Comprehensive decription of solids

Compared to the characterization of fluids the description of solid materials is far more complex. Properties of solid materials can be categorized according to the complexity of the data. For a complete description of solids three categories have to be treated:

Single-value properties like temperature, pressure or phase fraction consist of a name, a numeric value and a dimension.

Distributed properties for all kind of populations like a particle size distribution consist of a name, the definition of class intervals including dimension and numerical values describing the amount of matter within each class. Distributed properties may depend on each other.
Dependent single-value properties can obtain a different value for each class of a certain distributed property. They also consist of name and dimension.

The data structure of the material stream object is shown in the figure below. Within the stream an entry for each of the defined single-value properties (temperature, pressure) is required. The distributed properties of each phase are stored using a multi-dimensional matrix which allows for efficient storage of dependent distributed solids properties. The dimension of this matrix is equal to the number of defined distributed properties of a phase. With this approach multi-dimensional distributions can be defined without implying any hierarchy.

For dependent single-value properties a number of values has to be stored, one for each combination of class intervals the property depends on. When the property depends only on one distributed property, like the density of the stream in figure 2, the number of values stored equals the number of classes defined for the distributed property. For the density a value for each of the defined compounds is stored. In case of multiple dependences the number of values stored is equal to the product of the number of classes of the distributed properties the dependent single-value property is related to. As for the moisture defined the number of values equals the number of compounds times the number of particle size classes.