Dépouillements

Reliable and accurate prediction of three-dimensional separation in asymmetric diffusers using large-Eddy simulation / Hayder Schneider in Transactions of the ASME . Journal of fluids engineering, Vol. 132 N° 3 (Mars 2010) 

Public ISBD [article]  in Transactions of the ASME . Journal of fluids engineering > Vol. 132 N° 3 (Mars 2010) . - 07 p. Titre : Reliable and accurate prediction of three-dimensional separation in asymmetric diffusers using large-Eddy simulation Type de document : texte imprimé Auteurs : Hayder Schneider, Auteur ; Dominic von Terzi, Auteur ; Hans-Jörg Bauer, Auteur Année de publication : 2010 Article en page(s) : 07 p. Note générale : fluids engineering Langues : Anglais (eng) Mots-clés : asymmetric  three-dimensional  diffusers;  large-eddy  simulations Résumé : Large-eddy simulations (LES) and Reynolds-averaged Navier–Stokes (RANS) calculations of the flow in two asymmetric three-dimensional diffusers were performed. The setup was chosen to match an existing experiment with separation. Both diffusers possess the same expansion ratio but differ in performance. The aim of the present study is to find the least expensive method to reliably and with reasonable accuracy account for the impact of the change in geometry. RANS calculations failed to predict both the extent and location of the separation. In contrast, LES with wall-functions delivered results within the accuracy of the experimental data. DEWEY : 620.1 ISSN : 0098-2202 En ligne : http://fluidsengineering.asmedigitalcollection.asme.org/issue.aspx?journalid=122 [...] [article] Reliable and accurate prediction of three-dimensional separation in asymmetric diffusers using large-Eddy simulation [texte imprimé] / Hayder Schneider, Auteur ; Dominic von Terzi, Auteur ; Hans-Jörg Bauer, Auteur . - 2010 . - 07 p. fluids engineering Langues : Anglais (eng) in Transactions of the ASME . Journal of fluids engineering > Vol. 132 N° 3 (Mars 2010) . - 07 p. Mots-clés : asymmetric  three-dimensional  diffusers;  large-eddy  simulations Résumé : Large-eddy simulations (LES) and Reynolds-averaged Navier–Stokes (RANS) calculations of the flow in two asymmetric three-dimensional diffusers were performed. The setup was chosen to match an existing experiment with separation. Both diffusers possess the same expansion ratio but differ in performance. The aim of the present study is to find the least expensive method to reliably and with reasonable accuracy account for the impact of the change in geometry. RANS calculations failed to predict both the extent and location of the separation. In contrast, LES with wall-functions delivered results within the accuracy of the experimental data. DEWEY : 620.1 ISSN : 0098-2202 En ligne : http://fluidsengineering.asmedigitalcollection.asme.org/issue.aspx?journalid=122 [...]

The effects of fins on the intermediate wake of a submarine model / Jiménez, Juan M. in Transactions of the ASME . Journal of fluids engineering, Vol. 132 N° 3 (Mars 2010) 

