Validation of a computational fluid dynamics model developed for a homeless shelter.
Hudnall-J; Martin-S Jr.; Duling-M; Lawrence-R; Calvert-C; Coffey-C; Gandhi-V
American Industrial Hygiene Conference and Exposition, May 21-26, 2005, Anaheim, California. Fairfax, VA: American Industrial Hygiene Association, 2005 May; :71
Tracer gas measurements were compared to the results of a computational fluid dynamics (CFD) model developed for a homeless shelter. Sulfur hexafluoride (SF6) tracer gas was released in the first floor air handling unit (AHU). Sampling occurred in two main areas, the Respite dormitory area and the Common room used for meetings and gatherings. The Respite area was divided into eight sampling sites, evenly located throughout the space. The Common room was divided into four sampling sites. Sampling started 30 minutes after dosing and continued at regular intervals for two hours. All sampling was done during the day while the shelter had the lowest occupancy, but many clients remained in the building during testing. Due to the shelter's mission client activity could not be controlled during testing, such as entering/exiting the building and opening doors between rooms. The AHU operated normally and continuously during tracer gas testing. A detailed set of physical measurements, including ventilation flow rates, were taken for use in developing the CFD model. Using these measurements, the model was identical to the actual space, except that furnishings were not included. A linear relationship between the CFD model and the actual tracer gas concentrations was found (r2=0.99 in the Respite area and r2=0.96 in the Common area), however the decay rates from the model were different from tracer gas. This was expected as no information was put into the model regarding doors opening/closing, client movement inside the building, and leakage around windows, doors and through cracks in the building envelope. Since no ductwork was included in the model, duct losses were not considered. This relationship provides validation that CFD modeling can confidently be used to analyze air flow patterns on the first floor of the shelter.
Fluid-mechanics; Computer-models; Trace-analysis; Gases; Sampling; Models; Air-flow; Ventilation-systems
Research Tools and Approaches: Control Technology and Personal Protective Equipment
American Industrial Hygiene Conference and Exposition, May 21-26, 2005, Anaheim, California