The role of computational fluid dynamics (CFD) has become important in analyzing fluid flow, heat transfer, and species transport. This is particularly evident in problems dealing with interior building flows, air quality, and ventilation design. In many instances, it is quite difficult or impossible to obtain reliable experimental measurements of flows. Providing one can properly identify boundary conditions for the problem geometry, realistic and accurate estimates of the flow rates, velocity profiles, and pressure drops can be obtained using numerical methods. In addition, the effects of buoyancy on air currents associated with free or forced ventilation within building configurations can also be simulated.

There are many commercial CFD software packages available, with varying degrees of sophistication and expense. Such packages allow one to effectively assess flows within practically any geometry or HVAC configuration. When experimental data are available, CFD augments the results and aids in the interpretation of the data. With the increasing power and decreasing costs of computers, sophisticated fluid flow modeling has become a normal part of the design and evaluation process of HVAC systems. The faculty and staff in CMEST have the ability to perform these calculations for a wide variety of building applications using both in-house and commercial software packages.

Finite element methods are being used to investigate the dynamic characteristics of partial and complete structural systems associated with air distribution and ventilation systems. For example finite element models can be used to investigate the resonant vibration modes of a propeller fan impeller and to predict the rotational speeds that correspond to the resonant modes. The model can then be expanded to examine the dynamic or vibration behavior of the total system, consisting of fan impeller, motor, and motor mount. The faculty and staff of CMEST have access to PC-based finite element codes, such as COSMOS, CASA/GIFTS, Algor, and SAP83, and to mainframe codes like SAP IV, NONSAP, and FIDAP, which can be run on the Cray supercomputer.

In-house computer programs have been developed which can be used to conduct complete acoustic analyses of air distribution and ventilation systems. These programs can be used to examine the many paths that sound can travel from sound sources within air distribution and ventilation systems to occupied areas within the buildings these systems support.