Building DOP Microsolvers from GAS_SubSolver

Introduction

One of the most common types of solvers are the microsolvers associated with fluid simulations. Each microsolver is designed to perform one stage of a fluid simulation.

These solvers do not have to be limited to fluid dynamics, however, as the general idea can be applied to any separable dynamic system.

While any SIM_Data that derives from SIM_Solver can be part of a solve chain for a DOP Object, the GAS_SubSolver provides a useful collection of methods useful for writing solvers that operate on one object at a time and manipulate the field and geometry of an object.

Subclassing

When deriving from GAS_SubSolver several steps must be performed.

• Override GAS_SubSolver::solveGasSubclass. This is the function that does the actual work. Note this is different from SIM_Solver::solveObjectsSubclass in that you are only given a single object. Also, before this is invoked, any subdata of type SIM_Solver will be solved. This ensures any data wired into this data will be solved prior to this solver, ensuring the top-down, left-right solve order the network graph implies.
• Define GET_DATA_FUNC_S style macros for the parameters you wish to support. The GAS_SubSolver has already mixed in SIM_OptionsUser so is ready to turn into an DOP_Auto.
• Write a static function to create the SIM_DopDescription that will be used by the auto node. The token names in the the PRM_Name of the PRM_Template returned must match the tokens in the GET_DATA_FUNC_S macros.
• Create the macros to invoke the boiler plate for SIM_Data, namely DECLARE_STANDARD_GETCASTTOTYPE and DECLARE_DATAFACTORY.

Gas SubSolver Examples

An example of a simple gas sub solver that adds two fields together can be seen with SIM/SIM_GasAdd.C and SIM/SIM_GasAdd.h.