Reflections

Boeing Field Reflection

In Boeing they build each part of the airplane in different parts of the world, than they transport those parts with a cargo airplane Boeing 747 Dreamlifter to the Boeing Field, when the parts are there they put all together and build the airplane. When I looked from outside I did not notice that was so big, but when I got inside I could see how was that, I almost could not see the end of the first tunnel, but when we got the elevator we go at the third level, and I could see all the airplanes being building from the top and was possible to see all the four sides of the build, and a realize how big was. There we saw lots of airplanes being build all together, and we can see how precise all factories need be to dovetail all pieces together, has to be exactly otherwise will all fall apart.

That trip was good but did not change a lot my perception of carrier, because I want to go in the military career and be a pilot so don’t make so much different.

I liked a lot this field trip, was really interesting to see how they build the airplanes and look all those new planes, and new models of planes, but how the guy present got kind slow and not so exciting how I was expecting, but anyways I liked that experience and I think is really important for the course, we have the opportunity to see all those planes, and we could see in a little museum some parts of the airplane really close and see how they are.

Aviation Reflection

 I came specific to Rick Hansen Secondary School from Brazil because of this course, and I’m really happy about that, because the Aviation 12 was so good course and we learned about so many things, first how are the shape of the wings, I never thought about that, and now I understand how important this is, than we learned about the engines and how they work, after we study about the weather, was so cool, and we learned so much stuff that I never thought about, than in the end we did the navigation part, was really hard, we had to use maps, and different ruler, but was nice too. The most important is even if we don’t be in the aviation career, we can still use those entire things in our life, and so after all, this course was a really important thing in my life. I liked do all the stuff that we did in this class was really good experience, we did fun things too

I now know a lot about aviation, and I want follow the military career, I want to serve the Brazilian air force, I always thought about that, when I had 14 year old I tried to go on the air force high school in Brazil, but I could not pass the test because was really hard, but now I’m more enthusiastic to be a fight pilot, and represent my country, when I back to Brazil, I will do the test and hopefully pass.

I think I did well on that, I study for the tests and did the projects, was really fun build and fly the aero model, and I think I did good on that, now I want to build more kind of them, is a lot fun. In my house I bought my own simulator and practice a lot to the final test, even I had to play with the keyboard and the mouse, I got used to the instruments and how to fly, now I going to do the final test, that will be fly to Nanaimo, I think I will do well.

Wing Project

Daniel Bernoulli 

Daniel Bernoulli (Groningen, 8 February 1700 - Basel, March 17, 1782) was a Dutch mathematician, member of a family of talented mathematicians, physicists and philosophers. It is particularly remembered for his applications of mathematics to mechanics, especially fluid mechanics, and the first to understand the atmospheric pressure in molecular terms.

He was a contemporary and close friend of Leonard Euler. He moved to St. Petersburg in 1724, as professor of mathematics, but was unhappy there, and an illness in 1733 gave him an excuse to withdraw. He returned to the University of Basel, where he held the chair of successive medicine, metaphysics and natural philosophy until his death.

Daniel Bernoulli.

Bernoulli principle

It was exposed by Daniel Bernoulli in his book Hydrodynamics (1738) and expresses an ideal fluid (no viscosity or friction) regime in circulation for a closed conduit, the energy that holds the fluid remains constant along its route. The energy of a fluid at any point consists of three components:

Kinetics: the energy is due to the speed that has the fluid.

Gravitational potential: is the energy due to the altitude that has a fluid.

Energy flow: is the energy that contains a fluid due to the pressure you have.

The following equation known as "Bernoulli equation" (trinomial Bernoulli) consists of these same terms.

Incompressible flow equation

To apply the equation should make the following assumptions:

Viscosity (internal friction) = 0 That is, it is considered that the current line on which is applied in a zone 'non-viscous' fluid.

Constant flow

Although the name is due to Bernoulli equation, the form outlined above was first presented by Leonhard Euler.

Where;

v is the fluid flow speed at a point on a streamline,

g is the acceleration due to gravity

z is the elevation of the point above a reference plane, with the positive z-direction pointing upward – so in the direction opposite to the gravitational acceleration,

P is the pressure at the chosen point, and

p is the density of the fluid at all points in the fluid.

Lift Equation

The lift equation is L= ½dv²sCL.

Where;

            L is stands for lift,

            D is stands for density of air,

            V is stands for velocity,

            S is stands for surface area of the wing,

            CL is stands for Coefficient of lift.

How does it applied to lift?

Density of air

Higher Density means more air particles in the air and less density means less air particles in the air. If the air is denser the wing will create more lift because there are more air particles moving on top of the wing.

Illustration of the Air density in different altitudes.

Velocity

If the plane is going faster that means more air particles are moving over the wing in less time generating more lift. If the plane is going slower that means there are less air particles moving over the wing in more time, creating less lift. This is why planes run on the runway to take off.

Area of the wing

 If the area of the wing is larger it can hold more air particles and create more lift. If the area is smaller it will hold fewer particles on the wing which will result in less lift. This is why gliders have long wings and they create lots of lift without any thrust.

Coefficient of lift

 It depends on the shape of the wing. If the wing has deep camber it will create more lift because it forces the air move faster over the wing. If you have a square shape wing it will create no lift at all because all air will hit the front and there will be barely any air flowing on top of the wing. Smooth wing creates more lift because the air particles will able to move freely and faster.

Importance of Airflow

The wing should have faster moving air on the top of wing, so there can be low pressure and high pressure difference. The wing should be smooth and clean because it is important to have laminar air flow on the top of the wing; it helps in creating more lift. Things such as ice and rust on the wing can destroy the lift and increase the stall speed. If the wing is not smooth it can slow down the air on the top of wing causing turbulence and it will destroy the lift.

