Water Rockets - Aerodynamics

At its simplest, a water rocket is basically an upside down fizzy drinks bottle, which has had a ‘nose’ cone and some fins added.

The nose cone 
The job of the nose cone is to make the rather snub-nosed end of the fizzy drinks bottle more aerodynamic. Also if you have ‘payload’ on your rocket, or a parachute mechanism, this is probably where it will be placed.

The fins
Others might disagree, but I think the fins are the parts of a rocket that really give a rocket its character. Technically, the fins are important for ensuring that the rocket flies smoothly

Once we have added the fins and the nose cone, we have something which looks like a rocket. But how do we make it go like a rocket?

First we need to add some water, and some kind of release mechanism, that will keep the water in the bottle, until we choose to release it. The water will then leave the bottle through its nozzle.

Typically the bottle will be between about one quarter and one third filled with water.

Launch 
To launch the water rocket, we need to pump air into the rocket: this provides the energy for the launch. As the air enters, it bubbles up through the water and pressurises the ‘empty’ space above the water. You can see that the release mechanism has to be really quite clever, allowing air into the rocket, while not allowing the water to escape until we activate a trigger.

Aim: To look at the 4 main forces of flying and how these can be overcome.

Hypothesis: I think that.......

Method: Working in pairs you are going to make a paper wing and experiment with it.

1. Make a paper wing out of A4 paper 
2. On the field you will need to record and observe how 5 different changes affect the way it flies.

Plane type	How does it behave?	Time ( secs)
Paper sheet, drop	gravity	3
Paper with fold down middle, drop	falls down quickly	2
Paper with fold and 1 paper clip, drop	falls gently	4
Fold, 2 clips, rudder, drop	falls normaly	2
Fold, 2 clips, rudder throw	it ailed	3

Brainstorm: What are the forces acting on an aircraft?

1.   Drag
2.   Lift
3.   Gravity / Weight
4.  Thrust

How can we overcome some of these forces?

Force	Their effect on a plane	How to overcome them?
Gravity / Weight	pulls it down	makes things light
Drag	makes it go solwer	making something go faster, streamline
Lift	makes it go up	gravity & weight
Thrust	pulls it away	powerful engine

Spheres

Spheres

-Biosphere (Life)

All Surroundings
Known as the thermal of the earth

-Lithosphere (Ground)

30% of earths surface is made of land
Layers of the earth, the rigged part.

-Hydrosphere (Water)

70% of earths surface is made of water
Is natures liquid and cover most of the earth. 

-Atmosphere (Air)

78% Nitrogen 21% Oxygen 

A layer of gases and is hold earth with gravity. 

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1.     A tree is blown down by wind            

            Biosphere - Atmosphere                

2.     A person gets caught in the rain

                  Biosphere - Hydrosphere

3.     Hail damages a sugar cane crop

                 Hydrosphere - 

4.     Air next to the ground becomes warm 

                      Atmosphere - Lithosphere

    

5.     Water vapour condenses

                  Hydrosphere

6.     Lightning strikes a park ranger

              Atmosphere 

7.     A flash flood forms

                Hydrosphere

8.     A puddle seeps into the ground

                Hydrosphere - Lithosphere

9.     Cumulonimbus clouds form

                       Atmosphere

10.   A tornado destroys a zoo

                       Atmosphere