7 documents found, page 1 of 1
Lattice Boltzmann Modeling of Non-Newtonian Fluid Flows Under Non-Linear Slip V...
Reis, Francisco; Silva, Goncalo; Semiao, ViriatoFluid flows in microfluidic devices are often characterized by non-Newtonian rheology with non-linear wall slip behavior also observed. This work solves this problem class with the lattice Boltzmann method (LBM), proposing new advanced boundary scheme formulations to model the joint contribution of non-linear rheology and non-linear wall slip laws in application to microchannels of planar and circular cross-sec...
Performance Analysis of Multi Capillary Knudsen Heat Pumps
Ajuda, Ana; Silva, Goncalo; Semiao, ViriatoThe present work investigates the theoretical performance of the Knudsen heat pump (KHP), a novel heat pump concept in which the conventional mechanical compressor is replaced by a Knudsen compressor. This modification has the potential to reduce both maintenance requirements and energy consumption. The flow behavior within the Knudsen compressor, the core element of the KHP, is described using a simplified gas...
Syringe irrigation in confluent canals: A sequential computational fluid dynami...
Rito Pereira, Mário; Silva, Goncalo; Semiao, Viriato; Martins, Jorge; Silverio, Vania; Pascoal-Faria, Paula; Duarte, Isabel; Alves, NunoThis study aims to assess the influence of root canal preparation, irrigation needle design and its placement depth in the irrigation flow of confluent canals during syringe irrigation. A mandibular molar presenting two confluent canals in its mesial root was sequentially prepared and scanned by micro-computed tomography after mechanical preparation up to ProTaper Next system sizes X2 (25/.06v), X3 (30/.07v) an...
Lattice Boltzmann Modeling of Rotating Channel Flows
Silva, Goncalo; Semiao, ViriatoThe lattice Boltzmann method (LBM) is recognised as a well-established numerical technique, capable of solving a wide variety of fluid flow problems [1]. This study will focus on a very specific application: the LBM modeling of rotating channel flows [2]. Despite the apparent simplicity of this problem, current CFD commercial codes still show difficulties in solving it [3], and LBM is no exception [2]. This stu...
Syringe irrigation in confluent canals: A sequential computational fluid dynami...
Rito Pereira, Mário; Silva, Goncalo; Semiao, Viriato; Martins, Jorge N. R.; Silverio, Vania; Pascoal-Faria, Paula; Duarte, Isabel; Alves, NunoThis study aims to assess the influence of root canal preparation, irrigation needle design and its placement depth in the irrigation flow of confluent canals during syringe irrigation. A mandibular molar presenting two confluent canals in its mesial root was sequentially prepared and scanned by micro-computed tomography after mechanical preparation up to ProTaper Next system sizes X2 (25/.06v), X3 (30/.07v) an...
Experimental validation of a computational fluid dynamics model using micro‐par...
Pereira, Mário; Silva, Gonçalo; Semiao, Viriato; Silverio, Vania; Martins, Jorge; Pascoal-Faria, Paula; Alves, Nuno; Dias, Juliana; Ginjeira, AntónioThis study aimed to experimentally validate a computational fluid dynamics (CFD) model, using micro-particle image velocimetry (micro-PIV) measurements of the irrigation flow velocity field developed in confluent canals during irrigation with a side-vented needle. A microchip with confluent canals, manufactured in polydimethylsiloxane was used in a micro-PIV analysis of the irrigation flow using a side-vented n...
Contrasts in the basins of attraction of structurally identical iterative root ...
Basto, Mário; Basto, Luís P.; Semiao, Viriato; Calheiros, Francisco L.A numerical comparison is performed between three methods of third order with the same structure, namely BSC, Halley’s and Euler–Chebyshev’s methods. As the behavior of an iterative method applied to a nonlinear equation can be highly sensitive to the starting points, the numerical comparison is carried out, allowing for complex starting points and for complex roots, on the basins of attraction in the complex p...