Simular Air: a three dimensional transient air flow program

SIMULAR AIR is a computer code for calculating the three dimensional transient indoor air flow using a k,e-turbulence model. It solves the nonlinear partial differential equations for momentum, energy, continuity, turbulence and air purity by an implicit time marching technique. The equations are modeled by a finite volume procedure. The model handles a variety of flow, temperature and heat flux boundary conditions including prescribed inflows and outflows. All boundary conditions can be defined time dependent. The computer code is able to handle obstacles in the flow region to simulate furniture. The results are presented graphically on the screen or as numerical output on a printer or a file. SIMULAR AIR is available for workstations but can also be run on a standard PC with an 80386 processor and either an Intel 80387 or a Weitek coprocessor under an extended DOS operating system. All modules of the program (preprocessing, calculation and graphical output) are menue driven and provide online help. The program has been used to calculate air movement, distribution of temperature and fraction of fresh air in a three dimensional model room with alternating air supply and exhaust. Results of two calculations on a PC with respectively alternating and static air supply show only minor differences. They agree well with experimental investigations of the same room in both cases. The only influence of the alternating ventilation shows up to be a faster reaching the final distribution.