Triangular grid

M.J. Frits, Two-Dimensional Lagrangian Fluid Dynamics Using Triangular Grids, in Finite-Difference Techniques for Vectorized Fluid Dynamics Calculations (edited by D.L. Book), Springer-Verlag, New York, 1981. 

Figure 2.7 Example of a structured grid (left) and of an unstructured grid constructed from triangular elements (right).

Hole Layout. To increase the uniformity of fluidization, it is common to lay out the holes in triangular or square pitch as shown in Fig. 4. All the holes in a grid with triangular pitch are equidistant. This is not the case for a grid with square pitch. Triangular pitch will also result in more holes per unit area. 

The relationship between the grid hole pitch, Lh, and the number hole density (holes per unit area of the bed), Nd, depends on whether the holes are laid out in triangular or square pitch. 

Figure 4. The relationship between hole density and grid hole pitch for triangular and square pitch.

Example 4 Design a flat, perforated-plate grid for the polyethylene reactor schematically shown in Fig. 11, and calculate the gas j et penetration depth. Use a triangular pitch. System parameters are ... 

Three-dimensional detector coverage, as shown in Figure 8-5, can be obtained by a triangular grid (isometric) pattern of point or open path detectors, with a maximum separation less than the gas cloud diameter that can... 

Fig. 14. A grid superimposed on the basal plane of a triangular single-layer M0S2 nanocluster. The intersections of the white lines indicate the sulfur atomic positions on the basal plane. At the edges, the protrusions are observed to be shifted out of registry with the basal plane lattice. An STM line scan across the bright brim of the single-layer M0S2 nanocluster is illustrated on the right. The arrow indicates the direction and position of the scan in the image.

In systems involving three components, composition is plotted on a triangular section (Figure 6.2). Pure components are represented at the comers and the grid lines show the amount of each component. All of the lines parallel to AB are lines on which the %C is constant. Those nearest C have the greatest amount of C. To represent temperature, a third dimension is needed. Figure 6.3 is a sketch of a three-dimensional ternary diagram in which temperature is the vertical coordinate. 

A triangular grid for representing the compositions in a three-component system. 

Three 3-4 feet (ft) long poles (for hexagonal or triangular grids only)... 

All the solutions which are necessary to form an equilateral triangular llxllxll, 61-element ternary phase diagram were prepared automatically by a liquid dispensing machine. Mixtures with compositions of each component ranged from 0 to 100% in 10% increments. On the 3 in quartz wafer used, 144 wells form a 12 x 12 square grid for the catalyst spots. Each of these elements has a diameter of 3 mm. The whole array is calcined at 500 °C for 12 h and subsequently for an additional 12 h at 800 °C under a 6% H2 in argon atmosphere [80],... 

Figure 9. The triangular grid early in a calculation of wave flow over a halfcylinder. The first wave of a wave train has passed over the cylinder from the left.

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