Laboratory study of H₂SO₄/H₂O nucleation using a new technique – a laminar co-flow tube

Figures & data

Fig. 1. A schematic description of the experimental setup, including the laminar co-flow tube.

Fig. 2. The mixture preparation device consists of three saturators where the stream of the carrier gas is saturated with the desired vapour.

Fig. 3. A detailed depiction of the inner layout in the saturators used in the mixture preparation device.

Table 1. Verified temperature range and maximal flow rate allowing stable and repeatable saturated vapour generation in the saturator.

Media	$\dot{Q}$ [l min^−1]	Tsat [°C]
Water	2	20 ÷ 65
Sulphuric acid	0.25	20 ÷ 65

Note: The temperature limits are related to used thermostating equipment, the saturator itself is designed for 100 °C.

Fig. 4. A detailed description of the design of the laminar co-flow tube.

Table 2. Parameters used in the experimental set up and the corresponding results, p_atm = 101.325 kPa.

Tsat [°C]	Tchamb [°C]	${\dot{Q}}_{\text{W}}$	${\dot{Q}}_{\text{SA}}$	N [# cm^−3]
		[l min^−1]	[l min^−1]
22.53	24.78	0.78	0.25	4.72
22.34	25.09	0.77	0.25	6.17
22.36	24.49	0.76	0.25	6.53
21.82	24.86	0.75	0.25	16.73
23.21	22.81	0.74	0.25	8.73
22.88	25.13	0.73	0.25	48.17
23.50	24.82	0.72	0.25	27.70
22.11	24.76	0.71	0.25	8.88
22.05	25.03	0.70	0.25	12.10
23.37	25.09	0.69	0.25	9.14

Fig. 5. Postprocessing of measured concentrations, T_sat = 22.47 [°C], ${\dot{Q}}_{\text{W}}$ = 0.76 [l min^–1], ${\dot{Q}}_{\text{SA}}$ = 0.25 [l min^–1].

Table 3. Deviations caused by different setting of limit concentration N_limit, T_sat = 22.47 [°C], ${\dot{Q}}_{\text{W}}$ = 0.76 [l min⁻¹], ${\dot{Q}}_{\text{SA}}$ = 0.25 [l min⁻¹].

Nlimit [# cm^−3]	Naverage [# cm^−3]	Deviation from the whole data-set (Nlimit = 1000) [%]
100	4.67	–28.55
200	5.20	–20.48
300	5.72	–12.53
400	5.87	–10.22
500	5.97	–8.61
600	5.97	–8.61
700	6.31	–3.40
800	6.31	–3.40
900	6.31	–3.40
1000	6.53	0.00

Table 4. Results obtained by CFD simulations, p_atm = 101.325 kPa, coordinate of nucleation maximum on the axis of the co-flow section x = 0.53 cm.

${\dot{Q}}_{\text{W}}$	$J_{\text{theor}}^{max}$	$J_{\text{exp}}^{max}$	Ra	Rh	[H2SO4]^Rh33	$J_{\text{exp}}^{Rh33}$
[l min^−1]	[cm^−3 s^−1]	[cm^−3 s^−1]	[–]	[–]	[cm^−3]	[cm^−3 s^−1]
0.78	2.80 × 10^12	7.47 × 10^1	0.62	0.45	3.38 × 10^11	1.11 × 10^1
0.77	7.25 × 10^11	9.52 × 10^1	0.58	0.44	3.37 × 10^11	2.95 × 10^1
0.76	4.73 × 10^12	1.00 × 10^2	0.63	0.46	3.40 × 10^11	1.70 × 10^1
0.75	2.43 × 10^11	2.47 × 10^2	0.55	0.42	2.41 × 10^11	1.80 × 10^0
0.74	2.43 × 10^14	1.32 × 10^2	0.75	0.50	3.42 × 10^11	1.14 × 10^1
0.73	2.63 × 10^12	6.95 × 10^2	0.61	0.45	3.56 × 10^11	1.31 × 10^2
0.72	3.20 × 10^13	3.98 × 10^2	0.69	0.48	3.94 × 10^11	5.48 × 10^1
0.71	8.47 × 10^11	1.22 × 10^2	0.59	0.44	3.28 × 10^11	3.93 × 10^1
0.70	3.56 × 10^11	1.64 × 10^2	0.56	0.43	2.65 × 10^11	2.58 × 10^0
0.69	6.88 × 10^11	1.22 × 10^2	0.58	0.43	2.95 × 10^11	4.86 × 10^0

Fig. 6. Comparison of our results with data obtained by other authors using different types of experimental devices. The dependence of the experimental nucleation rate on the concentration of sulphuric acid in the chamber during the constant value of Rh. Uncertainties of experimental data obtained by LCFT are marked.

Table 5. Values of coefficients used in Equation (A2(A1) $$p_{\text{sat}}=133.332\times {10}^Z,$$(A1) ).

a = 19.301142

b = 2892.3693

c = 2.892736

d = –4.9369728 × 10^–3

e = 5.606905 × 10^–6

f = –4.645869 × 10^–9

g = 3.7874 × 10^–12

Table 6. Properties of sulphuric acid.

M = 9.81 ⋅ 10^–2		[kg mol^−1]
$D_{\text{SA},\text{N}2}=0.2094·{10}^{-4}{\left(\frac{T}{298.15}\right)}^{1.75}/\left(\frac{p}{101.325}\right)$	Ayers et al. (1980)	[m^2 s^−1]

Table 7. Properties of water vapour.

M = 1.80 × 10^–2		[kg mol^−1]
$D_{\text{SA},\text{N}2}=0.2061\times {10}^{-4}{\left(\frac{T}{273.15}\right)}^{2.031}/\left(\frac{p}{101.325}\right)$	O’Connell et al. (1969)	[m^2 s^−1]

Table 8. Properties of nitrogen T_chamb = 25 °C and p_atm = 101.325 kPa.

M = 2.80 × 10^–2 [kg mol^−1]

R = 8.314 × 10^3 [J kmol^−1 K^−1]

ρ = 1.145 [kg m^−3]

η = 17.9 × 10^–6 [Pa s]

Ayers, G. P., Gillett, R. W. and Gras, J. L. 1980. On the vapor pressure of sulfuric acid. Geophys. Res. Lett. 7, 433–436.10.1029/GL007i006p00433

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