Physical Modeling for Virtual Manufacturing Systems and Processes

Computational Molecular Engineeringfor Engineering Thermodynamics

Kick-off MeetingInternational Research Training Group 2057

Martin Horsch and Hans Hasse

TU KaiserslauternEngineering Thermodynamics (LTD)

Davis, California, October 8, 2014

2 Oct 8, 2014Physical Modeling for Virtual Manufacturing Systems and Processes

Laboratory of Engineering Thermodynamics (LTD)

Thermodynamic Properties

Process Thermodynamics

Biothermodynamics

Molecular Thermodynamics

Since April 2008, the Laboratory of Engineering Thermodynamics (LTD)is directed by Prof. Dr.-Ing. Hans Hasse. Our research activities cover all areas of thermodynamics:

3 Oct 8, 2014Physical Modeling for Virtual Manufacturing Systems and Processes

Process Design and Raw Material Change

Jun. Prof. Dr.-Ing. Jakob Burger

• Multi-criteria optimization of chemical processes based on Pareto sets

• Assessment and comparison of value-added chains

• Decision support for the chemical industry

raw-material costs

investment

energyefficiencysustainability,

health and safety

productquality

4 Oct 8, 2014Physical Modeling for Virtual Manufacturing Systems and Processes

Chemical Systems Engineering

Jun. Prof. Dr.-Ing. Erik von Harbou

• Modeling and simulation of complex reacting multi-phase systems

• Model-based design of experiments and uncertainty quantification

• NMR spectroscopy for process and reaction monitoring

5 Oct 8, 2014Physical Modeling for Virtual Manufacturing Systems and Processes

Computational Molecular Engineering

From Physics(qualitative accuracy)

To Engineering(quantitative reliability)

• Physically realistic modeling of intermolecular interactions

• Separate contributions due to repulsive and dispersive as well as electrostatic interactions

• No blind fitting, but parameters of effective pair potentials are adjusted to experimental data

• Physical realism facilitates reliable interpolation and extrapolation

6 Oct 8, 2014Physical Modeling for Virtual Manufacturing Systems and Processes

Molecular models of real fluids

Geometry

Bond lengths and angles

Molecular modeling

Dispersion and repulsion

Lennard-Jones potential:Size and energy parameters

7 Oct 8, 2014Physical Modeling for Virtual Manufacturing Systems and Processes

Molecular models of real fluids

Geometry

Bond lengths and angles

Electrostatics

Point polarities (charge, dipole, quadrupole):Position and magnitude

Dispersion and repulsion

Lennard-Jones potential:Size and energy parameters

Molecular modeling

8 Oct 8, 2014Physical Modeling for Virtual Manufacturing Systems and Processes

Simulation of bulk fluid properties with the ms2 program

Molecular modeling

Sim

ula

tio

n

ms2 is freely available for academic use – register at http://www.ms-2.de/

Vapor-liquid equilibria: Saturated densities and vapor pressures

T /

K

ρ / mol l-1 T-1 / K-1

log

P*

10-3 / mol m-320 25 30 35

104

s / P

a s

0.0

0.5

1.0

1.5

2.0

2.5

3.0

3.5N2O2CO2

Shear viscosity

10-3 ρ / mol m-310-3 / mol m-3

5 10 15 20 25

104 D

/ m

ol m

-1s-1

0

1

2

3

4

5CO2

C2H6

C2H4

Self-diffusion coefficient

10-3 ρ / mol m-310-3 / mol m-3

20 22 24 26 28 30

102

/

Wm

-1K

-1

0

5

10

15

20

Thermal conductivity

10-3 ρ / mol m-3

102

λ / W

m-1

K-1

Second virial coefficient

B /

cm3

mol

-1

T / K

9 Oct 8, 2014Physical Modeling for Virtual Manufacturing Systems and Processes

Large-scale MD simulation with the ls1 mardyn program

Molecular modeling

Sim

ula

tio

n

l arge s ystems 1 : molecul ar dyn amics

MD world record:

N = 4 x 1012

10 Oct 8, 2014Physical Modeling for Virtual Manufacturing Systems and Processes

Large-scale MD simulation with the ls1 mardyn program

Molecular modeling

Sim

ula

tio

n

released asfree software

(BSD license)

Download ls1 mardyn at www.ls1-mardyn.de

11 Oct 8, 2014Physical Modeling for Virtual Manufacturing Systems and Processes

Molecular dynamics simulation of nucleation processes

Molecular modeling

Pro

cess

es

Sim

ula

tio

n

Yasuoka-Matsumoto method:

• Canonical MD simulation• Limited time interval for nucleation• Conditions change over time

12 Oct 8, 2014Physical Modeling for Virtual Manufacturing Systems and Processes

Non-equilibrium MD simulation of nucleation processes

Molecular modeling

Pro

cess

es

Sim

ula

tio

n

Constant conditions of the supersaturated vapor

Yasuoka-Matsumoto method:

• Canonical MD simulation• Limited time interval for nucleation• Conditions change over time

Alternative approach:

• Grand-canonical MD simulation

13 Oct 8, 2014Physical Modeling for Virtual Manufacturing Systems and Processes

Non-equilibrium MD simulation of nucleation processes

Molecular modeling

Pro

cess

es

Sim

ula

tio

n

Constant conditions of the supersaturated vapor

Yasuoka-Matsumoto method:

• Canonical MD simulation• Limited time interval for nucleation• Conditions change

Alternative approach:

• Grand-canonical MD

14 Oct 8, 2014Physical Modeling for Virtual Manufacturing Systems and Processes

Molecular simulation of fluids at interfaces

Molecular modeling

Inte

rfac

es

Pro

cess

es

Sim

ula

tio

n

● Adsorption (fluid-fluid and fluid-solid)

● Vapor-liquid surface tension

● Curved vapor-liquid interfaces

● Contact angle and contact line pinning

● Nucleation in supersaturated vapors

CO2

O2+

T*

γ*

surface tension ofthe 2CLJQ model

L* = 0.2Q* = 1.41

L* = 0.6Q* = 1.41

Q* = 0

Q* = 1.41

Q* = 2L* = 0.4

15 Oct 8, 2014Physical Modeling for Virtual Manufacturing Systems and Processes

Thermodynamics and Computational Molecular Engineering

Simulation

• ms2 and ls1

• Scale-bridgingMD simulation

• Complexmorphologies

Processes

• NEMD simul-ation methods

• Nanofluidics

• Vapor-liquidnucleation

Interfaces

• Curvature andmorphology

• Adsorption and wetting

• Fluctuations

Thermodynamics

Quantitatively reliable molecular modeling