Documents disponibles écrits par cet auteur

Computational towing tank procedures for single run curves of resistance and propulsion / Tao Xing in Transactions of the ASME . Journal of fluids engineering, Vol. 130 N° 10 (Octobre 2008) 

Public ISBD [article]  in Transactions of the ASME . Journal of fluids engineering > Vol. 130 N° 10 (Octobre 2008) . - 14 p. Titre : Computational towing tank procedures for single run curves of resistance and propulsion Type de document : texte imprimé Auteurs : Tao Xing, Auteur ; Pablo Carrica, Auteur ; Frederick Stern, Auteur Année de publication : 2009 Article en page(s) : 14 p. Note générale : Fluids engineering Langues : Anglais (eng) Mots-clés : Computational  towing  tank;  run  curve Résumé : A procedure is proposed to perform ship hydrodynamics computations for a wide range of velocities in a single run, herein called the computational towing tank. The method is based on solving the fluid flow equations using an inertial earth-fixed reference frame, and ramping up the ship speed slowly such that the time derivatives become negligible and the local solution corresponds to a quasi steady-state. The procedure is used for the computation of resistance and propulsion curves, in both cases allowing for dynamic calculation of the sinkage and trim. Computational tests are performed for the Athena R/V model DTMB 5365, in both bare hull with skeg and fully appended configurations, including two speed ramps and extensive comparison with experimental data. Comparison is also performed against steady-state points, demonstrating that the quasisteady solutions obtained match well the single-velocity computations. A verification study using seven systematically refined grids was performed for one Froude number, and grid convergence for resistance coefficient, sinkage, and trim were analyzed. The verification study concluded that finer grids are needed to reach the asymptotic range, though validation was achieved for resistance coefficient and sinkage but not for trim. Overall results prove that for medium and high Froude numbers the computational towing tank is an efficient and accurate tool to predict curves of resistance and propulsion for ship flows using a single run. The procedure is not possible or highly difficult using a physical towing tank suggesting a potential of using the computational towing tank to aid the design process. En ligne : http://fluidsengineering.asmedigitalcollection.asme.org/Issue.aspx?issueID=27341 [...] [article] Computational towing tank procedures for single run curves of resistance and propulsion [texte imprimé] / Tao Xing, Auteur ; Pablo Carrica, Auteur ; Frederick Stern, Auteur . - 2009 . - 14 p. Fluids engineering Langues : Anglais (eng) in Transactions of the ASME . Journal of fluids engineering > Vol. 130 N° 10 (Octobre 2008) . - 14 p. Mots-clés : Computational  towing  tank;  run  curve Résumé : A procedure is proposed to perform ship hydrodynamics computations for a wide range of velocities in a single run, herein called the computational towing tank. The method is based on solving the fluid flow equations using an inertial earth-fixed reference frame, and ramping up the ship speed slowly such that the time derivatives become negligible and the local solution corresponds to a quasi steady-state. The procedure is used for the computation of resistance and propulsion curves, in both cases allowing for dynamic calculation of the sinkage and trim. Computational tests are performed for the Athena R/V model DTMB 5365, in both bare hull with skeg and fully appended configurations, including two speed ramps and extensive comparison with experimental data. Comparison is also performed against steady-state points, demonstrating that the quasisteady solutions obtained match well the single-velocity computations. A verification study using seven systematically refined grids was performed for one Froude number, and grid convergence for resistance coefficient, sinkage, and trim were analyzed. The verification study concluded that finer grids are needed to reach the asymptotic range, though validation was achieved for resistance coefficient and sinkage but not for trim. Overall results prove that for medium and high Froude numbers the computational towing tank is an efficient and accurate tool to predict curves of resistance and propulsion for ship flows using a single run. The procedure is not possible or highly difficult using a physical towing tank suggesting a potential of using the computational towing tank to aid the design process. En ligne : http://fluidsengineering.asmedigitalcollection.asme.org/Issue.aspx?issueID=27341 [...]

