AE/ME 8xxx Wind Engineering

1. AE/ME 8xxxWind Engineering Lecture #1 Lakshmi N. Sankar lsankar@ae.gatech.edu

2. OVERVIEW • About the instructor • Overview of the Course • Content • Deliverables, exams, quizzes • Grading Policy • Access to instructor • Resources

3. About the Instructor • Lakshmi Sankar • Regents Professor and Associate Chair • Room 360 • School of Aerospace Engineering • Atlanta, GA 30332-0150 • Phone: 404-894-3014 • lsankar@ae.gatech.edu • www.ae.gatech.edu/~lsankar/

4. About the instructor (Continued) • Courses taught include • Introduction to AE (AE 1350) • Low Speed Aerodynamics (AE 2020) • High Speed Aerodynamics (AE 3021) • Airfoil and Wing Design (AE 3021) • Helicopter Aerodynamics (AE 6070) • Wind Engineering (This course) • Computational Fluid Dynamics • Master’s Thesis (AE 7000) • Master’s Special Problem (AE 8900) • Ph D Thesis (AE 9000)

5. About the instructor (Continued) • Research areas include • Helicopter aeromechanics • Wind turbine modeling and design • Aerodynamics of Turbomachinery • Aircraft Aerodynamics • Please see my web site for a list of publications, and Ph D students graduated in recent years.

6. Overview of this Course • The course material will be posted on t-square. • Look under the resource section for lectures • Look under assignments for homework/ exam/ papers and their deadlines • Look for your grades • Look for your classmates’ work at the end of the term.

7. Overview of the Course (Continued) • All assignments will be open book and notes • You will submit your work electronically at the t-square web site. • You will have several weeks of advance notice. • If you need an extension, please contact me early. • Write as you go, document your work as you go. • You are always welcome to contact me with questions. • E-mail is preferred!! • Telephone calls to 404-894-3014 are always welcome.

8. Overview of the Syllabus • First few lectures will focus on • Overview of Wind Engineering (6 hours in normal chalk board lecture mode; actual time will vary depending on the mode of delivery from 3 hours to 5 hours) • Benefits of wind energy • Assessment of Wind Resources • Assessment of means of energy production, consumption, and cost • Green credit • Wind turbine terminology and definitions • First assignment will be posted after these lectures. • You will select a wind turbine site and learn all about that site. • We will show examples of what information to collect from work of your peers.

9. Overview of the Syllabus (Continued) • Actuator disk model of horizontal axis wind turbines (3 hours) • Earliest work of wind turbines modeled wind turbine as a disk across which mass is conserved, momentum is lost, and energy is lost. • This theory may be learned from very simple 1-D approach dealing with the conservation of mass, moment, and energy. • See www.ae.gatech.edu/~lsankar/AE2020 if you are not familiar with these concepts. • We will point to these resources as we go!

10. Overview of the Syllabus (Continued) • Review of airfoil aerodynamics (9 hours) • Lift, drag, and pitching moment • Panel method for airfoil analysis • Modeling laminar and turbulent boundary layers, and transition • Airfoil design for wind energy applications • This material is intended for non-AE students who may not be familiar with these concepts. • Aerospace engineers will benefit as well from a brush-up of these basic concepts. • We will talk about public domain and NASA/DoD computer software for modeling airfoil aerodynamics as well. • Any engineer planning to work in the wind turbine industry should master one or more of these tools and add it to the toolkit.

11. Overview of the Syllabus (Continued) • Blade element theory (9 hours) • Inflow models based on combined blade element theory • Incorporation of swirl losses in inflow • Root and tip loses, and stall delay models • Assessment of publicly available wind turbine modeling tools • This method is similar to helicopter and fixed wing aerodynamics, but there are subtle differences. • We will cover these concepts from the very basic aerodynamic principles discussed earlier. • You will learn to model wind turbines using public domain solvers. • You may write your own in Matlab, Excel, or C or Fortran

12. Second Assignment • Your second assignment will involve learning (or writing) your own wind turbine analysis tool. • You will validate this tool by comparing the predictions of this tool to wind tunnel and field data. • How does the power production from a wind turbine of a given configuration vary with wind speed? • This would be your second deliverable.

13. Overview of the Syllabus (Continued) • Horizontal axis wind turbine design using blade element theory (6 lectures) • A wind turbine is classified by • Number of blades • Planform (how does chord vary with radial location?) • Twist distribution (how does the angle the chord makes with the plane of rotation) vary with radial location? • Airfoil aerodynamic properties (How does lift, drag, pitching moments vary with the angle the airfoil makes with oncoming airstream?) • Blade RPM • Tower height (where is the axis of rotation placed relative to the ground?) • Root cutout • We will learn about how to design your own wind turbine using the tools validated in assignment #2. • This would be your third deliverable.

14. Overview of the Syllabus (Continued) • Conversion of mechanical energy into electricity (3 hours) • Basic AC Power Generators • Hybrid Power Systems • Hybrid System Modeling and Simulation • We will discuss the issues that arise when plugging a wind turbine (or a farm of wind turbines) to the grid. • We will talk about combining wind turbines with other energy sources (diesel, gas turbines, nuclear, dry cell batteries, fuel cells, etc) • We will discuss the characteristics that need to be modeled.

15. Overview of the Syllabus (Continued) • Economic analysis of wind turbine systems (3 hours)     • We will point to public domain software that you may wish to use to conduct an economic analysis. • You will be raising capital from share holders who expect a return on investment • You will be borrowing the rest from a bank which charges you interest • You will be selling the power to a local utility at fair market prices (cents per Kilo Watt-Hr) • You may get green credit or carbon-offset credit • You will make a case for wind energy at the site you chose way back in Assignment #1. • You may end up with the conclusion that the economic conditions do not favor wind energy sites at this time, but in the future. • The fourth deliverable is this economic analysis.

16. Overview of the Syllabus (Continued) • Impact of wind turbines on the environment (3 hours) • Wind turbines help the environment • They may harm birdlife, disturb reservations or protected land, and affect commercial and residential property values • We will review how these issues are analyzed and factored into the design and construction of a wind turbine site or wind farm.

17. Overview of the Syllabus (Continued) • Presentations by students (3 hours) • You will submit a final report and a PowerPoint presentation that is shared with the entire class. • For distance learning students, critique of your work and constructive feedback is optional. • The instructor may use your findings and artwork in future semesters. • Do not include copyrighted or proprietary results • Cite publicly available resources, get permission if it is a private communication.

18. In summary.. • This course introduces to horizontal axis wind turbines • How they operate? • How are they modeled and analyzed? • How are they designed? • How is the economic analysis done? • What are the environmental impacts that a designer should be concerned about? • I look forward to working with you throughout the semester. • I am always just an e-mail or phone call away!