Experimental Determination of Supermicrometer Particle Fate Subsequent to a Point Release within a Room under Natural and Forced Mixing

Figures & data

FIG. 1 The floor plan of the experimental chamber. Grid rows are denoted by numbers and columns by letters, with length aspect 0.3 m. Aerosol was released in grid point 7C (star) at height 0.64 m. Forced mixing was induced by two 0.08 m diameter instrument fans on the floor at grid point 1D (boxes, arrows indicate direction of flow). The 0.3 m diameter exhaust fan was located in the wall, on the floor, at grid point 9F (box, arrow indicates direction of flow).

TABLE 1 In all experiments (Exp), the Vibrating Orifice Aerosol Generator (VOAG) was operated with a 20 μ m orifice, fluid flow rate of 0.44 mL/min, and the specified frequency (Freq). Temperature (Temp) and relative humidity (RH) were measured in the chamber core prior to the aerosol release

		Calculated		Initial
Exp	Freq (kHz)	dp (μ m)	da (μ m)	Temp (°C)	RH (%)
Natural mixing
T1	49.33	2.95	3.43	19.3	46.5
T2	49.06	2.95	3.43	20.6	42.4
T3	48.91	2.96	3.44	19.3	52.1
T4	48.47	2.97	3.44	19.6	46.3
T5	58.04	13.7	13.3	16.8	52.5
T6	56.67	13.9	13.4	18.8	50.1
T7	56.67	13.9	13.4	18.4	56.2
Forced mixing
T8	52.33	2.88	3.34
T9	50.24	2.93	3.41
T10	50.78	2.92	3.39
T11	50.74	2.92	3.39
T12	54.73	14.0	13.5
T13	53.84	14.1	13.6	18.1	59.0
T14	52.21	14.2	13.7	16.8	41.5

TABLE 2 Cumulative fluorescein mass, relative to the mean value in each trial, deposited on 0.02 m³ foil floor samplers centered in each grid point over 90 min (20 min aerosol release followed by 70 min of deposition) under natural and forced mixing. Aerosol was released 0.64 m above the floor at grid point 7C. Forced mixing was induced by two 0.08 m diameter instrument fans on the floor, blowing towards each other in grid point 1D

