* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Download Aerospace Engineering
Survey
Document related concepts
Transcript
Pre-Class Friday 10-5-12 What do you think Aerospace Engineers do? Pre-Class Monday 10-8-12 During a recent inter-school athletics event, four girls competed in the 10 km race. Jane Brown beat Lucy. Miss Guest beat Lynne. Anne was not third. Miss Joseph was not last. Miss Scott, who was not Anne, came just after Jane. Can you tell which girl came where? 1. Anne Guest 2. Lynne Joseph 3. Jane Brown 4. Lucy Scott Aerospace Engineering Improving life on Earth by changing how we fly above it Aerospace Engineers Design, develop, test, and help manufacture aircraft, missiles, rockets, and spacecraft Develop new technologies for military or commercial use Supervise the manufacturing of products Starting salary in 2010: $58,080; with average salary in 2006: $87,610 Divided into two basic fields – Aeronautical: aircraft – Astronautical: spacecraft Aeronautical Develop technology for use in aviation, defense systems, and attack projectile weaponry Specialize in structural design, guidance, navigation and control systems, and instrumentation and communication, as it applies to both civilian (commercial) and military products Other areas of knowledge are: aerodynamics, thermodynamics, celestial mechanics, propulsion, and acoustics Paper Winglets Objective – To test the design of a paper airplane with and without winglets. Materials – Student sheets – Rulers ― Copy paper ― Cardstock Procedures – Read the Background Information. – Follow the Procedures on student sheets. – Write on the ”tabled” page only. Pre-Class Tuesday 10-9-12 Which of the four black shapes is identical to the red one? The 4 Basic Forces of Flight Lift Thrust Gravity Drag When an aircraft is flying level at a constant speed, all four of these forces are in balance or equilibrium. Since air density and the acceleration of gravity changes with the height above the planet’s surface, all of these forces are affected by one thing: altitude. At higher altitudes, the air is thinner, while at lower altitudes the air is thicker. This change in the properties of air will affect how well the engine and wings work. The pilot only has the ability to directly affect three of these forces. The Forces of Flight Lift is achieved through the crosssectional shape of the wing (airfoil). As the wing moves through the air, – the wing's shape causes the air moving over the wing to travel faster than the air moving under the wing – the slower airflow beneath the wing generates more pressure, while the faster airflow above generates less (Bernoulli’s Principle) – this difference in pressure results in lift Lift will vary dynamically depending on the speed an aircraft is traveling at. Another factor to lift: Angle of Attack (AoA) – The angle at which the airfoil meets the airflow – The angle of the wing relative to airflow Lift Go Fly A Brick Objective – Simulate the landing of the Space Shuttle Materials – Shoebox – Cardstock (2) – Scissors – Tape Procedures – Follow the instructions on the lab paper – Be sure to answer the questions – Do not damage the shoebox! – Finish by the end of class Fill-in the Chart Pre-Class Wednesday 10-10-12 There are _____ forces of flight. Drag The force on an aircraft, as it is propelled through the air, that resists its motion due to the air flowing over the aircraft (causing friction) Can be increased or decreased depending on the size, shape, and cargo of the aircraft The maximum speed that can be obtained by a falling object The force of gravity is equally balanced by the air resistance force (drag) Constant speed, no acceleration Thrust The force generated by the air in front of the aircraft being pulled by the propeller or turbine of the engine and pushed back towards the tail Gives the aircraft forward velocity, which creates lift on the wings In general, the greater the thrust, the greater the airspeed Controlled by the throttle, which raises or lowers the revolutions-per-minute (rpm) of the engine Air Power Follow the instructions on the paper. Use a meter stick rather than a ruler. One balloon and one straw per group Replace question #3 with: “Find the maximum velocity of your air engine (balloon).” Pre-Class Thursday 10-11-12 If a plane is attempting to fly through a thinner atmosphere, what happens to the lift? Effects from Thrust and Drag Doppler Effect – The change in frequency of a wave due to the motion of the source or receiver – http://www.kettering.edu/~drussell/Demos/doppler/doppler.html Sonic Boom – Damaging to anything in its path – Could be cool to watch: http://www.youtube.com/watch?v=wHrwgRsX0BI – http://www.youtube.com/watch?v=GsKwrN0AimE ACCELERATION BY GRAVITY The Earth constantly accelerates all objects towards its center We use the variable g for the acceleration of gravity g = 9.8 m/s2 a = - g = - 9.8 m/s2 WEIGHT • Recall: a force is a push or pull on an object • The force of gravity, a.k.a. weight, is the attraction of any object (with mass) towards the center of the Earth W=m g W : weight in Newtons (N) or pounds (lb) m : mass in kilograms (kg) or slugs g : acceleration of gravity (9.8 m/s2 or 32 ft/s2) FALLING LAB Materials: – 6 pennies – stop watch – meter stick – tape Objective: – Determine the acceleration of gravity Each group will turn a paper into me today. PROCEDURES Stack five pennies and tape them together. Drop the five pennies 3 different times. Measure the distance fallen and the time it took to fall to the ground. Determine the acceleration of gravity. Repeat the experiment for the single penny. Complete the chart on the next slide and answer the questions. FILL OUT THE CHART DROP d (m) t (s) 2 a (m/s ) 1 2 3 1 2 3 How could you improve your results (at least 2 examples)? Pre-Class Friday 10-12-12 Due to the aerodynamics of the Space Shuttle, it is often called a _____. a. b. Flying brick Monument of engineering c. Paper rocket d. Weightless wonder Above and Beyond Activity Astronautical Develop technology for use in space exploration Specialize in propulsion, guidance and control systems, structural design, and defense systems Like aeronautical, safety is a premium… people’s lives are depending on your work Pre-class Monday 10-15-12 There are two possible answers to the following problem: What is half of two plus two? Give me both of them. Pre-Class Monday 3-5-12 In spacecraft design, list three things you need to know before you begin your plan. Pre-Class Tuesday 3-6-12 Write: “Guest Speaker: Matthew Hitt, UAHuntsville Aerospace Engineer.” Pre-Class Wednesday 3-7-12 Assume the performance test was challenging, what was the biggest challenge in it? Explain. Pre-Class Thursday 3-8-12 What is the name (acronym) of the professional organization for Aerospace Engineers? Pre-Class Friday 10-5-11 Which of the seven black shapes are identical to the red one? Pre-Class Tuesday 3+8=11 Write: “Continuing Performance Test.” Pre-Class Friday 10-1-10 Today’s date is a binary number (10110). What is the decimal (base 10 number)? Remember: there are 10 kinds of people in the world: those who understand binary and those who don’t. Pre-class Wednesday 2-29-11 All months have 30-31 days, except for February which has a changing number of days. Explain why today is the last day of the month and not yesterday. Believe it or not, it was designed this way. Designing a Leap Year The next leap year will occur in 2016. In the Gregorian calendar the following three criteria must be met to be a leap year: – It is evenly divisible by four; – If it can be evenly divided by 100, it is NOT a leap year, unless; – The year is evenly divisible by 400. Then it is a leap year. This means that years 1800, 1900, 2100, 2200, 2300 and 2500 are NOT leap years, while year 2000 and 2400 are leap years. In the Julian calendar–there was only one rule: any year evenly divisible by four would be a leap year. This calendar was used before the Gregorian calendar was adopted.