# Material database

The material database in Dyssol stores physical properties and compound information.

You can find the database structure in the figure below. The compound properties can be constant or T(temperature), P(pressure)-dependent. The dependent properties can be calculated using correlations.

## DMDB file

You can find the file `Materials.dmdb`

in your installation folder, which stores global list of **materials** and their **parameters**. Typical examples in current database are air, coal, sand, urea and water.

You can extend this database by defining your own new materials using the *Tools* menu bar → *Materials database*, which opens the *compounds editor* and enables you to set new compounds.

## Constant parameters

Not all properties have influence on internal calculations. State of aggregation can be used to define several aggregation states of the same material. These parameters can be accessed through units and material streams.

Constant parameters in Dyssol consist of:

Critical pressure

Critical temperature

Heat of fusion

Heat of vaporization

Molar mass: mandatory for simulation, since many parameters are calculated based on it

Normal boiling point

Normal freezing point

Reactivity type

Formation enthalpy

State of aggregation: represented by different numbers. 0 for solid, 1 for liquid, 2 for gas, 3 for unknown

User defined properties

## Dependent parameters

Like constant parameters, temperature- and/or pressure-dependent (TPD) parameters can also be accessed through units and material streams.

Dependent parameters in Dyssol consist of:

Density: mandatory for simulation, since it participates in PSD transformations and T-equilibrium

Enthalpy: mandatory for simulation, since it participates in T-equilibrium

Thermal conductivity

Viscosity

Permittivity

Use defined properties

## Interaction properties

List of interaction properties:

Interface tension

User defined properties

## Correlations

### Correlation search

The algorithm for calculating TPD and interaction properties is shown as follows.

For each T or P range (given in the literature), it consists of 3 steps:

Find the correlation with T & P within the first T or P-range. Calculate value according to the correlation function for this range.

Find the correlation with only T within the first T or P-range. Calculate value according to the correlation function for this range.

Find the nearest correlation, taking only T into account. Perform nearest neighbour extrapolation.

### Correlation functions

The correlation functions in Dyssol are listed below. The letters are constants. For different temperatur and pressure ranges, different functions should be applied.

Constant:

Linear:

Exponential:

Power function

Polynomial:

Shomate heat capacity:

Shomate standard enthalpy:

Shomate standard entropy:

List of T-values (user defined):

List of P-values (user defined):