Conversion of DAP models to SPEEDUP

Several processes at the Savannah River Site are modeled using Bechtel's Dynamic Analysis Program (DAP) which uses a sequential modular modeling architecture. The feasibility of conversion of DAP models to SPEEDUP was examined because of the benefits associated with this de facto industry standard. The equation-based approach used in SPEEDUP gives accuracy, stability, and ease of maintenance. The DAP licenses on our site are for single-user PS/2 machines whereas the SPEEDUP product is licensed on a VAX minicomputer which provides faster execution and ease of integration with existing visualization tools. In this paper the basic unit operations of a DAP model that simulates a ventilation system are described. The basic operations were modeled with both DAP and SPEEDUP, and the two models yield results that are in close agreement. Since the basic unit operations of the DAP model have been successfully duplicated using SPEEDUP, it is feasible to proceed with model conversion. DAP subroutines and functions that involve only algebraic manipulation may be inserted directly into the SPEEDUP model or their underlying equations may be extracted and written as SPEEDUP model equations. A problem modeled in SPEEDUP running on a VAX 8810 runs approximately fifteen times faster in elapsed time than the same problem modeled with DAP on a 33 MHz Intel 80486 processor