Coalescence of two nanoscopic argon droplets by phase-field modeling (doi:10.18419/darus-2456)

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Part 1: Document Description
Part 2: Study Description
Part 3: Data Files Description
Part 4: Variable Description
Part 5: Other Study-Related Materials
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Document Description

Citation

Title:

Coalescence of two nanoscopic argon droplets by phase-field modeling

Identification Number:

doi:10.18419/darus-2456

Distributor:

DaRUS

Date of Distribution:

2022-02-04

Version:

1

Bibliographic Citation:

Hoffmann, Marco; Diewald, Felix; Langenbach, Kai, 2022, "Coalescence of two nanoscopic argon droplets by phase-field modeling", https://doi.org/10.18419/darus-2456, DaRUS, V1, UNF:6:aSSyMvbguQioQHMdsX/qhw== [fileUNF]

Study Description

Citation

Title:

Coalescence of two nanoscopic argon droplets by phase-field modeling

Identification Number:

doi:10.18419/darus-2456

Authoring Entity:

Hoffmann, Marco (Technische Universität Kaiserslautern)

Diewald, Felix (Fraunhofer ITWM)

Langenbach, Kai (Universität Innsbruck)

Date of Production:

2021-04-15

Grant Number:

01IH16008

Distributor:

DaRUS

Access Authority:

Langenbach, Kai

Access Authority:

Heinen, Matthias

Depositor:

Heinen, Matthias

Date of Deposit:

2022-01-20

Holdings Information:

https://doi.org/10.18419/darus-2456

Study Scope

Keywords:

Engineering, Physics, Computational Fluid Dynamics (CFD), Phase-field, Computer Simulation, Droplet Coalescence, Argon, Lennard-Jones Truncated and Shifted (LJTS)

Topic Classification:

Coalescence

Abstract:

Coalescence of argon droplets with a radius of R=25, 50 and 100 nm was studied with computational fluid dynamics (CFD). The constitutive equations for the CFD simulations were derived from a phase-field model coupled to the Navier-Stokes equations. Therein, the thermodynamics of the fluid were incorporated by an equation of state for the Lennard-Jones truncated and shifted fluid based on perturbation theory (PeTS), along with the influence parameter, expressing the density and density gradient dependent part of a Helmholtz energy functional. Moreover, an expression for the viscosity and the surface tension for adjusting the influence parameter were needed. Surrounded by coexisting vapor, the droplets were initialized with a distance of approximately a single argon molecule diameter. The coalescence process was studied under isothermal conditions at a temperature of T=110 K.<br> To save computational resources, a interface widening approach was used to perform the calculations on a coarser grid, while keeping the correct physics.<br><br> Data of the coalescing droplets’ interface contours are stored in *.csv files, compressed as *.tar.xz archives that can be found in the contour/ subdirectories (Tree view). One *.csv file contains the data for a single interface contour described by spatial coordinate pairs x [nm] and r [nm] at the time instance t [ps] indicated by the time stamp in the file name, e.g.: *_t000000100.csv => t=100 ps.<br> The archive "early.tar.xz" contains data for the "early" stages of the coalescence process with fine time resolution (1 ps) and the archive "full.tar.xz" contains data for the "full" process with coarser time resolution (10, 20 and 40 ps for R=25, 50 and 100 nm).<br> A simple python script to plot coalescing droplets contours from the *.csv is provided in the subdirectory python/ (Tree view). It will generate contour plots and save them as *.pdf files. Additionally, a sequence of all contours will be created by merging the *.pdf files to a single file.<br><br> Extracted from the interface contours, the evolution of the bridge radius r_b [nm] as well as back of drop positions x_bdl [nm] (left) and x_bdr [nm] (right) over time t [ns] can be found in the *_evo.tab files.

Notes:

All data were stored as *.csv files with ',' used as separator character. Although the DaRUS database system converted these files to the *.tab format, they can be downloaded in the original file format.<br><br> The data set provided for R=100nm was obtained from a simulation employing the interface widening approach with a four times broader interface compared to the true extent under equilibrium conditions.<br> The data provided for R=25 and 50 nm were obtained from simulations without employing the interface widening approach.<br><br> Data sets for the droplets with initial radius R=25, 50 and 100 nm are organized in the subdirectories R25nm/, R50nm/ and R100nm/ (Tree view).

Methodology and Processing

Sources Statement

Data Access

Notes:

Please contact the SFB-TRR75 data admin!

Other Study Description Materials

File Description--f90823

File: PF_R100nm_evo.tab

  • Number of cases: 406

  • No. of variables per record: 4

  • Type of File: text/tab-separated-values

Notes:

UNF:6:nBNm6Hji3EtHrsosSl2FaQ==

File Description--f90825

File: PF_R25nm_evo.tab

  • Number of cases: 505

  • No. of variables per record: 4

  • Type of File: text/tab-separated-values

Notes:

UNF:6:uasOL1+AVtwQJeCT8kVkTw==

File Description--f90828

File: PF_R50nm_evo.tab

  • Number of cases: 529

  • No. of variables per record: 4

  • Type of File: text/tab-separated-values

Notes:

UNF:6:NcgG3JgCLYhvxqJ2sujqtA==

Variable Description

List of Variables:

Variables

t

f90823 Location:

Summary Statistics: Max. 82.086; Min. 0.0; Mean 20.92527586206897; StDev 26.57770394327831; Valid 406.0

Variable Format: numeric

Notes: UNF:6:mYGbXo1c0Wis5BMUePsUSA==

r_b

f90823 Location:

Summary Statistics: Mean 68.81113376752721; Min. 0.3532916661014001; StDev 51.04382767705907; Max. 142.7068244963254; Valid 406.0;

