1. The University of Texas at Austin Spring 2013 CAEE Department Course: Modeling of Air and Pollutant Flows in Buildings Instructor: Dr. Atila Novoselac Office: ECJ, 5.422 Phone: (512) 475-8175 e-mail: atila@mail.utexas.edu http://www.ce.utexas.edu/prof/Novoselac Office Hours: Tuesday and Thursday 11:00 a.m.–12:00 p.m.

2. Discuss the Syllabus Describe scope of the course Introduce the course themes Answer your question Fluid dynamics review Today’s Lecture Objectives:

3. Introduce Yourself Name Background - academic program and status Professional interests Reason(s) for taking this course

4. Motivation for Modeling of Indoor Air Distribution using CFD: Major exposure to contaminant is in indoor environment Ventilation system provides contaminant dilution Controlled airflow (ventilation) can considerably improve the IAQ and reduce the ventilation air requirement Air-flow transports pollutants – gaseous and particulate Contaminant concentration in the space is more or less non-uniform – It affects: emission, filtration, reactions, exposure

5. Why to Care About Indoor Airflow Distribution ? Pollutant concentration is very often non-uniform - Exposure depends on dispersion Perfect mixing We can control exposure by controlling the flow field

6. Examples of Exposure Control by Ventilation Systems 1) Control Exhaust 2) Control Supply Supply diffusers

7. Heater (radiator) Example of Buoyancy Driven Flow: Airflow in a Stairwell

8. Example of Force Convection Contaminant Concentration in a Kitchen

9. Example Particle Dispersion

10. Fluid Dynamics Continuity: Momentum:

11. Numerical Methods

12. Simulation Software (CFD) Simulation Software If Garbage IN Then Garbage OUT Input Output

13. 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. Course Objectives

14. Topics: 1. Course Introduction and Background1 wk 2. Fundamentals of fluid dynamics 2 wks 3. Turbulence models1.5 wks 4. Numerical methods and parameters 2 wks 5. CFD modeling parameters 1.5 wks 6. Introduction to CFD software 1 wk 7. Application of CFD for building airflows 1 wk 8. Simulation of IAQ parameters 1 wk 9. Simulation of thermal comfort parameters 1 wk 10. Modeling of aerosols 1 wk 11. Air and pollutant flows in the vicinity of occupants 1 wk 12. Accuracy and validation of building airflow simulations 1 wk 30% 40%

15. Prerequisites - Fluid Dynamics Knowledge of the following is useful but not necessary: -HVAC systems -Numerical analysis -Programming

16. Textbook 1)An Introduction to Computational Fluid Dynamics, Versteeg, H.K. and Malalasekera, W. References: 2) Computational Fluid Dynamics –The Basics With Applications Anderson 3) Turbulence Modeling for CFD Wilcox

17. Handouts Copies of appropriate book sections An Introduction to Computational Fluid Dynamics I will mark important sections Disadvantage - different nomenclature I will point-out terms nomenclature and terminology differences Journal papers and CFD software manual Related to application of airflow simulation programs

18. Energy simulation software Airpark Fluent

19. There is a large availability of CFD software ! -Star CD We have it and you will use it - Phoenics -CFX -Flow Vent

20. Star CD Software – Air Quality in the Airplane Cabin

21. TENTATIVE COURSE SCHEDULE

22. Continues from previous page

23. Test 25% Homework Assignments 30% Midterm Project10% Final Project & Presentation30% Classroom Participation 5% 100% Grading

24. Participation 5% Based on my assessment of your participation in the class How to get participation points Come to class Submit all assignments/projects on time Participate in class discussions Come to see me in my office

25. Homework 30% (each 10%) Total 3 HW1 Problems related to fluid dynamic HW2 Problem related to turbulence modeling HW3 Problem related numeric

26. Midterm Exam 25% Out -class exam (90 minutes) At the the end of March -we will arrange the exact time Problems based on topics cover in the first two parts of the course

27. Midterm Project 10% Individual project Use of CFD program for air and pollutant flow analysis Primary goal is to get familiar with the CFD software

28. Final Project 30% Use of CFD for detail airflow, thermal and IAQ analyses Different projects topics –Real engineering an/or research problems Final presentation (10-15 minutes)

29. Previous Course projects -Human Exposure to toxins

30. Previous Course projects - Surface Boundary Layer

31. Previous Course Projects - Hydro-Jet Screen

32. Previous Course projects - Natural Ventilation

33. Design of ventilation system Smoke management Natural ventilation Human exposure to various pollutants Your suggestion More CFD Final Project:

34. Grading > 93 A 90-93 A- 86-90 B+ 83-86 B 80-83 B- < 80 C-, C, C+

35. Course Website All course information: http://www.ce.utexas.edu/prof/Novoselac/Classes/ARE372/ Except your grades and HW solutions Grades and progress on the Blackboard On the course website Look at Assignments sections Review class material ahead of time use posted class notes

36. My Issues Please try to use office hours for questions problems and other reasons for visit Tuesday and Thursday morning reserved - Class preparation Please don’t use e-mail to ask me questions which require long explanations Come to see me or call me Suggestions are welcome The more specific the better

37. Fluid Dynamics Review

38. Conservation equations

39. Important operations Vector and scalar operators: Total derivative for fluid particle which is moving: x z y vector scalar V any scalar

40. Continuity equation -conservation of mass Mass flow in and out of fluid element Change of density in volume = = Σ(Mass in) - Σ(Mass out) ………………. Volume V = δxδyδz Infinitely small volume Volume sides: Ax = δyδz Ay = δxδz Az = δxδy

41. Shear and Normal stress τ yx

42. Momentum equation –Newton’s second law Stress components in x direction total derivative forces per unit of volume in direction x ……………….. ……………… ……………. dimensions of fluid particle

43. Momentum equation Sum of all forces in x direction Internal source x direction y direction z direction

44. Newtonian fluids Viscous stress are proportional to the rate of deformation (e) Elongation: Shearing deformation: Viscous stress: 0 For incompressible flow viscosity

45. Momentum equations for Newtonian fluids x direction: y direction: z direction: After substitution: