Novel test section for homogeneous nucleation studies in a pulse expansion wave tube: experimental verification and gasdynamic 2D numerical model

Campagna, M. M.; Dongen, M. E. H. van; Smeulders, David

doi:10.1007/s00348-020-02945-3

Cited by 4 publications

(6 citation statements)

References 14 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…A novel design of a Pulse Expansion Wave Tube (PEWT) for the study of homogeneous nucleation in mixtures of vapors and gases was presented by Campagna et al [10].…”

Section: Methodsmentioning

confidence: 99%

Experimental investigation of homogeneous nucleation of water in various gases using an expansion chamber

2022

View full text Add to dashboard Cite

Nucleation is an integral part of phase transitions and plays an important role in technology. The control of nucleation in devices such as turbines, rocket and jet engines, wind tunnels, and combustion processes is key to achieving efficient, ecologically sound operation. Our paper presents information about a modernized experimental setup used for homogeneous water nucleation research. The main goal of the study is an analysis of the influence of carrier gas on homogeneous nucleation. The experimental setup based on an expansion chamber has been used for research of homogeneous nucleation over several decades and has undergone various technical improvements. In the Institute of Thermomechanics, the setup was been completely disassembled and cleaned. Pressure transducers, laser, and the data acquisition system have been replaced with modern parts. After that, the chamber was assembled, and thoroughly tested and calibrated. Our investigations were carried with argon and nitrogen as carrier gases in a range of nucleation temperatures 220 – 260 K, pressure range 80-150 kPa, at several concentrations of water vapour. The results thus obtained are consistent with literature data. The findings suggest that this experimental approach is useful for homogeneous water nucleation research.

show abstract

“…A novel design of a Pulse Expansion Wave Tube (PEWT) for the study of homogeneous nucleation in mixtures of vapors and gases was presented by Campagna et al [10].…”

Section: Methodsmentioning

confidence: 99%

Experimental investigation of homogeneous nucleation of water in various gases using an expansion chamber

2022

View full text Add to dashboard Cite

show abstract

“…A schematic of the facility is reported in Fig. 1 (more geometrical details in Campagna et al 2020b). The PEWT is a special shock tube ( Looijmans and van Dongen 1997) implementing the nucleation pulse method (Peters 1983).…”

Section: Experimental Methodology Overviewmentioning

confidence: 99%

“…The PEWT is a special shock tube ( Looijmans and van Dongen 1997) implementing the nucleation pulse method (Peters 1983). This technique enables an effective decoupling of nucleation and droplet growth phenomena, which generates an almost monodisperse cloud of growing clusters/droplets (Campagna et al 2020b). The number of critical clusters per unit of time and volume J (nucleation rate) is experimentally determined as J = n d ∕ t , with n d the droplet number density and t the nucleation pulse duration.…”

Section: Experimental Methodology Overviewmentioning

confidence: 99%

“…By means of the optical setup, Constant Angle Mie Scattering CAMS (Wagner and Strey 1981;Wagner 1985;Strey et al 1994) is applied and n d can be determined. The nucleation pulse duration t is obtained from the pressure signal, which is measured at the test section wall of the PEWT with two pressure transducers (Campagna et al 2020b). The temperature T at the pulse condition is determined by measuring the initial temperature of the test section wall and assuming isentropic expansion (Campagna et al 2020a).…”