Public ISBD [article]  in Transactions of the ASME . Journal of fluids engineering > Vol. 132 N° 3 (Mars 2010) . - 07 p. Titre : The effects of fins on the intermediate wake of a submarine model Type de document : texte imprimé Auteurs : Jiménez, Juan M., Auteur ; Ryan T. Reynolds, Auteur ; Smits, Alexander J., Auteur Année de publication : 2010 Article en page(s) : 07 p. Note générale : fluids engineering Langues : Anglais (eng) Résumé : Results are presented on the behavior of the turbulent wake behind a submarine model for a range of Reynolds numbers based on the model length between 0.49×106 and 1.8×106, for test locations between 3 and 9 diameters downstream of the stern. The shape of the model emulates an idealized submarine, and tests were performed with and without stern fins. In the absence of fins, the velocity profile in planes away from the influence of the sail rapidly becomes self-similar and is well described by a function of exponentials. The fins create defects in the velocity profiles in the outer region of the wake, while yielding higher values of turbulence at locations corresponding to the tips of the fins. Measurements conducted in planes away from the midline plane show that the velocity profiles remain self-similar, while the shear stress profiles clearly show the effects of the necklace vortices trailing from the base of the fins. DEWEY : 620.1 ISSN : 0098-2202 En ligne : http://fluidsengineering.asmedigitalcollection.asme.org/issue.aspx?journalid=122 [...] [article] The effects of fins on the intermediate wake of a submarine model [texte imprimé] / Jiménez, Juan M., Auteur ; Ryan T. Reynolds, Auteur ; Smits, Alexander J., Auteur . - 2010 . - 07 p. fluids engineering Langues : Anglais (eng) in Transactions of the ASME . Journal of fluids engineering > Vol. 132 N° 3 (Mars 2010) . - 07 p. Résumé : Results are presented on the behavior of the turbulent wake behind a submarine model for a range of Reynolds numbers based on the model length between 0.49×106 and 1.8×106, for test locations between 3 and 9 diameters downstream of the stern. The shape of the model emulates an idealized submarine, and tests were performed with and without stern fins. In the absence of fins, the velocity profile in planes away from the influence of the sail rapidly becomes self-similar and is well described by a function of exponentials. The fins create defects in the velocity profiles in the outer region of the wake, while yielding higher values of turbulence at locations corresponding to the tips of the fins. Measurements conducted in planes away from the midline plane show that the velocity profiles remain self-similar, while the shear stress profiles clearly show the effects of the necklace vortices trailing from the base of the fins. DEWEY : 620.1 ISSN : 0098-2202 En ligne : http://fluidsengineering.asmedigitalcollection.asme.org/issue.aspx?journalid=122 [...]

Flow force analysis of a variable force solenoid valve for automatic transmissions / Gee Soo Lee in Transactions of the ASME . Journal of fluids engineering, Vol. 132 N° 3 (Mars 2010) 

Public ISBD [article]  in Transactions of the ASME . Journal of fluids engineering > Vol. 132 N° 3 (Mars 2010) . - 07 p. Titre : Flow force analysis of a variable force solenoid valve for automatic transmissions Type de document : texte imprimé Auteurs : Gee Soo Lee, Auteur ; Hyung Jin Sung, Auteur ; Hyun Chul Kim, Auteur Année de publication : 2010 Article en page(s) : 07 p. Note générale : fluids engineering Langues : Anglais (eng) Mots-clés : flow  dynamic  behavior;  variable  force  solenoid;  three-dimensional  numerical  simulations Résumé : Three-dimensional numerical simulations were carried out to investigate the flow dynamic behavior and pressure characteristics of a variable force solenoid (VFS) valve used in automatic transmissions. To visualize the dynamic movement of the spool, a moving mesh with dynamic layering meshes for varying boundary conditions was employed. Relevant experiment was performed to validate the simulations. The VFS valve was characterized by determining the variation in the equivalent orifice area with the spool displacement. The pressure sensitivity was found to be precisely controlled by the relation between the depth and the area of the notch in the range of the characteristic length of the valve. The results of model C, which takes into account both seal leakage and notches, indicate that there are linear pressure sensitivities in the range of the valve overlap and that there are smooth pressure control characteristics in the range of the two notches. The VFS valve with a spool was shown to have an unavoidable and unique hysteresis, which is caused by the nonlinear electromagnetic forces at the end of strokes of the spool and by the friction forces in the valve overlap. The effects of varying the oil temperature on the pressure sensitivity curves and the seal leakage flow rates were also examined. DEWEY : 620.1 ISSN : 0098-2202 En ligne : http://fluidsengineering.asmedigitalcollection.asme.org/issue.aspx?journalid=122 [...] [article] Flow force analysis of a variable force solenoid valve for automatic transmissions [texte imprimé] / Gee Soo Lee, Auteur ; Hyung Jin Sung, Auteur ; Hyun Chul Kim, Auteur . - 2010 . - 07 p. fluids engineering Langues : Anglais (eng) in Transactions of the ASME . Journal of fluids engineering > Vol. 132 N° 3 (Mars 2010) . - 07 p. Mots-clés : flow  dynamic  behavior;  variable  force  solenoid;  three-dimensional  numerical  simulations Résumé : Three-dimensional numerical simulations were carried out to investigate the flow dynamic behavior and pressure characteristics of a variable force solenoid (VFS) valve used in automatic transmissions. To visualize the dynamic movement of the spool, a moving mesh with dynamic layering meshes for varying boundary conditions was employed. Relevant experiment was performed to validate the simulations. The VFS valve was characterized by determining the variation in the equivalent orifice area with the spool displacement. The pressure sensitivity was found to be precisely controlled by the relation between the depth and the area of the notch in the range of the characteristic length of the valve. The results of model C, which takes into account both seal leakage and notches, indicate that there are linear pressure sensitivities in the range of the valve overlap and that there are smooth pressure control characteristics in the range of the two notches. The VFS valve with a spool was shown to have an unavoidable and unique hysteresis, which is caused by the nonlinear electromagnetic forces at the end of strokes of the spool and by the friction forces in the valve overlap. The effects of varying the oil temperature on the pressure sensitivity curves and the seal leakage flow rates were also examined. DEWEY : 620.1 ISSN : 0098-2202 En ligne : http://fluidsengineering.asmedigitalcollection.asme.org/issue.aspx?journalid=122 [...]

