Application Note: Why Just Double Your Pleasure?
The most significant new feature in the new release is the multi-block meshing model. The model allows users to create multiple grids to efficiently discretize complex flow domains and increase the speed and accuracy of simulations.
Each mesh block spans a certain region of the flow domain and contains the standard finite difference grid. Blocks can be nested within other clocks or linked with other blocks at their boundaries.
The multi-block model also offers more flexibility in defining boundary conditions at domain boundaries. Each mesh block can have its own set of standard FLOW-3D boundary conditions.
Using linked blocks, users can reduce problem size to create a numerical domain that is more suitable to the actual flow region. Nested blocks can be used to achieve concentrated local resolution in areas of interest. Multi-layered meshes can be created by embedding a nested block in a larger block, and so on.
In benchmark tests, problems set up using the multi-block model completed the simulation process as much as 95% faster. On average, the multi-block problems required 60% less time, memory, and disk space. Multi-block setup is easy due to the inherent simplicity of each block.
To model the high-pressure die casting above, designed by Amcan Castings (Hamilton, Ontario) four linked mesh blocks were used for the simulation on the left and one mesh block for the one on the right (mesh blocks outlines by rectangular blocks). The multi-block approach speeds up the calculation by 37.5% at the same time reducing the memory use by nearly 40% over the more conventional single block approach.