1. Lecture Objectives Discuss specific class of problems
Discuss the CFD software

2. Challenging Problem: Application of CFD in a large space
EXAMPLE:
Five-Story Parking Garage Ventilation
Multi-space building
Course grid model properties
- The geometry should present correct geometry around large openings
- The ratio between the total flow area and the floor area should be the same as in full scale
- Air supply and return openings should be defined in a coarse grid sufficient for momentum and energy flow predictions
The result will define global air and energy flow between zones but accuracy is insufficient for an analysis of the detail air velocity distribution in the zones.

4. Natural Ventilation: Science Park, Gelsenkirchen, Germany

5. Detail air velocity distribution in room
Detail description
of geometry
Simple Description of Interior
Furnishings can be described as
A volume with additional pres-
sure drop in the momentum
Equations:

6. Engineering Application
Unlimited number of problems!
For example:

7. Human Exposure Airflow in the room vs. Airflow in vicinity of occupant
CO2 distribution
- Course mesh
- Simple geometry
CO2
sources
Occupied zone

8. Simulation of an occupant
Detailed geometry:
Good for local convection coefficient calculation at the skin
Effect of breathing an movement decrease accuracy

9. Different level of geometry details
Avaraged geometry can be used for global effects
Simple geometry can be used for semi-global effects
Detailed geometry should be used for local effects
Conclusions from geometry analysis (Peter Nielsen)
Semi-global effect
Differences in geometry have a small influence on
velocity, temperature distribution, contaminant distribution
far from the manikin
Local effect
Differences in geometry have an effect on velocity and
concentration distribution close to a person and exposure of
a person

10. We Often Need Experimental Validation
Room with nonuniform temporal
and spatial distribution of particles
(for example smoke)
Validation results for 0.74 m S1
CFD model
Monitoring
Position S1
Monitoring
Position S2 S2
Pollution Source
active 2 minutes
Experiment

11. Examples of CFD application in Indoor environment research
Some hot topics
Particle Transport in a boundary layer
Surface Chemistry
Air and particle flow in lung
Various analyses of fluid flow in building components and HVAC systems