1. Clarkson
UNIVERSITY
defy convention
Simulation of Particle Motion for a Model of Indoor Air Ventilation System
Department of Chemical Engineering, Department of Mechanical & Aeronautical Engineering
CARES
Xinli Jia, John B. McLaughlin, and Goodarz Ahmadi
ABSTRACT
Simulation results for airflow conditions in a room with displacement ventilation are presented. Sample pollutant particle trajectories are also studied and the effect of various forces are discussed.
EFFECT OF GRAVITY ON PARTICLE FATE
EFFECT OF PARTICLE INERTIA AND GRAVITY ON PARTICLE FATE
DISPLACEMENT VENTILATION
Gravity has little effect on a 2 micron particle (trajectories on right), but it causes a 13.4 micron particle (trajectories on left) to deposit on one of the objects. (The scales are in terms of grid spacings.)
A 2 micron particle enters the exhaust, but a 4 micron particle is centrifuged from the vortex and deposits on the ceiling. The larger particles (8 and 13.4 microns) sediment out.
SMALL SCALE MODEL OF A ROOM
Small-scale, two-dimensional model
Geometric parameter values: inlet velocity=7.5 cm/s. inlet width=2 cm, room size=40cm x 16.6 cm, object heights=5cm, 4cm, and 3cm.
Forces included: Stokes drag, gravity
Particle diameters: 2 microns-6.7microns
Density ratio=1000
SIMULATION OF 70NM NANOPARTICLES RELEASED FROM A CONTINUOUS SOURCE IN A CHANNEL.
A flexible simulation tool was developed with a Java-based user interface for problems involving particle motion in laminar and turbulent flow.
This module illustrates the dispersion of nanoparticles in a channel flow. Brownian motion causes the trajectories of particles emanating from the same source to deviate.
NANOPARTICLE MOTION
IN A CHANNEL
Brownian motion and the lift force are
not included in the above example. They
were included in the example on the right.
The lift force can re-suspend particles.