Validation of Flux Correction on Three-Dimensional Strand Grids with an Overset Cartesian Grid

2017 ◽  
Author(s):  
Dalon Work ◽  
Yushi Yanagita ◽  
Ted Giblette ◽  
Aaron J. Katz ◽  
Douglas F. Hunsaker
Keyword(s):  
Three Dimensional ◽  
Cartesian Grid ◽  
Flux Correction ◽  
Strand Grids

Segregation Patterns and the Phase-Field 3D-Model for Adiabatic Phase Transition in Al-Cu Alloys

2013 ◽  
Vol 668 ◽  
pp. 870-874
Author(s):  
Heng Min Ding ◽  
Tie Qiao Zhang ◽  
Lv Chun Pu
Keyword(s):  
Dendritic Growth ◽  
3D Model ◽  
Three Dimensional ◽  
Cartesian Grid ◽  
Solute Diffusion ◽  
Solute Redistribution ◽  
Cu Alloys ◽  
Solid Phases ◽  
Solid Liquid ◽  
Liquid And Solid Phases

In the paper, a model basing on solute conservative in every unit is developed for solving the solute diffusion equation during solidification. The model includes time-dependent calculations for temperature distribution, solute redistribution in the liquid and solid phases. Three-dimensional computations are performed for Al-Cu dendritic growth into an adiabatic and highly supersaturated liquid phase. A numerical algorithm was developed to explicitly track the sharp solid/liquid (S/L) interface on a fixed Cartesian grid. Three-dimensional mesoscopic calculations were performed to simulate the evolution of equiaxed dendritic morphologies.

Application of a Cartesian-Grid Immersed Boundary Method to 3D In-Cylinder Flow

2012 ◽  
Author(s):  
Claudia Günther ◽  
Matthias Meinke ◽  
Wolfgang Schröder
Keyword(s):  
Level Set ◽  
Immersed Boundary Method ◽  
Three Dimensional ◽  
Cartesian Grid ◽  
Distance Functions ◽  
Immersed Boundary ◽  
Splitting Algorithm ◽  
Signed Distance ◽  
Boundary Method ◽  
Cylinder Flow

In this work, a Cartesian-grid immersed boundary method using a cut-cell approach is applied to three-dimensional in-cylinder flow. A hierarchically coupled level-set solver is used to capture the boundary motion by a signed distance function. Topological changes in the geometry due to the opening and closing events of the valves are modeled consistently using multiple signed distance functions for the different components of the engine and taking advantage of a level-set reinitialization method. A continuous discretization of the flow equations in time near the moving interfaces is used to prevent nonphysical oscillations. To ensure an efficient implementation, independent grid adaptation for the flow and the level-set grid is applied. A narrow band approach and an efficient joining/splitting algorithm for the level-set functions minimize the computational overhead to track multiple interfaces. The ability of the current method to handle complex 3D setups is demonstrated for the interface capturing and the flow solution in a three-dimensional piston engine geometry.

Development of a Household Vacuum Cleaner With a New Cyclone Dust Collector

2007 ◽  
Author(s):  
Shoji Hayashi ◽  
Masatoshi Watanabe ◽  
Yukiji Iwase ◽  
Kyoichi Kanno ◽  
Keiichi Fujimori
Keyword(s):  
High Performance ◽  
Three Dimensional ◽  
Cartesian Grid ◽  
Dust Collector ◽  
Grid System ◽  
Vacuum Cleaner ◽  
Pressure Losses ◽  
Stepped Surfaces ◽  
Cyclone Dust Collector ◽  
High Performance Computers

A household vacuum cleaner named “Tatsumaki cyclone” with a new cyclone dust collector was developed. It has a unique horizontal layout called the inverted cyclone layout that features a dust bunker adjacent to a cyclone cylinder with an up-draught airflow. It also has a new airflow arrangement called triple-suction airflow that separates airflow after removing dust at the cyclone cylinder. The main suction airflow is exhausted from the main port (which is downstream of the cyclone cylinder) through an inner cylinder. The sub-suction airflow is exhausted from the dust bunker after it heavily compresses the dust (sub port). The center suction airflow is exhausted from the center port. In this study, we used the Cartesian grid system to simulate the flow field inside the dust collector. This system uses only rectangular parallelepiped meshes; profiles of the dust collector were represented by stepped surfaces of cubic meshes. Each mesh was generated based on whether it was inside or outside the solid body of the dust collector. High-performance computers have recently been used to help generate super-fine meshes that fit closely the smooth shape of a dust collector. The Cartesian grid system has the advantage of being able to quickly generate square-meshes of complex shape that can be converted directly from the CAD data. We simulated the velocity distribution of single-suction, twin-suction and triple-suction models. The single-suction model had only a main port to exhaust airflow, the twin-suction model had a main port, and a sub port, and the triple-suction model had a main port, a sub port, and a center port. In this study, a Cartesian grid system with a finite difference method was used to correct the unsteady three-dimensional flows. After the simulation, we experimented with pressure losses and measured change in air quantity by the dust load of each model. These steps enabled us to develop a new cyclone dust collector called Tatsumaki cyclone as part of a compact household vacuum cleaner with lower pressure loss and a larger capacity dust bunker.

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