	Relative cumulative fluorescein mass
	Natural mixing							Forced mixing
	da ∼ 3 μ m				da ∼ 14 μ m			da ∼ 3 μ m				da ∼ 14 μ m
Grid point	T1	T2	T3	T4	T5	T6	T7	T8	T9	T10	T11	T12	T13	T14
1A	0.54	0.24	0.49	0.55	1.1	0.98	0.95	1.0	1.0	1.0	1.1	0.91	0.94	0.85
1B	0.60	0.34	0.59	0.74	1.6	1.4	1.5	1.0	1.0	1.0	0.96	0.95	0.96	0.88
1C	0.66	0.52	0.75	0.69	1.7	1.6	1.7	1.0	1.0	1.0	0.92	0.97	1.0	0.88
1D	Fan location
1E	0.71	0.69	0.57	0.59	1.2	1.4	1.7	0.97	1.0	1.1	1.1	1.1	1.2	1.1
1F	0.71	0.74	0.62	0.68	0.83	0.86	0.99	1.0	0.91	1.1	1.1	1.1	1.1	1.1
1G	0.58	1.8	0.79	0.69	0.38	0.32	0.24	1.0	0.96	1.0	1.1	1.1	1.2	1.1
2A	0.61	0.51	0.65	0.69	1.3	1.6	1.2	1.0	1.0	1.1	0.96	0.93	1.0	0.85
2B	0.57	0.55	0.75	0.44	1.8	1.9	1.6	1.1	1.1	1.0	0.94	0.94	0.99	0.87
2C	0.73	0.54	0.78	0.76	1.9	1.9	2.0	1.0	1.0	1.0	0.95	0.90	0.94	0.82
2D	0.81	0.57	0.88	0.72	1.7	1.8	1.9	1.2	1.1	1.0	1.4	2.2	2.0	2.0
2E	0.91	0.72	0.99	0.67	1.3	1.5	1.6	1.0	1.0	1.0	0.94	1.1	1.0	1.1
2F	0.90	0.64	0.95	0.65	1.2	0.99	1.2	1.0	0.99	1.1	1.1	1.1	1.1	1.1
2G	0.66	1.4	0.81	0.63	0.84	0.40	0.36	1.0	1.0	1.0	1.1	1.2	1.2	1.1
3A	0.75	0.54	0.62	0.54	1.2	1.8	1.3	1.0	0.99	1.0	0.91	0.91	0.93	0.84
3B	0.66	0.62	0.77	0.79	1.8	2.1	2.0	1.0	1.0	1.0	0.93	0.94	0.93	0.83
3C	0.73	0.57	089	0.77	2.0	2.0	2.2	1.0	1.0	0.98	0.96	0.90	0.91	0.84
3D	0.81	0.59	0.93	0.71	1.7	1.8	1.9	1.0	0.93	0.98	1.1	1.0	1.0	0.99
3E	0.93	1.2	0.94	0.67	1.3	1.4	1.3	1.0	1.0	1.0	0.94	1.0	0.98	1.1
3F	0.95	0.67	0.78	0.62	1.1	1.0	1.2	1.1	1.0	1.0	0.97	1.1	1.1	1.1
3G	0.76	1.5	0.77	0.55	0.88	0.36	0.68	1.0	1.0	1.0	1.1	1.1	1.1	1.1
4A	0.76	0.60	0.87	0.46	1.3	1.9	1.4	0.99	1.0	1.0	0.93	0.93	0.95	0.84
4B	0.75	1.3	0.85	0.75	1.9	2.0	2.0	1.0	0.96	0.98	1.1	0.92	0.90	0.82
4C	0.85	2.4	0.86	0.71	2.0	2.0	2.1	0.97	0.95	0.95	1.1	0.84	0.88	0.89
4D	0.82	0.62	0.89	0.83	1.8	1.8	1.7	1.0	0.94	0.96	0.94	—	0.89	0.92
4E	0.88	0.62	0.82	0.80	1.3	1.2	1.1	0.95	1.0	1.0	0.94	1.1	0.97	1.1
4F	0.96	0.66	0.82	0.79	1.0	0.89	1.1	1.0	1.0	1.0	0.95	—	1.0	1.1
4G	0.93	3.0	0.51	0.75	0.80	0.31	0.96	1.1	0.99	1.1	1.1	1.1	1.1	1.0
5A	0.75	0.39	1.5	0.61	1.2	1.2	1.3	1.1	1.0	1.0	0.95	0.91	0.90	0.83
5B	0.75	0.66	0.84	0.80	1.7	1.6	1.8	1.0	0.95	0.95	0.94	0.90	0.92	0.86
5C	0.76	2.0	0.80	0.78	1.8	1.9	1.7	0.97	0.98	0.93	0.93	0.94	0.94	0.87
