PhD Thesis - staffweb - University of Greenwich

PhD Thesis by John Ewer.momentum components. Also variable usage is determined by simulation type. Using explicitlydeclared cell class attributes for cell properties (e.g. "cell.pressure", "cell.old_pressure","cell.last_pressure", and "cell.previous_pressure") would always use storage regardless of theactual requirements of simulation. It was decided that simple "data" arrays of properties shouldbe created and then indexed by parameter type identifiers (See Figure 3.7.7-2). The "slots", inthe data array, can then be assigned as required by the simulation. This was particularlyimportant, for example, in a simple heat-transfer simulation where the overhead of storing theother flow variables is highly undesirable. This approach also allowed for functional data accesswith expressive selection arguments, and ease of data monitoring. The argument against usingsuch a method revolves around the fact that it is then possible to confuse the indexing to theslots. In order to prevent inappropriate access to the slots, the indexing mechanisms were madeprivate to the class and embedded within data access functions.Array of cell objectsdataPRESSURENEWESTCELLLASTOLDnum_of_facesArray of point objectsmaterialvolumeindex linkPOINTArray of face objectsdataxyindex linkFACEzSKIN_FRICTIONareanum_of_pointsFIGURE 3.7.7-2 : Re-engineered Object Oriented data structures in C++.3-63