The Gas analytical engine models steady, one-dimensional, isothermal flow for ideal and non-ideal, variable-density gases. Darcy Weisbach equations and the Ideal Gas law are used to describe pressure-temperature-density relationships. Non-Ideal Gas and Constant-Density Gas analyses are also available. Mass-flow calculation is used to determine velocity.
This module is steady-state, although users can create multiple scenarios (for instance, 24 different scenarios, each representing one hour, with different loads for each hour within a facility). The Gas analytical software allows analysis to be carried out using many different flow units (SCFM, MSCFD, lb/hr, etc.) and pressure units (psi, psf, inches of water, or atm: Users can choose whether these are relative to atmospheric or gauge pressure). The software also generates warnings of choking/sonic flow conditions.