           

 Wind acting on the wing.

Improvement in Design

By increasing the surface area of the wing we could of got more lift because there will be more air particles moving on wing resulting in the lift. We could improve it by increasing the camber and smoothing the wing more, so there will be less parasite drag.

Characteristics of the wing

                  Deep camber.

                  High Lift.

                  Low speed.

                  Thick wing section.

                  Suitable for transport and bombers. 

How lift is applies to Bernoulli's principle?

There are stream tubes in the air. The amount air that enters from the front of tube the same amount wants to leave from back of the tube. If you place wing in tube there is less room for air to move, so the air start to move faster on the top of the wing because of the camber and it create low pressure on the top and because the wing is straight from the bottom and the air does not speed up a the bottom which create high pressure. The low pressure on the top of wing want to suck the wing upwards creating lift. Low pressure on the top of wing also decreases the temperature which can lead up to icing on the wing. One of main reasons to increase stall speed and lose in lift is icing. If you fly in clouds, you increase the chances of icing on the wing because of the moisture in the air. The high speed moving air on top of wing creates low temperature and it end up freezing all the water vapor in the air over the wing. Same thing happens in a carburetor, as the mixture in carburetor speeds up it freezes and can lead up to icing.

Data and Observation

Straight level = 4.0 to 4.5 g

15° AOA = 5.3 to 6.0 g

We observed that in straight level flight wing generates around 4g of lift. However, if we increase the angle of attack about 15° wing starts to generate around 5.3g of lift. Also, as we increase the angle of attack the wing start to shake and turbulent air    start to form at trailing edge of wing. By using the thread on the top of wing we were able to see wing tip vortices.                                            

Lift increased as we changed the angle of attack because as we increase AOA there is less room on top for air to move, therefore air start to move faster which creates low pressure over the wing and high pressure under the wing. By having more low pressure on top of wing and high pressure under the wing it creates more lift. If you increase AOA too much, your plane can stall because there will be on air moving over the wing, the air will hit under the wing and it won’t go on top of the wing. By increasing the angle of attack more turbulent air also start to form. As the boundary layer reaches the center the wing air start to lose its speed due to skin friction of the wing. Due to lose in air speed, turbulent air start to form at trailing edge of the wing, it start to destroy lift, and makes wing shake. The wing also experienced wing tip vortices. The vortices were created because the air on the top of the wing wants to move inwards, while the air on bottom of the wing wants to move outwards. When the air flows unite at trailing edge they start to flow contra-wise and it end up creating vortices.

What else is the Bernoulli principle applied?

Cars

Carburetor

For example, inside a carburetor is a venturi: 

Picture of a carburetor cut in half. Daniel Bernoulli

The venturi apparatus is created by Giovanni Battista venturi for measuring flow velocity and flow rate of a liquid through the incompressible pressure variation during passage of the liquid through a tube of wider section and then the other narrower section. This effect is explained by Bernoulli's principle and the principle of continuity of mass. If the flow of a fluid is constant, but its flow area then decreases necessarily, its velocity increases. 

 

Venturi’s Principle

Airfoil

In sports cars such as Formula 1, engineers use the very principles of aerodynamics to make the car can have both stability and good performance on the track, both on the straights and in the corners. For these cars are very fast, they are designed to reduce air resistance and increase the downforce generated by the body and its attachments, causing them to be really "stuck" to the floor. To this end they use the airfoils, plates external side deflectors and diffusers as a measure to reduce air resistance.

Formula 1 car’s, the rear wing generates downforce to the rear of the car

The aerofoils operate on the same principles of operation of the wings of an airplane. The only difference is that airplane wings give support while in cars, more precisely in Formula 1, provide a down force that holds the car on the ground.

Closer picture of the airfoil. National Museum of the United Arab Emirates

The Airfoils does exist in sport cars as well, but can increase the fuel consumption of the car. Most often only serves to aesthetics, because it has no significant influence on vehicle performance.

Buildings

The Bernoulli’s principle can be applied in buildings too, this wing-shaped building is a National Museum of the United Arab Emirates, and show the history, culture and more recently the social and economic transformation of the country. The museum features five towers shaped wings which protrude a lot of landscape (the landscape was created artificially) where the buildings are. The towers act as thermal chimneys, creating currents of cooling without electricity. Fresh air is captured and released into the air of the museum.

 National Museum of the United Arab Emirates

But you don’t want your building has a wing shaped unintentionally, because when the wind blow, would do a lot of tension on it, and could destroy the building faster and in other cases like a bridge is the same thing, you don’t want that flowing away, so is important know about the Bernoulli’s principle even if you don’t want to make a wing.

References

http://en.wikipedia.org/wiki/Daniel_Bernoulli

http://en.wikipedia.org/wiki/Bernoulli's_principle

http://www.infoplease.com/encyclopedia/science/bernoulli-principle.html

http://en.wikipedia.org/wiki/Carburetor

http://hyperphysics.phy-astr.gsu.edu/hbase/fluids/airfoil.html

Conclusion

The Bernoulli’s principle is really important for an airplane engineer because is necessary to create a good airplane, to flight better and do not use so much gas, also is used in different cases like in big buildings because if it is made a building with a shape of a wing could be a problem because will create a lot tension in this build because the air flow and will destroy that.

What I learned is the shape of a wing is the most important part of the airplane, depends how is it, the airplane can change a lot the flight characteristics, and this determine what kind a airplane, and what is your propose.