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Relationship between accuracy and number of velocity particles of the finite-difference lattice Boltzmann method in velocity slip simulations / Minoru Watari 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) . - 11 p. Titre : Relationship between accuracy and number of velocity particles of the finite-difference lattice Boltzmann method in velocity slip simulations Type de document : texte imprimé Auteurs : Minoru Watari, Auteur Année de publication : 2011 Article en page(s) : 11 p. Note générale : fluids engineering Langues : Anglais (eng) Mots-clés : momentum;  flow  (dynamics);  particulate  matter;  computer  simulation;  simulation;  relaxation  (physics);  equilibrium  (physics);  engineering  simulation;  equations;  simulation  results Résumé : Relationship between accuracy and number of velocity particles in velocity slip phenomena was investigated by numerical simulations and theoretical considerations. Two types of 2D models were used: the octagon family and the D2Q9 model. Models have to possess the following four prerequisites to accurately simulate the velocity slip phenomena: (a) equivalency to the Navier–Stokes equations in the N-S flow area, (b) conservation of momentum flow Pxy in the whole area, (c) appropriate relaxation process in the Knudsen layer, and (d) capability to properly express the mass and momentum flows on the wall. Both the octagon family and the D2Q9 model satisfy conditions (a) and (b). However, models with fewer velocity particles do not sufficiently satisfy conditions (c) and (d). The D2Q9 model fails to represent a relaxation process in the Knudsen layer and shows a considerable fluctuation in the velocity slip due to the model’s angle to the wall. To perform an accurate velocity slip simulation, models with sufficient velocity particles, such as the triple octagon model with moving particles of 24 directions, are desirable. DEWEY : 620.1 ISSN : 0098-2202 En ligne : http://fluidsengineering.asmedigitalcollection.asme.org/Issue.aspx?issueID=27433 [...] [article] Relationship between accuracy and number of velocity particles of the finite-difference lattice Boltzmann method in velocity slip simulations [texte imprimé] / Minoru Watari, Auteur . - 2011 . - 11 p. fluids engineering Langues : Anglais (eng) in Transactions of the ASME . Journal of fluids engineering > Vol. 132 N° 10 (Octobre 2010) . - 11 p. Mots-clés : momentum;  flow  (dynamics);  particulate  matter;  computer  simulation;  simulation;  relaxation  (physics);  equilibrium  (physics);  engineering  simulation;  equations;  simulation  results Résumé : Relationship between accuracy and number of velocity particles in velocity slip phenomena was investigated by numerical simulations and theoretical considerations. Two types of 2D models were used: the octagon family and the D2Q9 model. Models have to possess the following four prerequisites to accurately simulate the velocity slip phenomena: (a) equivalency to the Navier–Stokes equations in the N-S flow area, (b) conservation of momentum flow Pxy in the whole area, (c) appropriate relaxation process in the Knudsen layer, and (d) capability to properly express the mass and momentum flows on the wall. Both the octagon family and the D2Q9 model satisfy conditions (a) and (b). However, models with fewer velocity particles do not sufficiently satisfy conditions (c) and (d). The D2Q9 model fails to represent a relaxation process in the Knudsen layer and shows a considerable fluctuation in the velocity slip due to the model’s angle to the wall. To perform an accurate velocity slip simulation, models with sufficient velocity particles, such as the triple octagon model with moving particles of 24 directions, are desirable. DEWEY : 620.1 ISSN : 0098-2202 En ligne : http://fluidsengineering.asmedigitalcollection.asme.org/Issue.aspx?issueID=27433 [...]