5D	0.90	2.9	0.92	1.0	1.6	1.6	1.3	1.0	0.95	0.95	0.94	1.0	0.95	0.95
5E	0.99	2.2	0.92	1.1	1.2	0.99	0.79	0.98	0.95	0.98	1.1	1.1	0.97	1.1
5F	0.99	0.62	0.93	1.1	0.89	0.83	0.95	1.0	0.99	1.0	1.1	1.1	1.0	1.2
5G	1.1	1.4	0.87	1.1	0.73	0.28	0.90	0.96	1.1	1.0	1.1	1.1	1.1	1.0
6A	0.84	0.39	0.81	0.98	1.1	0.98	1.3	0.93	0.97	0.89	0.90	0.85	0.90	0.84
6B	0.76	067	0.81	0.89	1.4	0.99	1.3	0.94	0.94	0.91	0.92	0.92	0.89	0.86
6C	0.98	0.55	0.94	0.88	1.6	1.6	1.2	0.92	0.92	0.88	1.1	0.97	0.94	0.90
6D	1.2	1.7	1.0	0.93	1.1	1.2	0.78	0.96	0.95	0.90	0.93	1.0	0.97	0.96
6E	1.3	0.65	1.2	1.2	0.90	0.82	0.57	0.96	0.99	1.0	0.92	1.1	0.94	1.1
6F	1.5	0.81	1.1	1.3	0.72	0.72	0.74	0.96	1.1	1.0	1.1	1.0	1.0	1.2
6G	1.4	3.7	0.99	1.3	0.64	0.42	0.91	1.0	1.0	1.0	1.0	1.0	1.2	0.97
7A	0.75	0.57	0.70	1.2	1.1	0.47	0.81	0.92	0.83	0.91	0.95	0.78	0.80	0.78
7B	0.92	0.59	0.79	1.2	1.0	0.51	0.41	1.1	0.86	0.87	0.88	0.87	0.86	0.85
7C	Release location
7D	1.1	0.54	1.3	1.2	0.21	0.73	0.36	0.96	0.98	1.0	0.96	0.98	0.91	1.0
7E	1.3	0.52	1.2	1.3	0.49	0.61	0.42	0.99	1.1	1.0	0.95	1.0	0.99	1.2
7F	1.4	0.58	1.4	1.3	0.52	0.64	0.58	1.0	1.0	1.0	0.91	1.1	1.1	1.2
7G	1.5	3.1	1.3	1.4	0.52	0.51	0.82	0.98	1.0	1.1	1.1	1.0	1.1	1.0
8A	1.0	0.75	1.1	1.5	0.74	0.27	0.39	0.95	0.92	1.1	0.94	0.75	0.77	0.76
8B	1.3	1.6	1.5	1.4	0.53	0.34	0.24	0.97	0.96	0.83	0.98	0.84	0.78	0.82
8C	1.4	0.50	1.5	1.3	0.14	0.38	0.17	0.92	1.0	0.90	1.0	0.91	0.87	0.98
8D	1.4	0.56	1.4	1.4	0.05	0.43	0.18	0.97	1.0	0.94	1.0	1.0	0.91	1.2
8E	1.4	0.56	1.3	1.4	0.09	0.48	0.27	1.0	1.0	1.0	1.0	1.1	0.91	1.2
8F	1.6	1.2	1.4	1.4	0.32	0.50	0.48	1.0	1.0	1.0	0.92	1.1	1.0	1.2
8G	1.2	1.9	1.4	1.5	0.33	0.54	0.70	1.1	1.0	1.1	1.1	0.96	1.2	0.97
9A	1.4	0.54	1.5	1.7	0.59	0.20	0.25	1.0	0.98	1.0	1.0	0.72	0.71	0.72
9B	1.4	0.73	1.5	1.4	0.26	0.23	0.13	0.99	0.99	1.0	0.92	0.83	0.84	0.85
9C	1.4	0.77	1.4	1.4	0.11	0.29	0.16	1.0	1.0	0.97	0.89	0.90	0.92	1.0
9D	1.5	0.61	1.3	1.4	0.06	0.32	0.17	0.96	1.0	1.0	1.1	0.94	0.97	1.1
9E	1.5	0.85	1.4	1.4	0.06	0.38	0.25	1.0	1.0	1.0	0.93	0.99	0.99	1.1
9F	1.6	0.93	1.5	1.4	0.11	0.41	0.40	0.98	1.1	1.1	0.96	1.0	1.1	1.1
9G	1.5	0.84	1.5	1.5	0.23	0.42	0.44	1.0	1.1	1.0	1.0	0.92	1.2	0.90
CV (%)	31	76	30	35	59	61	60	4	5	5	9	19	18	19