Parametric design of a waterjet pump by means of inverse design, CFD calculations and experimental analyses / Duccio Bonaiuti in Transactions of the ASME . Journal of fluids engineering, Vol. 132 N° 3 (Mars 2010) 

Public ISBD [article]  in Transactions of the ASME . Journal of fluids engineering > Vol. 132 N° 3 (Mars 2010) . - 15 p. Titre : Parametric design of a waterjet pump by means of inverse design, CFD calculations and experimental analyses Type de document : texte imprimé Auteurs : Duccio Bonaiuti, Auteur ; Mehrdad Zangeneh, Auteur ; Reima Aartojarvi, Auteur Année de publication : 2010 Article en page(s) : 15 p. Note générale : fluids engineering Langues : Anglais (eng) Mots-clés : pressure;  flow  (dynamics);  suction;  impellers;  cavitation;  diffusers;  computational  fluid  dynamics;  design;  pumps;  blades Résumé : The present paper describes the parametric design of a mixed-flow water-jet pump. The pump impeller and diffuser geometries were parameterized by means of an inverse design method, while CFD analyses were performed to assess the hydrodynamic and suction performance of the different design configurations that were investigated. An initial pump design was first generated and used as baseline for the parametric study. The effect of several design parameters was then analyzed in order to determine their effect on the pump performance. The use of a blade parameterization, based on inverse design, led to a major advantage in this study, because the three-dimensional blade shape is described by means of hydrodynamic parameters, such as blade loading, which has a direct impact on the hydrodynamic flow field. On the basis of this study, an optimal configuration was designed with the aim of maximizing the pump suction performance, while at the same time, guaranteeing a high level of hydrodynamic efficiency, together with the required mechanical and vibrational constraints. The final design was experimentally tested, and the good agreement between numerical predictions and experimental results validated the design process. This paper highlights the contrasting requirements in the pump design in order to achieve high hydrodynamic efficiency or good cavitation performance. The parametric study allowed us to determine design guidelines in order to find the optimal compromise in the pump design, in cases where both a high level of efficiency and suction performance must simultaneously be achieved. The design know-how developed in this study is based on flow field analyses and on hydrodynamic design parameters. It has therefore a general validity and can be used for similar design applications. DEWEY : 620.1 ISSN : 0098-2202 En ligne : http://fluidsengineering.asmedigitalcollection.asme.org/issue.aspx?journalid=122 [...] [article] Parametric design of a waterjet pump by means of inverse design, CFD calculations and experimental analyses [texte imprimé] / Duccio Bonaiuti, Auteur ; Mehrdad Zangeneh, Auteur ; Reima Aartojarvi, Auteur . - 2010 . - 15 p. fluids engineering Langues : Anglais (eng) in Transactions of the ASME . Journal of fluids engineering > Vol. 132 N° 3 (Mars 2010) . - 15 p. Mots-clés : pressure;  flow  (dynamics);  suction;  impellers;  cavitation;  diffusers;  computational  fluid  dynamics;  design;  pumps;  blades Résumé : The present paper describes the parametric design of a mixed-flow water-jet pump. The pump impeller and diffuser geometries were parameterized by means of an inverse design method, while CFD analyses were performed to assess the hydrodynamic and suction performance of the different design configurations that were investigated. An initial pump design was first generated and used as baseline for the parametric study. The effect of several design parameters was then analyzed in order to determine their effect on the pump performance. The use of a blade parameterization, based on inverse design, led to a major advantage in this study, because the three-dimensional blade shape is described by means of hydrodynamic parameters, such as blade loading, which has a direct impact on the hydrodynamic flow field. On the basis of this study, an optimal configuration was designed with the aim of maximizing the pump suction performance, while at the same time, guaranteeing a high level of hydrodynamic efficiency, together with the required mechanical and vibrational constraints. The final design was experimentally tested, and the good agreement between numerical predictions and experimental results validated the design process. This paper highlights the contrasting requirements in the pump design in order to achieve high hydrodynamic efficiency or good cavitation performance. The parametric study allowed us to determine design guidelines in order to find the optimal compromise in the pump design, in cases where both a high level of efficiency and suction performance must simultaneously be achieved. The design know-how developed in this study is based on flow field analyses and on hydrodynamic design parameters. It has therefore a general validity and can be used for similar design applications. DEWEY : 620.1 ISSN : 0098-2202 En ligne : http://fluidsengineering.asmedigitalcollection.asme.org/issue.aspx?journalid=122 [...]

