1. Lecture Objectives Discuss HW4 Multizone modeling
Convergence issues
Learn about “false time step” relaxation
Multizone modeling
Review class material

2. Multizone modeling

3. Example

4. Multizone modeling CONTAM and COMIS
NO momentum equation
Just pressure, temperature, and continuity
Depends heavily on boundary condition and orifice coefficients that define flow between zones
Good for buoyancy driven flow

5. Boundary condition for multizone modeling
Exterior pressure (wind)
Temperature distribution
(requires some assumption or energy modeling)

6. Wind pressure around building
Very complex and unsteady
For multizone we are introducing many simplifications: ….

7. Multizone vs. Moltizonla
“Multizonal” is like CFD (detailed grid with no orifice between i- between zones) but no momentum equation

8. CFD software Commercial: Fluent (Airpak) www.fluent.com/
Star CD
Ansys CFX
Phoenics
Flomerics (Flowvent)
and many other
Some free research:
OpenFOAM
NIST FDS and Smokeview
ASHRAE - zero equation (published only source code)
Many more

9. Summary of Course Objectives
Recognize the physics behind various numerical tools used for solving airflow problems.
Employ basic numerical methods for solving Navier-Stokes Equations.
Apply CFD for airflow simulations in buildings and use these tools in design and research.
Evaluate the thermal comfort and indoor air quality (IAQ) with different ventilation systems.
Assess human exposure to different pollutant types.
Critically analyze and evaluate CFD results.
First is overall theme – relevant to everyone
2nd also relevant to everyone
example of mechanical engineer resisting your change
Project manager- knowledge of planning for BES stages
4 main areas – HVAC, electrical, lighting, plumbing
Noise control and acoustics – if we have time