We produced data with these varying grid sizes by dividing the same original map of Allegheny county into smaller cells to obtain "larger" grids (in terms of cell counts).
Then, 3D computational fluid dynamics (CFD) simulations with an optimized grid size determined by a grid convergence study were performed with the 107-species reduced mechanism and the 5-component certification gasoline surrogate.
Among them are grid size (usually 15 by 15 for a daily paper, 21 by 21 for a Sunday puzzle), minimum word length (three letters) and a ban on "unchecked letters" ("Every square has to be part of two answers, across and down," Mr. Shortz said).
If the grid size (interval) used by optimal numerical search is Δ, the total number of grid points is x k max / Δ for each relay.
Following the aforementioned procedures, a grid layer inside the study area is created with user-specified grid size (1000 feet by 1000 feet in the case study).
The grid size is given by Δt for the time discretization, and Δx for the space discretization, and varies from row to row.
Although a finer grid could give a more accurate solution, the overall pattern of the solutions is insensitive to the chosen grid size, as confirmed by simulations using a finer grid with a half grid size.
A very high-resolution metropolitan digital elevation model with 1 m grid size is constructed by combining these two data sources, which are then joined with high-resolution bathymetry data to produce a seamless bathymetry and land topography input for detailed tsunami numerical model runs.