The linear stability analysis of the lamb–oseen vortex in a finite-length pipe / Wang, S. in Transactions of the ASME . Journal of fluids engineering, Vol. 132 N° 3 (Mars 2010) 

Public ISBD [article]  in Transactions of the ASME . Journal of fluids engineering > Vol. 132 N° 3 (Mars 2010) . - 13 p. Titre : The linear stability analysis of the lamb–oseen vortex in a finite-length pipe Type de document : texte imprimé Auteurs : Wang, S., Auteur ; S. Taylor, Auteur ; K. Ku Akil, Auteur Année de publication : 2010 Article en page(s) : 13 p. Note générale : fluids engineering Langues : Anglais (eng) Résumé : This article extends the perturbation method introduced by (2008, “A Novel Method for Analyzing the Global Stability of Inviscid Columnar Swirling Flow in a Finite Pipe,” Phys. Fluids, 20(7), p. 074101) to determine the global stability of a swirling flow in a straight circular pipe with specified inlet and outlet boundary conditions. To accurately compute the flow stability characteristics, a general procedure to treat the complexity arising from high-order terms is developed. It extends the previous fourth-order method to an eighth-order method. The technique is first applied to the benchmark case of a solid-body rotation flow with a uniform axial speed. It is demonstrated that the eighth-order method is sufficient to construct the growth rate curve between the first and second critical swirls of this flow. Note that this range of swirl is crucial for the study of the vortex breakdown phenomenon since the base flow is unstable and starts the initial stage of transition to a breakdown state. The method is then applied to the Lamb–Oseen vortex to construct the growth rate curve between the first and second critical swirls of this flow. Calculated results are compared with the growth rate curve computed from direct numerical simulations and an overall agreement between the two computations is found. This demonstrates that the and (1996, “On the Stability of an Axisymmetric Rotating Flow in a Pipe,” Phys. Fluids, 8(4), pp. 1007–1076) instability mechanism captures quantitatively the initial growth of disturbance, which eventually evolves into a breakdown state. DEWEY : 620.1 ISSN : 0098-2202 En ligne : http://fluidsengineering.asmedigitalcollection.asme.org/issue.aspx?journalid=122 [...] [article] The linear stability analysis of the lamb–oseen vortex in a finite-length pipe [texte imprimé] / Wang, S., Auteur ; S. Taylor, Auteur ; K. Ku Akil, Auteur . - 2010 . - 13 p. fluids engineering Langues : Anglais (eng) in Transactions of the ASME . Journal of fluids engineering > Vol. 132 N° 3 (Mars 2010) . - 13 p. Résumé : This article extends the perturbation method introduced by (2008, “A Novel Method for Analyzing the Global Stability of Inviscid Columnar Swirling Flow in a Finite Pipe,” Phys. Fluids, 20(7), p. 074101) to determine the global stability of a swirling flow in a straight circular pipe with specified inlet and outlet boundary conditions. To accurately compute the flow stability characteristics, a general procedure to treat the complexity arising from high-order terms is developed. It extends the previous fourth-order method to an eighth-order method. The technique is first applied to the benchmark case of a solid-body rotation flow with a uniform axial speed. It is demonstrated that the eighth-order method is sufficient to construct the growth rate curve between the first and second critical swirls of this flow. Note that this range of swirl is crucial for the study of the vortex breakdown phenomenon since the base flow is unstable and starts the initial stage of transition to a breakdown state. The method is then applied to the Lamb–Oseen vortex to construct the growth rate curve between the first and second critical swirls of this flow. Calculated results are compared with the growth rate curve computed from direct numerical simulations and an overall agreement between the two computations is found. This demonstrates that the and (1996, “On the Stability of an Axisymmetric Rotating Flow in a Pipe,” Phys. Fluids, 8(4), pp. 1007–1076) instability mechanism captures quantitatively the initial growth of disturbance, which eventually evolves into a breakdown state. DEWEY : 620.1 ISSN : 0098-2202 En ligne : http://fluidsengineering.asmedigitalcollection.asme.org/issue.aspx?journalid=122 [...]

