Hour‐to‐Hour Height Variation
Rerun the single particle concentration simulation
![](../images/cbase009.png)
But turn on the center‐of‐Mass trajectory output
![](../images/cmtraj001.png)
![](../images/xamp07m.png)
Sensitivity of Maximum Concentration to Grid Size
Edit conc_part.bat (or .sh)
with different concentration grid resolutions: 0.10, 0.20, ...
![](../images/xamp07a.png)
Simulation with 100 particles
![](../images/xamp07b.png)
Simulation with 1000 particles
![](../images/xamp07c.png)
Simulation with 10000 particles
![](../images/xamp07d.png)
Maximum concentration differences with 0.10 grid -
- 100 to 1000 particles: 50%
- 1000 to 10000 particles: 36%
Maximum concentration differences with 0.20 grid -
- 100 to 1000 particles: 50%
- 1000 to 10000 particles: 15%
Sensitivity of Minimum Concentration to Particle Number
Edit conc_part.bat (or .sh)
for grid size 0.20 use gridplot and display plot.ps
![](../images/xamp07e.png)
Simulation with 100 particles ... min = 5.3E-15
![](../images/xamp07f.png)
Simulation with 1000 particles ... min = 5.3E-16
![](../images/xamp07g.png)
Simulation with 10000 particles ... min = 5.3E-17
![](../images/xamp07h.png)
Hypothetical example
![](../images/xamp07x.png)
![](../images/xamp07y.png)
- A finer concentration grid requires more particles
- Or fewer particles could utilize a coarser grid
- Particle number versus grid size sensitivity can be evaluated using the maximum concentration
- Minimum concentrations are also affected because the lower limit is the mass of one particle divided by the grid cell size
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