New Mass Transport Elements and Components for the NIST IAQ Model.
New Mass Transport Elements and Components for the NIST
IAQ Model.
(5936 K)
Axley, J. W.
NIST GCR 95-676; 33 p. July 1995.
Sponsor:
National Institute of Standards and Technology,
Gaithersburg, MD
Available from:
National Technical Information Service
Order number: PB95-255899
Keywords:
contaminant dispersal; filtration; indoor air quality;
mass transport; modeling; ventilation
Abstract:
This report presents new mass transport elements for the
next generation of the NIST IAQ Model that may be used
to model [a] homogeneous (bulk-air) chemistry within
well-mixed chamber, [b] aerosol mass transport within
well-mixed chambers and fractional particle filtration
in building filtration devices, and [c] heterogeneous
(surface-related) physical processes and chemical
transformations including those governing the behavior
of gas-phase air cleaning devices. In an effort to
maintain rigor, generality, and flexibility, each
transport process is formulated in terms of the
elemental mass transport steps that together govern the
overall process. In this way, the more complex
processes may be represented as component equations that
are assembled from fundamental element equations. The
element/component assembly method, upon which the NIST
IAQ Model is based, provides a general and modular
approach to the formulation of systems of equation
governing the mass and air transport in buildings to
effect indoor air quality analysis. In this approach,
the solution of the system equations is a
computationally distinct task that may be achieved using
a variety of numerical methods. The third chapter of
this report discusses numerical and computational
strategies for the solution of the system equations that
are compatible with both the existing and proposed new
mass transport elements and presents candidate
strategies that appear to be most promising. Finally
the fourth chapter of this report considers user
interface strategies to implement the proposed new mass
transport elements and components.
Building and Fire Research Laboratory
National Institute of Standards and Technology
Gaithersburg, MD 20899