Integral force/moment waterjet model for CFD simulations / Manivannan Kandasamy in Transactions of the ASME . Journal of fluids engineering, Vol. 132 N° 10 (Octobre 2010) 

Public ISBD [article]  in Transactions of the ASME . Journal of fluids engineering > Vol. 132 N° 10 (Octobre 2010) . - 09 p. Titre : Integral force/moment waterjet model for CFD simulations Type de document : texte imprimé Auteurs : Manivannan Kandasamy, Auteur ; Seng Keat Ooi, Auteur ; Pablo Carrica, Auteur Année de publication : 2011 Article en page(s) : 09 p. Note générale : fluids engineering Langues : Anglais (eng) Mots-clés : force;  flow  (dynamics);  computational  fluid  dynamics;  engineering  simulation;  ships;  hull Index. décimale : 620.1 Essais des matériaux. Défauts des matériaux. Protection des matériaux Résumé : An integral force/moment waterjet model for computational fluid dynamics (CFD) is derived for ship local flow/powering predictions, including sinkage and trim. The waterjet induced reaction forces and moment and waterjet/hull interaction stern force replicate the effects of the waterjet without requiring detailed simulations of the waterjet system. The model extends the International Towing Tank Conference (ITTC) waterjet model for sinkage and trim by using an alternative control volume also appropriate for CFD and by including vertical forces and pitching moment in the waterjet/hull force/moment balance. The same grid is used for both without and with waterjet simulations. The CFD waterjet model requires limited waterjet geometry (inlet and outlet areas and locations, and weight of working fluid) and several waterjet flow (mass flow rate, inlet pressure force, inlet and outlet momentum correction factors and flow angles, and stern force and location) input variables. The CFD waterjet model can be used for local flow predictions by using waterjet flow input variables provided by ITTC waterjet model test data, including additional data for waterjet induced inlet pressure and stern forces. It can also be used for powering predictions once waterjet flow input variable correlations are available based on CFD for the waterjet system and/or experimental data. The CFD waterjet model is demonstrated for local flow predictions for the DTMB 5594 high-speed sealift ship model for which ITTC waterjet model test data, including additional data for waterjet induced stern forces, are available. Correlations for the waterjet flow input variables are shown to be feasible using a combination of CFD and experimental data for the waterjet system for three different hulls. DEWEY : 620.1 ISSN : 0098-2202 En ligne : http://fluidsengineering.asmedigitalcollection.asme.org/Issue.aspx?issueID=27433 [...] [article] Integral force/moment waterjet model for CFD simulations [texte imprimé] / Manivannan Kandasamy, Auteur ; Seng Keat Ooi, Auteur ; Pablo Carrica, Auteur . - 2011 . - 09 p. fluids engineering Langues : Anglais (eng) in Transactions of the ASME . Journal of fluids engineering > Vol. 132 N° 10 (Octobre 2010) . - 09 p. Mots-clés : force;  flow  (dynamics);  computational  fluid  dynamics;  engineering  simulation;  ships;  hull Index. décimale : 620.1 Essais des matériaux. Défauts des matériaux. Protection des matériaux Résumé : An integral force/moment waterjet model for computational fluid dynamics (CFD) is derived for ship local flow/powering predictions, including sinkage and trim. The waterjet induced reaction forces and moment and waterjet/hull interaction stern force replicate the effects of the waterjet without requiring detailed simulations of the waterjet system. The model extends the International Towing Tank Conference (ITTC) waterjet model for sinkage and trim by using an alternative control volume also appropriate for CFD and by including vertical forces and pitching moment in the waterjet/hull force/moment balance. The same grid is used for both without and with waterjet simulations. The CFD waterjet model requires limited waterjet geometry (inlet and outlet areas and locations, and weight of working fluid) and several waterjet flow (mass flow rate, inlet pressure force, inlet and outlet momentum correction factors and flow angles, and stern force and location) input variables. The CFD waterjet model can be used for local flow predictions by using waterjet flow input variables provided by ITTC waterjet model test data, including additional data for waterjet induced inlet pressure and stern forces. It can also be used for powering predictions once waterjet flow input variable correlations are available based on CFD for the waterjet system and/or experimental data. The CFD waterjet model is demonstrated for local flow predictions for the DTMB 5594 high-speed sealift ship model for which ITTC waterjet model test data, including additional data for waterjet induced stern forces, are available. Correlations for the waterjet flow input variables are shown to be feasible using a combination of CFD and experimental data for the waterjet system for three different hulls. DEWEY : 620.1 ISSN : 0098-2202 En ligne : http://fluidsengineering.asmedigitalcollection.asme.org/Issue.aspx?issueID=27433 [...]