Performance of a novel rotating gas-liquid separator / G. P. Willems in Transactions of the ASME . Journal of fluids engineering, Vol. 132 N° 3 (Mars 2010) 

Public ISBD [article]  in Transactions of the ASME . Journal of fluids engineering > Vol. 132 N° 3 (Mars 2010) . - 11 p. Titre : Performance of a novel rotating gas-liquid separator Type de document : texte imprimé Auteurs : G. P. Willems, Auteur ; J. P. Kroes, Auteur ; M. Golombok, Auteur Année de publication : 2010 Article en page(s) : 11 p. Note générale : fluids engineering Langues : Anglais (eng) Résumé : A novel gas separation process makes use of a rotating phase separator to separate micron-sized droplets from a gas stream. Based on an industrial scale design, a water/air separator is constructed and tested. The first experiment concerns the drainage of large fractions of separated liquid. During operation, drainage is observed via windows and a descriptive model is formulated. Because of the major influence on overall separation efficiency, liquid drainage is a key issue in the separator design. The second experiment comprises a droplet collection efficiency measurement using micron-sized droplets dispersed within the airstream. The separation efficiency of fine droplet removal is measured. This is an important factor in reducing capital costs. DEWEY : 620.1 ISSN : 0098-2202 En ligne : http://fluidsengineering.asmedigitalcollection.asme.org/issue.aspx?journalid=122 [...] [article] Performance of a novel rotating gas-liquid separator [texte imprimé] / G. P. Willems, Auteur ; J. P. Kroes, Auteur ; M. Golombok, Auteur . - 2010 . - 11 p. fluids engineering Langues : Anglais (eng) in Transactions of the ASME . Journal of fluids engineering > Vol. 132 N° 3 (Mars 2010) . - 11 p. Résumé : A novel gas separation process makes use of a rotating phase separator to separate micron-sized droplets from a gas stream. Based on an industrial scale design, a water/air separator is constructed and tested. The first experiment concerns the drainage of large fractions of separated liquid. During operation, drainage is observed via windows and a descriptive model is formulated. Because of the major influence on overall separation efficiency, liquid drainage is a key issue in the separator design. The second experiment comprises a droplet collection efficiency measurement using micron-sized droplets dispersed within the airstream. The separation efficiency of fine droplet removal is measured. This is an important factor in reducing capital costs. DEWEY : 620.1 ISSN : 0098-2202 En ligne : http://fluidsengineering.asmedigitalcollection.asme.org/issue.aspx?journalid=122 [...]