Variable Format: numeric

Notes: UNF:6:SkkyiWg7x+sYS/3pEqIqRQ==

x_bdl

f90823 Location:

Summary Statistics: Valid 406.0; Min. -200.1662249815828; Mean -169.8964762736726; StDev 38.295064141615825; Max. -94.09098497550778

Variable Format: numeric

Notes: UNF:6:29mH/fSyRLkD88aNsBR+9A==

x_bdr

f90823 Location:

Summary Statistics: Max. 200.16622454915085; Min. 94.09098497550778; Valid 406.0; StDev 38.29506392090573; Mean 169.89647595369553

Variable Format: numeric

Notes: UNF:6:RIi6sSY9PsrTMLILs14+Ag==

t

f90825 Location:

Summary Statistics: Max. 10.839; StDev 2.6080264830766877; Valid 505.0; Mean 1.3293782178217823; Min. 0.0

Variable Format: numeric

Notes: UNF:6:2HgPrZbFImsq8f3MTAMiHA==

r_b

f90825 Location:

Summary Statistics: Max. 33.31393471324308; Min. 0.1766458338986; Mean 12.999928269344855; StDev 8.9315130934794; Valid 505.0

Variable Format: numeric

Notes: UNF:6:wuD5ZjC+0+GwTycJRgZCmg==

x_bdl

f90825 Location:

Summary Statistics: StDev 6.98126096590391; Valid 505.0; Mean -47.003007321897755; Min. -50.18106078520108; Max. -27.849394048137345

Variable Format: numeric

Notes: UNF:6:ctwnM6WbIg5mQRNNWGp5VA==

x_bdr

f90825 Location:

Summary Statistics: Mean 47.00300739726746; StDev 6.981261004147236; Min. 27.849394080019287; Max. 50.18106087909006; Valid 505.0

Variable Format: numeric

Notes: UNF:6:9DnBMhpFRVf0nc3u5jSgJg==

t

f90828 Location:

Summary Statistics: Mean 3.3353383742911147; StDev 6.643020451895443; Min. 0.0; Valid 529.0; Max. 25.87

Variable Format: numeric

Notes: UNF:6:z+NiGyDLnztMW63hOA2Sww==

r_b

f90828 Location:

Summary Statistics: Min. 0.1766458338986; Mean 22.68860831471221; Valid 529.0; StDev 20.623845743827168; Max. 69.11730164517847;

Variable Format: numeric

Notes: UNF:6:rH4S3nodHnDS0NerqvpB9Q==

x_bdl

f90828 Location:

Summary Statistics: Min. -100.16874966354078; StDev 14.731693488602739; Max. -50.854384962576596; Mean -93.19667821038568; Valid 529.0

Variable Format: numeric

Notes: UNF:6:6W71qsiAni7q+asp6pI2CA==

x_bdr

f90828 Location:

Summary Statistics: Valid 529.0; Mean 93.19667821767224; StDev 14.731693491920048; Max. 100.16874965745696; Min. 50.854384962576596

Variable Format: numeric

Notes: UNF:6:jdQmlzjOCQvcqXlTZPjmYQ==

Other Study-Related Materials

Label:

coal_contour_sequence.py

Text:

Simple python script to plot coalescing droplets contours from *.csv files and save them as *.pdf files. Additionally, a sequence of all contours is created by merging the *.pdf files to a single file.

Notes:

text/x-python

Other Study-Related Materials

Label:

early.tar.xz

Text:

Archive containing interface contours of the "early" stages of the droplet coalescence process as *.csv files with fine time resolution. One *.csv file contains the data for a single interface contour described by the spatial coordinates x [nm] and r [nm] at the time instance t [ps] indicated by the time stamp in the file name, e.g.: *_t000000100.csv => t=100 ps.

Notes:

application/x-xz

Other Study-Related Materials

Label:

full.tar.xz

Text:

Archive containing "full" sequence of droplet coalescence interface contours as *.csv files with coarse time resolution. One *.csv file contains the data for a single interface contour described by the spatial coordinates x [nm] and r [nm] at the time instance t [ps] indicated by the time stamp in the file name, e.g.: *_t000000100.csv => t=100 ps.

Notes:

application/x-xz

Other Study-Related Materials

Label:

early.tar.xz

Text:

Archive containing interface contours of the "early" stages of the droplet coalescence process as *.csv files with fine time resolution. One *.csv file contains the data for a single interface contour described by the spatial coordinates x [nm] and r [nm] at the time instance t [ps] indicated by the time stamp in the file name, e.g.: *_t000000100.csv => t=100 ps.

Notes:

application/x-xz

Other Study-Related Materials

Label:

full.tar.xz

Text:

Archive containing "full" sequence of droplet coalescence interface contours as *.csv files with coarse time resolution. One *.csv file contains the data for a single interface contour described by the spatial coordinates x [nm] and r [nm] at the time instance t [ps] indicated by the time stamp in the file name, e.g.: *_t000000100.csv => t=100 ps.

Notes:

application/x-xz

Other Study-Related Materials

Label:

early.tar.xz

Text:

Archive containing interface contours of the "early" stages of the droplet coalescence process as *.csv files with fine time resolution. One *.csv file contains the data for a single interface contour described by the spatial coordinates x [nm] and r [nm] at the time instance t [ps] indicated by the time stamp in the file name, e.g.: *_t000000100.csv => t=100 ps.

Notes:

application/x-xz

Other Study-Related Materials

Label:

full.tar.xz

Text:

Archive containing "full" sequence of droplet coalescence interface contours as *.csv files with coarse time resolution. One *.csv file contains the data for a single interface contour described by the spatial coordinates x [nm] and r [nm] at the time instance t [ps] indicated by the time stamp in the file name, e.g.: *_t000000100.csv => t=100 ps.

Notes:

application/x-xz