The discussion was essentially about how to better describe what is a given property. The Process Modelling Environment, through its Material Object, will store properties of any Compound and especially of pseudo-Compounds. The values stored will be made available to any Unit Operation model having a need for these values and that could set them in a Material Object once the calculation of the Unit Operation is completed.
A property is usually defined through its name. It appears necessary to develop some metadata on properties in order to facilitate the communication between a PME and a Unit Operation. For example seems easier for the communication if the Unit Operation has a more accurate knowledge of how the Material Object is able to convert a property from one basis to another. Considering the nature of Petroleum Properties (and often the difficulty to convert a property from one basis to another), it appears also that a PME may have a preference for a basis in which a given property is stored.
This analysis leads to a proposal to add two methods to the ICapeThermoPetroFractions interface: GetPropertyInfo and GetPropertyDimensionality. The Unit Operation would exercise these two methods for one property at a time (the property being mentioned through its name, a string). The Unit Operation model would have already retrieved the list of properties from the Material Object.
GetPropertyInfo would give access to different pieces of information, each a single value. It is a design decision related to the on-going COBIA project not to mix single value returned with array returned through the same method. Hence GetPropertyInfo would give access to the native basis in which the property is stored by the PME (NativeBasis attribute), to the property definition (a string describing how the property is referenced, typically through a standardized measurement method), to a Boolean telling if mass basis is supported (MassBasisSupported attribute), to a Boolean telling if molar basis is supported (MolarBasisSupported attribute), to a Boolean telling if volume basis is supported (VolumeBasissupported attribute), to a Boolean stating if the property can be used as a compound property (IsCompoundProperty attribute), to a Boolean stating if the property can be used as a bulk property (IsBulProperty attribute). A given property can be simultaneously a compound property and a bulk property. Should be at least one of the two possibilities.
GetPropertyDimensionality would return an array describing the dimensions in which a given property is measured and valued. The same array of dimensions defined for a Parameter would be used, for the sake of consistency.
Bryan Research & Engineering has provided the group with an updated table of properties and their measurement methods and so on. Some formatting needs to be performed in order to simplify the layout of that table which ought to be integrated in the interface specification document.
Comments are welcome.Statistics: Posted by colancto — 27 June 2017, 16:26
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