Asymptotic generalizations of the Lockhart–Martinelli method for two phase flows / Y. S. Muzychka in Transactions of the ASME . Journal of fluids engineering, Vol. 132 N° 3 (Mars 2010) 

Public ISBD [article]  in Transactions of the ASME . Journal of fluids engineering > Vol. 132 N° 3 (Mars 2010) . - 12 p. Titre : Asymptotic generalizations of the Lockhart–Martinelli method for two phase flows Type de document : texte imprimé Auteurs : Y. S. Muzychka, Auteur ; M. M. Awad, Auteur Année de publication : 2010 Article en page(s) : 12 p. Note générale : fluids engineering Langues : Anglais (eng) Résumé : The (1949, “Proposed Correlation of Data for Isothermal Two Phase Flow, Two Component Flow in Pipes,” Chem. Eng. Prog., 45, pp. 39–48) method for predicting two phase flow pressure drop is examined from the point of view of asymptotic modeling. Comparisons are made with the Lockhart–Martinelli method, the (1967, “A Theoretical Basis for the Lockhart-Martinelli Correlation for Two Phase Flow,” Int. J. Heat Mass Transfer, 10, pp. 1767–1778) method, and the (1969, One Dimensional Two Phase Flow, McGraw-Hill, New York) method. An alternative approach for predicting two phase flow pressure drop is developed using superposition of three pressure gradients: single phase liquid, single phase gas, and interfacial pressure drop. This new approach allows for the interfacial pressure drop to be easily modeled for each type of flow regime such as bubbly, mist, churn, plug, stratified, and annular, or based on the classical laminar-laminar, turbulent-turbulent, laminar-turbulent, and turbulent-laminar flow regimes proposed by Lockhart and Martinelli. DEWEY : 620.1 ISSN : 0098-2202 En ligne : http://fluidsengineering.asmedigitalcollection.asme.org/issue.aspx?journalid=122 [...] [article] Asymptotic generalizations of the Lockhart–Martinelli method for two phase flows [texte imprimé] / Y. S. Muzychka, Auteur ; M. M. Awad, Auteur . - 2010 . - 12 p. fluids engineering Langues : Anglais (eng) in Transactions of the ASME . Journal of fluids engineering > Vol. 132 N° 3 (Mars 2010) . - 12 p. Résumé : The (1949, “Proposed Correlation of Data for Isothermal Two Phase Flow, Two Component Flow in Pipes,” Chem. Eng. Prog., 45, pp. 39–48) method for predicting two phase flow pressure drop is examined from the point of view of asymptotic modeling. Comparisons are made with the Lockhart–Martinelli method, the (1967, “A Theoretical Basis for the Lockhart-Martinelli Correlation for Two Phase Flow,” Int. J. Heat Mass Transfer, 10, pp. 1767–1778) method, and the (1969, One Dimensional Two Phase Flow, McGraw-Hill, New York) method. An alternative approach for predicting two phase flow pressure drop is developed using superposition of three pressure gradients: single phase liquid, single phase gas, and interfacial pressure drop. This new approach allows for the interfacial pressure drop to be easily modeled for each type of flow regime such as bubbly, mist, churn, plug, stratified, and annular, or based on the classical laminar-laminar, turbulent-turbulent, laminar-turbulent, and turbulent-laminar flow regimes proposed by Lockhart and Martinelli. DEWEY : 620.1 ISSN : 0098-2202 En ligne : http://fluidsengineering.asmedigitalcollection.asme.org/issue.aspx?journalid=122 [...]

