Documents disponibles écrits par cet auteur

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 [...]

A method to generate propulsor side forces / Huyer, Stephen A. in Transactions of the ASME . Journal of fluids engineering, Vol. 132 N° 2 (Fevrier 2010) 

Public ISBD [article]  in Transactions of the ASME . Journal of fluids engineering > Vol. 132 N° 2 (Fevrier 2010) . - 09 p. Titre : A method to generate propulsor side forces Type de document : texte imprimé Auteurs : Huyer, Stephen A., Auteur ; Dropkin, Amanda, Auteur ; James Dick, Auteur Année de publication : 2010 Article en page(s) : 09 p. Note générale : fluids engineering Langues : Anglais (eng) Mots-clés : generate  vehicle;  preswirl  propulsor;  upstream  stator;  downstream  rotor Résumé : A computational study was performed to investigate a method to generate vehicle maneuvering forces from a propulsor alone. A ducted, preswirl propulsor was configured with an upstream stator row and downstream rotor. During normal operation, the upstream stator blades are all situated at the same pitch angle and preswirl the flow into the propulsor while generating a roll moment to counter the moment produced by the rotor. By varying the pitch angles of the stator blade about the circumference, it is possible to both generate a mean stator side force and subsequently vary the axial velocity and swirl that is ingested into the propulsor. The rotor then generates a side force in response to the inflow. Both potential flow and fully viscous 3D Reynolds averaged Navier–Stokes (RANS) computations were used to predict the stator forces, velocity field, and rotor response. Potential flow methods were used for initial examination of a wide variety of stator configurations. The most promising were then modeled using RANS. The RANS inflow was then computed and used as velocity boundary conditions during rotor blade design using potential flow methods. Blade parameters including blade number, rake, skew, and a combination of the two were varied to characterize their effects. RANS was used to then validate the final propulsor design. Computations demonstrated that total side force coefficients on the order of 0.1 and moment coefficients about the stator leading edge of 0.066 could be generated by the propulsor alone. This translates to an additional 50% control authority at 3 kn for current Navy 21″ unmanned undersea vehicles. DEWEY : 620.1 ISSN : 0098-2202 En ligne : http://fluidsengineering.asmedigitalcollection.asme.org/issue.aspx?journalid=122 [...] [article] A method to generate propulsor side forces [texte imprimé] / Huyer, Stephen A., Auteur ; Dropkin, Amanda, Auteur ; James Dick, Auteur . - 2010 . - 09 p. fluids engineering Langues : Anglais (eng) in Transactions of the ASME . Journal of fluids engineering > Vol. 132 N° 2 (Fevrier 2010) . - 09 p. Mots-clés : generate  vehicle;  preswirl  propulsor;  upstream  stator;  downstream  rotor Résumé : A computational study was performed to investigate a method to generate vehicle maneuvering forces from a propulsor alone. A ducted, preswirl propulsor was configured with an upstream stator row and downstream rotor. During normal operation, the upstream stator blades are all situated at the same pitch angle and preswirl the flow into the propulsor while generating a roll moment to counter the moment produced by the rotor. By varying the pitch angles of the stator blade about the circumference, it is possible to both generate a mean stator side force and subsequently vary the axial velocity and swirl that is ingested into the propulsor. The rotor then generates a side force in response to the inflow. Both potential flow and fully viscous 3D Reynolds averaged Navier–Stokes (RANS) computations were used to predict the stator forces, velocity field, and rotor response. Potential flow methods were used for initial examination of a wide variety of stator configurations. The most promising were then modeled using RANS. The RANS inflow was then computed and used as velocity boundary conditions during rotor blade design using potential flow methods. Blade parameters including blade number, rake, skew, and a combination of the two were varied to characterize their effects. RANS was used to then validate the final propulsor design. Computations demonstrated that total side force coefficients on the order of 0.1 and moment coefficients about the stator leading edge of 0.066 could be generated by the propulsor alone. This translates to an additional 50% control authority at 3 kn for current Navy 21″ unmanned undersea vehicles. DEWEY : 620.1 ISSN : 0098-2202 En ligne : http://fluidsengineering.asmedigitalcollection.asme.org/issue.aspx?journalid=122 [...]