre : Uncertainty quantification of turbulence model coefficients via latin hypercube sampling method Type de document : texte imprimé Auteurs : Dunn, Matthew C., Auteur ; Shotorban, Babak, Auteur ; Abdelkader Frendi, Auteur Année de publication : 2011 Article en page(s) : 07 p. Note générale : Fluids engineering Langues : Anglais (eng) Mots-clés : Error  analysis  External  flows  Flow  separation  Flow  simulation  Shear  flow  Turbulence Index. décimale : 620.1 Essais des matériaux. Défauts des matériaux. Protection des matériaux Résumé : The article is concerned with the propagation of uncertainties in the values of turbulence model coefficients and parameters in turbulent flows. These coefficients and parameters are obtained through experiments performed on elementary flows, and they are subject to uncertainty. In this work, the widely used k-[eh] turbulence model is considered. It consists of model transport equations for the turbulence kinetic energy and the rate of turbulent dissipation. Both equations involve various model coefficients about which adequate knowledge is assumed known in the form of probability density functions. The study is carried out for a flow over a 2D backward-facing step configuration. The Latin Hypercube Sampling method is employed for the uncertainty quantification purposes as it requires a smaller number of samples compared to the conventional Monte Carlo method. The mean values are reported for the flow output parameters of interest along with their associated uncertainties. The results show that model coefficient variability has significant effects on the streamwise mean velocity in the recirculation region near the reattachment point and turbulence intensity along the free shear layer. The reattachment point location, pressure, and wall shear are also significantly influenced by the uncertainties of the coefficients. DEWEY : 620.1 ISSN : 0742-4795 En ligne : http://scitation.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=JFEGA400013 [...] [article] Uncertainty quantification of turbulence model coefficients via latin hypercube sampling method [texte imprimé] / Dunn, Matthew C., Auteur ; Shotorban, Babak, Auteur ; Abdelkader Frendi, Auteur . - 2011 . - 07 p. Fluids engineering Langues : Anglais (eng) in Transactions of the ASME . Journal of fluids engineering > Vol. 133 N° 4 (Avril 2011) . - 07 p. Mots-clés : Error  analysis  External  flows  Flow  separation  Flow  simulation  Shear  flow  Turbulence Index. décimale : 620.1 Essais des matériaux. Défauts des matériaux. Protection des matériaux Résumé : The article is concerned with the propagation of uncertainties in the values of turbulence model coefficients and parameters in turbulent flows. These coefficients and parameters are obtained through experiments performed on elementary flows, and they are subject to uncertainty. In this work, the widely used k-[eh] turbulence model is considered. It consists of model transport equations for the turbulence kinetic energy and the rate of turbulent dissipation. Both equations involve various model coefficients about which adequate knowledge is assumed known in the form of probability density functions. The study is carried out for a flow over a 2D backward-facing step configuration. The Latin Hypercube Sampling method is employed for the uncertainty quantification purposes as it requires a smaller number of samples compared to the conventional Monte Carlo method. The mean values are reported for the flow output parameters of interest along with their associated uncertainties. The results show that model coefficient variability has significant effects on the streamwise mean velocity in the recirculation region near the reattachment point and turbulence intensity along the free shear layer. The reattachment point location, pressure, and wall shear are also significantly influenced by the uncertainties of the coefficients. DEWEY : 620.1 ISSN : 0742-4795 En ligne : http://scitation.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=JFEGA400013 [...]

The effect of nonuniform viscosity on stagnation point pressure / Norris, Stuart E. in Transactions of the ASME . Journal of fluids engineering, Vol. 133 N° 4 (Avril 2011) 

Public ISBD [article]  in Transactions of the ASME . Journal of fluids engineering > Vol. 133 N° 4 (Avril 2011) . - 04 p. Titre : The effect of nonuniform viscosity on stagnation point pressure Type de document : texte imprimé Auteurs : Norris, Stuart E., Auteur Année de publication : 2011 Article en page(s) : 04 p. Note générale : Fluids engineering Langues : Anglais (eng) Mots-clés : Lubricating  oils  Poiseuille  flow  Stagnation  flow  Turbulence  Viscosity Index. décimale : 620.1 Essais des matériaux. Défauts des matériaux. Protection des matériaux Résumé : For high Reynolds number flows the total pressure remains constant along stream lines. At low Reynolds numbers the total pressure decreases in a global sense due to the actions of viscosity, but it may increase locally in regions such as stagnation points. Previous studies have considered the case of constant viscosity flow. However, gradients in the effective viscosity can occur normal to the wall for the flow of lubricating oils, and for turbulent flows calculated using an eddy viscosity model. In this paper the effect of these viscosity gradients on the stagnation point pressure are examined. DEWEY : 620.1 ISSN : 0742-4795 En ligne : http://scitation.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=JFEGA400013 [...] [article] The effect of nonuniform viscosity on stagnation point pressure [texte imprimé] / Norris, Stuart E., Auteur . - 2011 . - 04 p. Fluids engineering Langues : Anglais (eng) in Transactions of the ASME . Journal of fluids engineering > Vol. 133 N° 4 (Avril 2011) . - 04 p. Mots-clés : Lubricating  oils  Poiseuille  flow  Stagnation  flow  Turbulence  Viscosity Index. décimale : 620.1 Essais des matériaux. Défauts des matériaux. Protection des matériaux Résumé : For high Reynolds number flows the total pressure remains constant along stream lines. At low Reynolds numbers the total pressure decreases in a global sense due to the actions of viscosity, but it may increase locally in regions such as stagnation points. Previous studies have considered the case of constant viscosity flow. However, gradients in the effective viscosity can occur normal to the wall for the flow of lubricating oils, and for turbulent flows calculated using an eddy viscosity model. In this paper the effect of these viscosity gradients on the stagnation point pressure are examined. DEWEY : 620.1 ISSN : 0742-4795 En ligne : http://scitation.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=JFEGA400013 [...]