A novel 2D incompressible viscous inverse design method for internal flows using flexible string algorithm / Mahdi Nili-Ahmadabadi in Transactions of the ASME . Journal of fluids engineering, Vol. 132 N° 3 (Mars 2010) 

Public ISBD [article]  in Transactions of the ASME . Journal of fluids engineering > Vol. 132 N° 3 (Mars 2010) . - 10 p. Titre : A novel 2D incompressible viscous inverse design method for internal flows using flexible string algorithm Type de document : texte imprimé Auteurs : Mahdi Nili-Ahmadabadi, Auteur ; Ali Hajilouy-Benisi, Auteur ; Farhad Ghadak, Auteur Année de publication : 2010 Article en page(s) : 10 p. Note générale : fluids engineering Langues : Anglais (eng) Mots-clés : pressure;  flow  (dynamics);  separation  (technology);  string;  diffusers;  internal  flow;  algorithms;  design;  design  methodology;  ducts;  equations;  shapes Résumé : In this investigation, the flexible string algorithm (FSA ), used before for inverse design of subsonic and supersonic ducts in compressible flows with and without normal shock, is developed and applied for inverse design of 2D incompressible viscous internal flow with and without separation. In the proposed method, the duct wall shape is changed under an algorithm based on deformation of a virtual flexible string in flow. At each modification step, the difference between current and target wall pressure distributions is applied to the string. The method is an iterative inverse design method and utilizes the analysis code for the flow field solution as a black-box. Some validation test cases and design examples are presented here, which show the robustness and flexibility of the method in handling complex geometries. In cases with separated flow pressure distribution, a unique solution for inverse design problem does not exist. The design algorithm is a physical and quick converging approach and can efficiently utilize commercial flow analysis software. DEWEY : 620.1 ISSN : 0098-2202 En ligne : http://fluidsengineering.asmedigitalcollection.asme.org/Issue.aspx?issueID=27411 [...] [article] A novel 2D incompressible viscous inverse design method for internal flows using flexible string algorithm [texte imprimé] / Mahdi Nili-Ahmadabadi, Auteur ; Ali Hajilouy-Benisi, Auteur ; Farhad Ghadak, Auteur . - 2010 . - 10 p. fluids engineering Langues : Anglais (eng) in Transactions of the ASME . Journal of fluids engineering > Vol. 132 N° 3 (Mars 2010) . - 10 p. Mots-clés : pressure;  flow  (dynamics);  separation  (technology);  string;  diffusers;  internal  flow;  algorithms;  design;  design  methodology;  ducts;  equations;  shapes Résumé : In this investigation, the flexible string algorithm (FSA ), used before for inverse design of subsonic and supersonic ducts in compressible flows with and without normal shock, is developed and applied for inverse design of 2D incompressible viscous internal flow with and without separation. In the proposed method, the duct wall shape is changed under an algorithm based on deformation of a virtual flexible string in flow. At each modification step, the difference between current and target wall pressure distributions is applied to the string. The method is an iterative inverse design method and utilizes the analysis code for the flow field solution as a black-box. Some validation test cases and design examples are presented here, which show the robustness and flexibility of the method in handling complex geometries. In cases with separated flow pressure distribution, a unique solution for inverse design problem does not exist. The design algorithm is a physical and quick converging approach and can efficiently utilize commercial flow analysis software. DEWEY : 620.1 ISSN : 0098-2202 En ligne : http://fluidsengineering.asmedigitalcollection.asme.org/Issue.aspx?issueID=27411 [...]

Development length requirements for fully developed laminar pipe flow of yield stress fluids / R. J. Poole in Transactions of the ASME . Journal of fluids engineering, Vol. 132 N° 3 (Mars 2010) 

