1. Next Class Final Project and Presentation – Prepare and email me the ppt files 5-7 slides Introduce your problem (1-2 slides) – Problem – Why CFD? Methods (2 slides) – Description of the model – Tests, sensitivity analyses, … Preliminary results (2 – 3 slides) – 5 minutes presentation +2 minutes for questions – Schedule: Alphabetical – Direction for the final report at: http://www.ce.utexas.edu/prof/Novoselac/classes/ARE372/Projects_ol/Project2.doc http://www.ce.utexas.edu/prof/Novoselac/classes/ARE372/Projects_ol/Project2.doc

2. Lecture Objectives -Learn about Star-CCM+ and ANSYS-Fluent -Presenter Shichao Liu -Meshing -UDF -…. -Talk about parallel computing -Review course topics

3. CFD software Commercial: -Fluent (Airpak) www.fluent.com/ www.fluent.com/ -Star CD www.cd-adapco.com/ www.cd-adapco.com/ -Phoenics www.cham.co.uk/ www.cham.co.uk/ -Ansys CFX http://www-waterloo.ansys.com/ http://www-waterloo.ansys.com/ -Flomerics (Flowvent) www.flomerics.com/ www.flomerics.com/ -and many other Some free research: -NIST Smokeview www.fire.nist.gov/fds/download/ www.fire.nist.gov/fds/download/ -ASHRAE - zero equation (published only source code)

4. Big linear systems your project full-blown 3D problem! – More than 1 million nodes. Memory becomes a problem – cannot store a matrix on one processor. Slow calculation! – solution : use many processors! Parallel methods BIG matrix p3p3 p2p2 p1p1 p4p4 Split matrix to 4 processors in this example!

5. Course Masterial Review Navier-Stokes equations and RANS Turbulence modeling Discretization and equation solver Boundary conditions Numerical properties Specific CFD problems

6. Conservation Equations Navier Stokes Equations

7. Reynolds Averaged Navier Stokes equations Similar is for S Ty and S Tx Momentum: Continuity: 4 equations 5 unknowns → We need to model 1) 2) 3) 4)

8. Modeling of Turbulent Viscosity Fluid property – often called laminar viscosity Flow property – turbulent viscosity MVM: Mean velocity models TKEM: Turbulent kinetic energy equation models LES: Large Eddy simulation models RSM: Reynolds stress models Additional models:

9. Discretization and equation solver Step1: solve V* from momentum equations Step2: introduce correction P’ and express V = V* + f(P’) Step3: substitute V into continuity equation solve P’ and then V Step4: Solve T, k, e equations Guess p* end Converged (residual check) yes no p=p* Discretization of RANS SIMPLE algorithm

10. 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. Summary of Course Objectives