Section: Experimental Methodology Overviewmentioning

confidence: 99%

“…The Pulse Expansion Wave Tube (PEWT) allows to study homogeneous nucleation by experimental means at temperatures ranging from 220 K to 260 K( Campagna et al 2020b). The temperature range is limited to avoid the formation of ice crystals (for T< 220K) and by PEWT gas dynamics constraints (for T < 260 K).…”

mentioning

confidence: 99%

See 2 more Smart Citations

Critical cluster composition from homogeneous nucleation data: application to water in carbon dioxide–nitrogen carrier gases

et al. 2021

Self Cite

View full text Add to dashboard Cite

Knowledge on critical cluster composition is important for improving the nucleation theory. Thus, homogeneous water nucleation experiments previously carried out in nitrogen and 0%, 5%, 15% and 25% of carbon dioxide ( Campagna et al. 2020a, 2021) are analyzed. The tests were conducted at 240 K and 0.1 MPa, 1 MPa and 2 MPa. The observed nucleation rates are strongly dependent on supersaturation, pressure, temperature and mixture composition. These experimentally found dependencies can be used to derive the composition of critical clusters by means of the nucleation theorem. In this way, a macroscopic quantity, nucleation rate, reveals properties of critical clusters consisting of a few tens of molecules. Two novel methods are presented for the detailed application of the nucleation theorem. The first method extends to mixtures of $$\,\,\,\,\,\,\,N>2\,\,\,\,\,\,$$ N > 2 components the approach used in literature for two components. The second method not only applies to $$N>2$$ N > 2 mixtures in a more straightforward manner, but it can also be used for unary as well as for binary and multi-component nucleation cases. To the best of our knowledge, for the first time the critical cluster composition is computed for high pressure nucleation data of a vapor (here water) in mixtures of two carrier gases (here carbon dioxide–nitrogen). After a proper parameterization of the nucleation rate data, both methods consistently lead to the same critical nuclei compositions within the experimental uncertainty. Increasing pressure and carbon dioxide molar fraction at fixed supersaturation leads to a decrease in the water content of the critical cluster, while the adsorbed number of nitrogen and carbon dioxide molecules increases. As a consequence, the surface tension decreases. This outcome explains the observed increase in the nucleation rate with increasing pressure and carbon dioxide molar fraction at constant supersaturation. Graphic abstract

show abstract

Homogeneous water nucleation: Experimental study on pressure and carrier gas effects

Campagna

Hrubý

Dongen

et al. 2020

The Journal of Chemical Physics

View full text Add to dashboard Cite

Homogeneous nucleation of water is investigated in argon and in nitrogen at about 240 K and 0.1 MPa, 1 MPa, and 2 MPa by means of a pulse expansion wave tube. The surface tension reduction at high pressure qualitatively explains the observed enhancement of the nucleation rate of water in argon as well as in nitrogen. The differences in nucleation rates for the two mixtures at high pressure are consistent with the differences in adsorption behavior of the different carrier gas molecules. At low pressure, there is not enough carrier gas available to ensure the growing clusters are adequately thermalized by collisions with carrier gas molecules so that the nucleation rate is lower than under isothermal conditions. This reduction depends on the carrier gas, pressure, and temperature. A qualitative agreement between experiments and theory is found for argon and nitrogen as carrier gases. As expected, the reduction in the nucleation rates is more pronounced at higher temperatures. For helium as the carrier gas, non-isothermal effects appear to be substantially stronger than predicted by theory. The critical cluster sizes are determined experimentally and theoretically according to the Gibbs–Thomson equation, showing a reasonable agreement as documented in the literature. Finally, we propose an empirical correction of the classical nucleation theory for the nucleation rate calculation. The empirical expression is in agreement with the experimental data for the analyzed mixtures (water–helium, water–argon, and water–nitrogen) and thermodynamic conditions (0.06 MPa–2 MPa and 220 K–260 K).

show abstract

Novel test section for homogeneous nucleation studies in a pulse expansion wave tube: experimental verification and gasdynamic 2D numerical model

Cited by 4 publications

References 14 publications

Experimental investigation of homogeneous nucleation of water in various gases using an expansion chamber

Experimental investigation of homogeneous nucleation of water in various gases using an expansion chamber

Critical cluster composition from homogeneous nucleation data: application to water in carbon dioxide–nitrogen carrier gases

Homogeneous water nucleation: Experimental study on pressure and carrier gas effects

Contact Info

Product

Resources

About