Public ISBD [article]  in Transactions of the ASME . Journal of fluids engineering > Vol. 132 N° 3 (Mars 2010) . - 04 p. Titre : Development length requirements for fully developed laminar pipe flow of yield stress fluids Type de document : texte imprimé Auteurs : R. J. Poole, Auteur ; R. P. Chhabra, Auteur Année de publication : 2010 Article en page(s) : 04 p. Note générale : fluids engineering Langues : Anglais (eng) Résumé : In this technical brief, we report the results of a systematic numerical investigation of developing laminar pipe flow of yield stress fluids, obeying models of the Bingham-type. We are able to show that using a suitable choice of the Reynolds number allows, for high Reynolds number values at least, the development length to collapse to the Newtonian correlation. On the other hand, the development length remains a weak, nonmonotonic, function of the Bingham number at small values of the Reynolds number (Re≤40). DEWEY : 620.1 ISSN : 0098-2202 En ligne : http://fluidsengineering.asmedigitalcollection.asme.org/Issue.aspx?issueID=27411 [...] [article] Development length requirements for fully developed laminar pipe flow of yield stress fluids [texte imprimé] / R. J. Poole, Auteur ; R. P. Chhabra, Auteur . - 2010 . - 04 p. fluids engineering Langues : Anglais (eng) in Transactions of the ASME . Journal of fluids engineering > Vol. 132 N° 3 (Mars 2010) . - 04 p. Résumé : In this technical brief, we report the results of a systematic numerical investigation of developing laminar pipe flow of yield stress fluids, obeying models of the Bingham-type. We are able to show that using a suitable choice of the Reynolds number allows, for high Reynolds number values at least, the development length to collapse to the Newtonian correlation. On the other hand, the development length remains a weak, nonmonotonic, function of the Bingham number at small values of the Reynolds number (Re≤40). DEWEY : 620.1 ISSN : 0098-2202 En ligne : http://fluidsengineering.asmedigitalcollection.asme.org/Issue.aspx?issueID=27411 [...]

Adjustment of aerodynamic-compensation characteristics of a pitot tube by rear-body shape manipulation / Jehanzeb Masud in Transactions of the ASME . Journal of fluids engineering, Vol. 132 N° 3 (Mars 2010) 

Public ISBD [article]  in Transactions of the ASME . Journal of fluids engineering > Vol. 132 N° 3 (Mars 2010) . - 06 p. Titre : Adjustment of aerodynamic-compensation characteristics of a pitot tube by rear-body shape manipulation Type de document : texte imprimé Auteurs : Jehanzeb Masud, Auteur ; Farooq bin Akram, Auteur Année de publication : 2010 Article en page(s) : 06 p. Note générale : fluids engineering Langues : Anglais (eng) Résumé : In this paper we present a methodology for adjustment of subsonic compensation characteristics of an aerodynamic-compensation Pitot tube. This methodology is based on manipulation of a Pitot tube profile (shape) downstream of the static pressure port such that its subsonic characteristics are modified while the supersonic characteristics remain unchanged. Due to this “rear-body” shape adjustment, complete redesign of a developed or in service Pitot tube is not required. We have used computational fluid dynamics tools in the analysis and design refinement of a Pitot tube by rear-body shape adjustment. The complete Mach number regime (M<2) has been computationally analyzed for three different rear-body profiles. The results of our study indicate that significant variation in subsonic compensation characteristics of a Pitot tube is possible by this method. DEWEY : 620.1 ISSN : 0098-2202 En ligne : http://fluidsengineering.asmedigitalcollection.asme.org/Issue.aspx?issueID=27411 [...] [article] Adjustment of aerodynamic-compensation characteristics of a pitot tube by rear-body shape manipulation [texte imprimé] / Jehanzeb Masud, Auteur ; Farooq bin Akram, Auteur . - 2010 . - 06 p. fluids engineering Langues : Anglais (eng) in Transactions of the ASME . Journal of fluids engineering > Vol. 132 N° 3 (Mars 2010) . - 06 p. Résumé : In this paper we present a methodology for adjustment of subsonic compensation characteristics of an aerodynamic-compensation Pitot tube. This methodology is based on manipulation of a Pitot tube profile (shape) downstream of the static pressure port such that its subsonic characteristics are modified while the supersonic characteristics remain unchanged. Due to this “rear-body” shape adjustment, complete redesign of a developed or in service Pitot tube is not required. We have used computational fluid dynamics tools in the analysis and design refinement of a Pitot tube by rear-body shape adjustment. The complete Mach number regime (M<2) has been computationally analyzed for three different rear-body profiles. The results of our study indicate that significant variation in subsonic compensation characteristics of a Pitot tube is possible by this method. DEWEY : 620.1 ISSN : 0098-2202 En ligne : http://fluidsengineering.asmedigitalcollection.asme.org/Issue.aspx?issueID=27411 [...]

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