Drive characteristics of viscous oil film considering temperature effect / Fangwei Xie in Transactions of the ASME . Journal of fluids engineering, Vol. 133 N° 4 (Avril 2011) 

Public ISBD [article]  in Transactions of the ASME . Journal of fluids engineering > Vol. 133 N° 4 (Avril 2011) . - 04 p. Titre : Drive characteristics of viscous oil film considering temperature effect Type de document : texte imprimé Auteurs : Fangwei Xie, Auteur ; Hou, Youfu, Auteur ; Yang, Ping, Auteur Année de publication : 2011 Article en page(s) : 04 p. Note générale : Fluids engineering Langues : Anglais (eng) Mots-clés : Film  flow  Liquid  films  Oils  Rotational  flow  Viscosity Index. décimale : 620.1 Essais des matériaux. Défauts des matériaux. Protection des matériaux Résumé : Taking account of temperature and the effect of pressure difference and inertia force on oil film, the analytic solutions for pressure, radial velocity, and transferred torque were derived. The results show that considering the effect of temperature, the pressure reduces at the same radius and inertia force makes the pressure decrease. Compared with the pressure decrease caused by the inertia force, the radial velocity caused by the pressure difference is very small and can even be neglected. As the rotational velocity difference increases, the transferred torque also increases. Meanwhile, the transferred torque reduces when considering the effect of temperature. DEWEY : 620.1 ISSN : 0742-4795 En ligne : http://scitation.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=JFEGA400013 [...] [article] Drive characteristics of viscous oil film considering temperature effect [texte imprimé] / Fangwei Xie, Auteur ; Hou, Youfu, Auteur ; Yang, Ping, Auteur . - 2011 . - 04 p. Fluids engineering Langues : Anglais (eng) in Transactions of the ASME . Journal of fluids engineering > Vol. 133 N° 4 (Avril 2011) . - 04 p. Mots-clés : Film  flow  Liquid  films  Oils  Rotational  flow  Viscosity Index. décimale : 620.1 Essais des matériaux. Défauts des matériaux. Protection des matériaux Résumé : Taking account of temperature and the effect of pressure difference and inertia force on oil film, the analytic solutions for pressure, radial velocity, and transferred torque were derived. The results show that considering the effect of temperature, the pressure reduces at the same radius and inertia force makes the pressure decrease. Compared with the pressure decrease caused by the inertia force, the radial velocity caused by the pressure difference is very small and can even be neglected. As the rotational velocity difference increases, the transferred torque also increases. Meanwhile, the transferred torque reduces when considering the effect of temperature. DEWEY : 620.1 ISSN : 0742-4795 En ligne : http://scitation.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=JFEGA400013 [...]

Mechanical inhibition of foam formation via a rotating nozzle / Alexander G. Bick in Transactions of the ASME . Journal of fluids engineering, Vol. 133 N° 4 (Avril 2011) 

Public ISBD [article]  in Transactions of the ASME . Journal of fluids engineering > Vol. 133 N° 4 (Avril 2011) . - 03 p. Titre : Mechanical inhibition of foam formation via a rotating nozzle Type de document : texte imprimé Auteurs : Alexander G. Bick, Auteur ; William D. Ristenpart, Auteur ; van Nierop, Ernst A., Auteur Année de publication : 2011 Article en page(s) : 03 p. Note générale : Fluids engineering Langues : Anglais (eng) Mots-clés : Bubbles  Capillarity  Confined  flow  Drops  Foams  Nozzles  Rotational  flow  Two-phase  flow Index. décimale : 620.1 Essais des matériaux. Défauts des matériaux. Protection des matériaux Résumé : We recently discovered that bubble formation can be substantially prevented when an aqueous solution is sprayed into a bath of the same solution provided that any two consecutive drops impacting the same surface location do so with a time interval greater than the capillary relaxation time. Building on this observation, here we report a mechanical means of preventing foam formation during liquid addition: the nozzle delivering the liquid is rotated sufficiently rapidly so that no two successive drops impact the interface at the same location. Foam formation is reduced by as much as 95% without any chemical anti-foaming agents. DEWEY : 620.1 ISSN : 0742-4795 En ligne : http://scitation.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=JFEGA400013 [...] [article] Mechanical inhibition of foam formation via a rotating nozzle [texte imprimé] / Alexander G. Bick, Auteur ; William D. Ristenpart, Auteur ; van Nierop, Ernst A., Auteur . - 2011 . - 03 p. Fluids engineering Langues : Anglais (eng) in Transactions of the ASME . Journal of fluids engineering > Vol. 133 N° 4 (Avril 2011) . - 03 p. Mots-clés : Bubbles  Capillarity  Confined  flow  Drops  Foams  Nozzles  Rotational  flow  Two-phase  flow Index. décimale : 620.1 Essais des matériaux. Défauts des matériaux. Protection des matériaux Résumé : We recently discovered that bubble formation can be substantially prevented when an aqueous solution is sprayed into a bath of the same solution provided that any two consecutive drops impacting the same surface location do so with a time interval greater than the capillary relaxation time. Building on this observation, here we report a mechanical means of preventing foam formation during liquid addition: the nozzle delivering the liquid is rotated sufficiently rapidly so that no two successive drops impact the interface at the same location. Foam formation is reduced by as much as 95% without any chemical anti-foaming agents. DEWEY : 620.1 ISSN : 0742-4795 En ligne : http://scitation.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=JFEGA400013 [...]

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