Accelerating the Lagrangian Method for Modeling Transient Particle Transport in Indoor Environments

Figures & data

FIG. 1. Configuration of the chamber studied by Zhang et al. (2009).

TABLE 1 Cases designed to verify the method of estimating the necessary particle number

Case no.	Target zone	Volume of target zone (m^3)	Characteristics of source duration	Duration of particle source(s)	Calculated necessary particle number (millions)
1	Breathing zone	0.027	Δt	0.05	2.24
2	Whole room	20.2	Δt	0.05	0.003
3	Breathing zone	0.027	τ	273	3.55

FIG. 2. Particle number independence tests for (a) Case 1, (b) Case 2, and (c) Case 3.

FIG. 3. Comparison of normalized particle concentrations predicted by the combined Lagrangian and superimposition method and the pure Lagrangian method.

FIG. 4. Factor of reduction in particle number as a function of particle source duration when the superimposition method is used.

FIG. 5. Comparison of normalized particle concentrations predicted by the combined Lagrangian and time-averaging method and the pure Lagrangian method for (a) Case 1 and (b) Case 3.

FIG. 6. Comparison of normalized particle concentrations predicted by the combined Lagrangian, superimposition, and time-averaging method and the pure Lagrangian method.

TABLE 2 Comparison of computing cost

	Computing time (h)^a
Case no.	Pure Lagrangian	Lagrangian + superimposition	Lagrangian + time-averaging	Lagrangian + superimposition + time-averaging
1	48.9	N/A	1.6	N/A
3	64.8	48.9	2.2	1.6

^aThe computing time was estimated on a single core computer, with two 3.2 GHz Intel(R) Xeon(R) processors and 12 GB of memory.

FIG. 7. Comparison of the numerical results for transient particle concentration with the corresponding experimental data: (a) Point 1 and (b) Point 2.

FIG. 8. Comparison of normalized particle concentrations predicted by the Lagrangian method with particle numbers that were estimated using α values of 1%, 10%, and 100%.

Zhang, N., Zheng, Z., Eckels, S., Nadella, V. B., and Sun, X. (2009). Transient Response of Particle Distribution in a Chamber to Transient Particle Injection. Part. Part. Syst. Charact., 26:199–209.

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