FIG. 2 Cumulative fluorescein mass deposition, relative to the mean value in each trial, on the chamber floor for particles with nominal d_a = 3 μ m under natural mixing conditions over 90 min (20 min aerosol release followed by 70 min of deposition). Aerosol was released 0.64 m above the floor at grid point 7C.

FIG. 3 Cumulative fluorescein mass deposition, relative to the mean value in each trial, on the chamber floor for particles with nominal d_a = 14 μ m under natural mixing conditions over 90 min (20 min aerosol release followed by 70 min of deposition). Aerosol was released 0.64 m above the floor at grid point 7C.

FIG. 4 Cumulative fluorescein mass deposition, relative to the mean value in each trial, on the chamber floor for particles with nominal d_a = 3 μ m under forced mixing conditions over 90 min (20 min aerosol release followed by 70 min of deposition). Aerosol was released 0.64 m above the floor at grid point 7C. Mixing was induced by two fans blowing towards each other on the floor in grid point 1D.

FIG. 5 Cumulative fluorescein mass deposition, relative to the mean value in each trial, on the chamber floor for particles with nominal d_a = 14 μ m under forced mixing conditions over 90 min (20 min aerosol release followed by 70 min of deposition). Aerosol was released 0.64 m above the floor at grid point 7C. Mixing was induced by two fans blowing towards each other on the floor in grid point 1D.

TABLE A-1 Mean and fluctuating velocities ((u,v,w), (σ _u ,σ _v ,σ _w )) and mean and fluctuating speed (U _s , σ _s ) from combined anemometry measurements for each location and height in the forced mixing condition. Mixing was induced by two 0.08 m diameter instrument fans blowing towards each other on the floor in grid point 1D

