Task 2B Measurement of Transport in the PME D.R. Marr, I. Spitzer, S. Kaligo M.N. Glauser, H. Higuchi July 26, 2006

Motivation for this Task Human exposure to indoor air contaminants emitted by the person (e.g., pathogens, body odors), or as a result of the person’s activities (e.g., personal dust cloud) require higher-resolution measurements in the personal microenvironment (PME). Steady and unsteady velocity, turbulence characteristics, temperature, and contaminant concentrations (gaseous & PM). Effects of breathing, coughing, body motion. Especially needed for ventilation schemes that produce steep gradients (e.g., personal ventilation systems). Such measurements are used to explore the underlying physics of contaminant transport and to calibrate computational tools. High-resolution measurements require the use of temporal and spatial resolution measurement techniques (e.g., PIV, PDPA…)

Differentiation of this Work from other Efforts Several investigators, notably Kato et al. and Nielsen et al. have undertaken detailed measurements of the flow in the PME, and offered such measurements as a benchmark database. While these measurements provide valuable insight into the mean flow and the turbulence intensity, they do not provide sufficient resolution of the turbulence structure: No characterization of the multiple length scales* No characterization of the anisotropy of the turbulent fluctuations No account of the unsteady motion of the person This effort is aimed at addressing these “deficiencies” through: Detailed measurement of turbulent fluctuations and the application of analytical techniques to extract moment characteristics Study of the effect of unsteady motion on the PME (air and PM) *Wolfshtein, M., Naot, D., and Lin, A.: Models of turbulences, Ben-Gurion University of Negev, Report ME-746, Israel, 1974. *Cole,D., Glauser,M.,1998.“Flying hot-wire measurements in an axisymmetric sudden expansion”. Experimental Thermal and Fluid Science,18,pp.150–167. *Kantha, L.H., 2004. The length scale equation in turbulence models. Nonlinear Process. Geophys. 11: 83–97.

Why a High-Quality Database is Necessary High-resolution data is needed to validate increasingly more detailed simulations of the PME and its interactions with ventilation flows. Low temporal/spatial-resolution databases cannot be employed to validate computer simulations focused on small scale details (e.g., DNS) in these complex, transitional flows. Validating such simulations with a database of scalar quantities acquired at low frequencies is a poor substitute when considering turbulent structure/time scales. Example: Validating code using a scalar velocity database can give incorrect boundary/initial conditions which will have a significant impact on simulation results. High-resolution experimental data must be employed for validating high-resolution computer simulations.

The Testbed: The Indoor Flowfield Laboratory (IFL) Experimental research including Breathing Thermal Manikin Time Resolved PIV Stereo PIV Multiple Traverse Systems PDPA

Coordination of Experimental and CFD Efforts The Symbiotic Relationship between experimental and CFD efforts CFD is used for guiding the design of the experiment. Parametric CFD simulations are employed to highlight the areas needing detailed experimental validation The experiments provide the high quality data for model development and validation

Example of Experimental Design Topic Information concerning plume rise allowed a proper determination for the ceiling height of the simulated cubicle.

Example of Experimental Design Topic (contd.) Interaction of the Plume with the Room

Example of Experimental Design Topic (contd.)

Validation Data for CFD Experimental results for code validation Initial conditions to get started

Averaged breathing waveform Standing Manikin PIV Averaged breathing waveform Setup

The phase averaged breathing waveform Max. flow rate 1 L/sec. Max velocity at peak 0.2 m/s

Standing Manikin PIV

Standing Manikin PIV

Standing Manikin PIV

Current Setup 6x8x8 ft. room simulating the average cubicle Seated, rotating, heated manikin utilizing average breathing waveform

Current Setup

Thanks to: US EPA NYSTAR (NY State Office of Science, Technology and Academic Research) Syracuse University Although the research described in this presentation has been funded wholly or in part by the United States Environmental Protection Agency through cooperative agreement CR 83199201-0, NY STAR Center for Env. Quality Systems/EPA Indoor Environmental Research Program, it has not been subjected to the Agency's required peer and policy review and therefore does not necessarily reflect the views of the Agency and no official endorsement should be inferred.