Rocket Motor Data Reduction with MATLAB_3_

Fundamentals of Engineering for Honors – ENG H192 Lab 4: Aerodynamics Fundamentals of Engineering for Honors – ENG H192 Airfoil Terminology Fundamentals of Engineering for Honors – ENG H192 Angle of Attack Fundamentals of Engineering for Honors – ENG H192 Lift and Drag • Lift is defined as a force normal to the relative wind • Drag is a force parallel to the relative wind Fundamentals of Engineering for Honors – ENG H192 How is Lift Produced ? • Air moving over the top of the wing has a higher velocity than the air on the bottom High Velocity = Low Pressure Low Velocity = High Pressure The resulting pressure difference causes a force that pushes up on the wing (aka lift) • • • Fundamentals of Engineering for Honors – ENG H192 How Angle of Attack and Camber Affect Lift Fundamentals of Engineering for Honors – ENG H192 What About a Symmetric (no camber) Airfoil ? Fundamentals of Engineering for Honors – ENG H192 Bottom Line: Cambered Vs Symmetric • Cambered airfoils produced lift at zero angle of attack. • Symmetric (no camber) airfoils do not produce lift at zero angle of attack Fundamentals of Engineering for Honors – ENG H192 What Happens to an Airfoil when it Stalls ? • Flow over the top surface separates from the airfoil, resulting in a high pressure wake region Fundamentals of Engineering for Honors – ENG H192 Sources of Additional Airfoil Information • How Airplanes work: http://www.howstuffworks.com/airplane4.htm • NASA’s FoilSim II airfoil simulation program: http://www.grc.nasa.gov/WWW/K12/airplane/foil2.html • Airfoil Database (Hint: look at low Reynolds number airfoils for the upcoming lab) : http://www.aae.uiuc.edu/mselig/ads/coord_database.html