		Mean (cm/s)		Fluctuating (cm/s)
Grid point	Height (m)	(,,)		(σ u ,σ v ,σ w )	σ s
1A	0.18	(1, 4, 2)	9	(3, 5, 4)	5
1B	0.18	(−5, 0, −4)	9	(3, 3, 4)	16
1C	0.18	(−24, −4, −8)	28	(5, 5, 6)	16
1D	0.18	(42, −69, 81)	116	(12, 14, 23)	4
1E	0.18	(22, −6, −3)	25	(3, 4, 3)	15
1F	0.18	(8, −2, −1)	10	(3, 3, 3)	8
1G	0.18	(3, 2, 1)	5	(2, 3, 2)	10
2B	0.18	(−2, −2, −1)	7	(4, 4, 4)	16
2C	0.18	(−12, −13, −5)	22	(8, 6, 6)	15
2D	0.18	(24, 32, 29)	55	(13, 21, 16)	10
2E	0.28	(9, −9, −3)	14	(3, 3, 3)	17
2F	0.18	(6, −3, −1)	9	(3, 3, 2)	12
3B	0.18	(0, 1, −3)	8	(5, 4, 4)	10
3C	0.18	(2, 0, −4)	10	(6, 5, 5)	9
3D	0.18	(0, −4, −3)	8	(4, 3, 4)	19
3E	0.18	(4, −5, −1)	8	(3, 2, 3)	18
3F	0.18	(3, −2, −1)	6	(2, 2, 2)	11
5B	0.18	(5, 5, −1)	10	(4, 4, 4)	6
5D	0.18	(1, 0, 1)	4	(3, 3, 2)	16
5F	0.18	(1, −1, 1)	3	(2, 2, 2)	14
7B	0.18	(3, 6, 0)	8	(3, 3, 3)	8
7D	0.18	(−2, 0, 0)	4	(2, 3, 2)	12
7F	0.18	(−3, −1, 1)	4	(2, 1, 2)	8
9B	0.18	(−3, −2, −1)	5	(2, 2, 2)	6
9D	0.18	(−4, −3, −1)	7	(2, 2, 2)	7
9F	0.18	(−4, −3, 0)	6	(3, 2, 2)	9
1C	0.63	(12, −5, 3)	18	(9, 7, 9)	15
1E	0.63	(7, −3, 2)	10	(3, 3, 3)	15
1F	0.63	(3, −1, 8)	10	(4, 4, 4)	21
2B	0.63	(10, −1, −1)	13	(7, 4, 5)	7
2C	0.63	(19, −5, 5)	24	(9, 7, 8)	11
2E	0.63	(5, −5, 1)	9	(3, 3, 2)	12
2F	0.63	(4, −3, 2)	7	(2, 3, 2)	7
3D	0.63	(4, −3, −4)	9	(4, 4, 4)	12
1A	0.79	(8, 0, 3)	11	(5, 4, 4)	5
1B	0.79	(13, −2, 7)	17	(6, 5, 5)	6
1F	0.79	(0, −2, 1)	7	(3, 4, 5)	4
1G	0.79	(1, −2, 8)	10	(3, 3, 3)	3
2B	0.79	(7, −2, 8)	13	(6, 4, 5)	6
2C	0.79	(16, −3, 9)	22	(8, 7, 8)	8
2E	0.79	(3, −5, 1)	8	(2, 2, 2)	2
2F	0.79	(0, −3, −4)	6	(2, 3, 3)	3
3B	0.79	(2, −2, 4)	8	(3, 3, 6)	4
3D	0.79	(1, −4, −3)	7	(2, 3, 3)	3
3F	0.79	(2, −2, −1)	6	(3, 3, 4)	2
5A	0.79	(−1, 1, −1)	5	(2, 3, 3)	3
5B	0.79	(0, −1, 5)	8	(3, 3, 5)	4
5D	0.79	(2, −2, 1)	6	(3, 2, 5)	3
5F	0.79	(2, −2, 1)	6	(3, 2, 5)	3
5G	0.79	(2, −2, 3)	6	(2, 2, 3)	2
7B	0.79	(0, 1, 3)	6	(3, 2, 5)	3
7D	0.79	(−1, −1, 0)	4	(3, 2, 3)	3
7F	0.79	(0, −1, 3)	5	(2, 2, 4)	3
9A	0.79	(−1, 0, 1)	4	(2, 2, 4)	2
9B	0.79	(−1, 0, 5)	7	(2, 2, 6)	4
9D	0.79	(−2, 0, 4)	6	(2, 2, 4)	3
9F	0.79	(−1, 0, 5)	7	(2, 2, 5)	4
9G	0.79	(0, 0, 8)	9	(2, 2, 3)	3
1A	1.14	(5, 1, 9)	12	(5, 4, 5)	5
1B	1.14	(4, −2, 7)	11	(4, 3, 6)	5
1C	1.14	(5, −2, 4)	10	(5, 4, 6)	5
1E	1.14	(1, −2, −3)	6	(3, 3, 3)	3
1F	1.14	(0, −1, 1)	6	(3, 3, 4)	3
1G	1.14	(−2, 0, 2)	6	(3, 3, 4)	3
2C	1.14	(3, −2, −2)	6	(3, 3, 3)	3
2E	1.14	(3, −2, −3)	6	(2, 2, 2)	2
3B	1.14	(2, −2, 3)	7	(3, 3, 5)	3
3D	1.14	(1, −2, −1)	6	(2, 2, 4)	2
3F	1.14	(2, −1, −2)	6	(3, 3, 4)	3
5A	1.14	(1, 0, 5)	7	(3, 3, 4)	3
5B	1.14	(2, −1, 8)	10	(3, 3, 4)	3
5D	1.14	(2, −1, 2)	7	(3, 2, 6)	4
5F	1.14	(2, −1, 3)	8	(3, 3, 6)	3
5G	1.14	(1, −2, 0)	4	(2, 2, 2)	3
7B	1.14	(1, 0, 10)	11	(3, 2, 4)	4
7D	1.14	(1, −1, 4)	6	(2, 2, 5)	4
7F	1.14	(1, 0, 6)	9	(3, 3, 8)	4
9A	1.14	(2, 0, 11)	11	(3, 3, 4)	3
9B	1.14	(0, 0, 7)	8	(3, 2, 5)	4
9D	1.14	(0, 0, 4)	6	(2, 2, 5)	4
9F	1.14	(0, 0, −1)	6	(3, 3, 5)	3
9G	1.14	(0, 0, 11)	11	(2, 2, 3)	3
1A	1.73	(2, 1, 10)	11	(3, 3, 5)	4
1B	1.73	(1, −1, 7)	9	(3, 3, 5)	4
1C	1.73	(0, −1, 3)	5	(2, 2, 3)	2
1E	1.73	(1, 1, 10)	11	(3, 3, 4)	3
1F	1.73	(0, 3, 5)	8	(3, 3, 5)	4
1G	1.73	(1, 3, 9)	11	(3, 3, 4)	3
2C	1.73	(0, 0, 2)	4	(2, 2, 3)	2
2E	1.73	(2, 0, 4)	7	(3, 2, 4)	3
3B	1.73	(1, −1, 2)	6	(3, 3, 5)	4
3D	1.83	(0, −2, 0)	5	(3, 2, 4)	3
3F	1.73	(1, 1, 0)	6	(3, 3, 5)	3
5A	1.73	(0, 3, −1)	5	(3, 3, 3)	3
5B	1.73	(1, −1, 5)	7	(3, 3, 5)	4
5D	1.73	(1, 0, 3)	7	(3, 3, 5)	4
5F	1.73	(2, 0, 4)	7	(3, 3, 5)	4
5G	1.73	(3, −1, 10)	11	(3, 2, 3)	3
7B	1.73	(1, 0, 5)	9	(3, 3, 7)	4
7D	1.73	(1, 0, 7)	8	(3, 2, 6)	5
7F	1.73	(1, −1, 7)	9	(3, 2, 6)	5
9A	1.73	(0, 1, 0)	5	(2, 3, 4)	3
9B	1.73	(0, 0, 5)	8	(3, 3, 6)	4
9D	1.73	(0, 0, 5)	7	(2, 2, 5)	4
9F	1.73	(0, 0, 6)	7	(2, 2, 5)	4
9G	1.73	(0, 0, 8)	8	(2, 2, 5)	5

