Thermodynamics and Process Modelling
The Thermodynamics and Process Modelling Group of the NPL
Materials Centre provides good quality thermodynamic data for an
extensive range of material types including light alloys,
steels, ceramics, glasses, slags,
mattes, salts, polymers, aqueous
solutions and gases. These data can be used to predict
the chemical species and phases likely to form at equilibrium in the
types of system of greatest industrial interest - those containing
large numbers of chemical elements - and so provide a valuable guide
to the solution of many industrial problems. Organisations can lease
these databases and MTDATA for in-house
use or ask for calculations to be done at NPL.
Provision of thermodynamic databases
A range of high
quality thermodynamic databases
is available for lease. Consistent reference states are used
throughout these databases so that they can be combined to explore
systems containing many different phase types, for example
A consultancy service is available which
allows companies, whether large or small, to make use of the
expertise within the Thermodynamics and Process Modelling Group in
applying thermodynamic data to the solution of practical problems.
Thermophysical and thermodynamic properties of Ni base superalloys
NPL is currently involved in various projects which require the development of a thermodynamic database
for Ni base superalloys. The main vehicle for this is in support of the development of a capability at
NPL to measure accurately temperatures and enthalpies of transitions for high temperature materials using
a single pan technique. The database development also supports a Technology Strategy Board project "Improved Modelling of
Material Properties for Advanced Power Plant" which has the ultimate aim of developing new improved materials and
increase the utilisation of power plant through a better understanding of degradation mechanisms. This will
be achieved through integration of various material modelling techniques from nano scale through to macro
scale. This work also feeds into the
IMPRESS European FP6 project concerned with the development of new intermetallic alloys for industrial
applications such as gas turbine blades and hydrogen fuel cells. Ultimately the thermodynamic database
will be available commercially in conjunction with MTDATA and the Virtual Measurement System.
In support of a related project on measuring thermophysical properties for lightweight alloys, NPL is also
developing a thermodynamic database for Mg alloys.
NPL is currently investigating methods of linking software for the calculation of materials chemistry
(such as MTDATA) to third party CFD (Computational Fluid Dynamics) packages in order to study systems where there
are significant temperature and concentration gradients.
Molecular Dynamics, in principle, provides a mechanism for calculating thermodynamic properties from force
field data. NPL is looking into methods where this could be applicable in order to provide data where
experimental data are lacking or difficult to obtain eg developing equations of state for real gases or measurement
of the enthalpies of mixing in ionic melts.
NPL is currently involved in attempting to validate ab initio
techniques against the best available experimental and critically assessed thermodynamic data
for gaseous and condensed phases. NPL is aiming to work with existing users of such software
and software developers to identify and understand any glaring discrepancies.
NPL is currently developing software packages for
modelling transient heat transfer, taking account
of changes in material properties with changes in temperature and phase. TherMOL 3D and MTDATA have been
successfully linked and is able to model complex multi-material structures subjected to various heat transfer
training and support
The group is responsible for the
development and support of MTDATA, a powerful
and user-friendly software and data package for the prediction of
phase equilibria in systems containing large numbers of chemical
elements. MTDATA is leased to industrial, government and academic
organisations worldwide and training
courses are held regularly at NPL.
A programming interface is
available which allows MTDATA users to set up phase equilibrium
calculations and process their results directly from within their
own or other commercial software. Calculations can be tailored to
specific industrial applications in this way either by customising
output or by using equilibrium calculations as part of a
non-equilibrium process model. Organisations are able to write
"application software" in-house or ask for this to done at NPL.
The Materials Algorithm Project (MAP) aims to
provide a library of subroutines, written in FORTRAN, to be used
as a foundation for "application software" of this kind.
For further information about the services offered by the
Thermodynamics and Process Modelling Group please contact Hugh