TABLE A-2 Comulative fluorescein mass deposited 0.02 m² foil samplers on the chamber walls, relative to the mean value of the cumulative fluorescein mass deposited on chamber floor over 90 min (20 min aerosol release followed by 70 min of deposition under natural mixing). Samplers were centered 1.12 m above the floor, and centered in each wall, lengthwise

	Relative cumulative fluorescein mass
Exp	North	East	South	West
T1	0.00	0.00	0.00	0.00
T2	0.00	0.00	0.00	0.22
T3	0.00	0.01	0.00	0.00
T4	0.00	0.02	0.00	0.00
T6	0.00	0.00	0.00	0.00
T7	0.02	0.00	0.00	0.02

TABLE A-3 Time-weighted-average fluorescein mass concentration (C_TWA) relative to the mean value in each trial, measured at 1.5 m above the floor over 90 min (20 min aerosol release followed by 70 min of deposition) under natural and forced mixing conditions. Aerosol was released 0.64 m above the floor at grid point 7C. Forced mixing was induced by two 0.08 m diameter instrument fans on the floor, blowing towards each other in grid point 1D

	Relative fluorescein mass CTWA
	Natural mixing							Forced mixing
	da ∼ 3 μ m				da ∼ 14 μ m			da ∼ 3 μ m				da ∼ 14 μ m
Grid point	T1	T2	T3	T4	T5	T6	T7	T8	T9	T10	T11	T12	T13	T14
2B	0.96	0.87	1.3	1.4	2.2	1.4	0.84	1.4	0.98	1.1	1.7	0.85	0.64	0.77
2D	1.1	1.4	1.2	0.29	1.8	1.3	1.3	0.44	0.65	1.1	0.70	0.61	0.64	0.98
2F	0.72	1.4	0.90	0.53	1.3	0.87	1.0	1.2	1.5	1.2	1.7	0.68	0.97	0.75
4B	0.46	1.0	1.0	1.4	2.6	2.5	1.7	1.2	1.4	0.66	1.3	0.95	0.76	0.46
4D	0.85	1.1	0.89	0.87	1.5	0.80	1.2	0.65	0.87	0.93	0.43	0.58	0.76	0.99
4F	1.0	1.1	0.85	1.4	0.83	0.47	0.56	1.0	0.94	1.2	0.80	0.75	0.84	0.51
6B	0.98	0.77	1.4	0.56	1.1	1.9	1.7	1.1	0.75	0.66	1.26	1.8	0.96	0.68
6D	0.86	0.60	1.2	0.60	0.37	0.76	0.91	1.0	0.61	1.2	0.86	2.1	1.4	2.3
6F	1.3	0.96	0.36	0.98	0.09	0.46	0.72	1.5	1.0	0.78	0.48	0.76	0.94	0.68
8B	0.98	1.3	1.3	1.7	0.16	0.65	0.19	0.83	0.41	1.03	0.95	1.3	1.1	1.5
8D	1.2	0.91	0.88	1.5	0.12	0.64	0.68	1.2	1.2	0.93	0.95	1.0	1.8	1.6
8F	1.6	0.51	0.72	0.89	0.09	0.33	1.2	0.55	1.6	1.1	0.93	0.56	1.2	0.72
CV (%)	28	29	30	45	87	65	45	33	38	20	41	51	34	55