Part 1: Explore the components of a rocket.
If you are going to build a rocket,
Part 1: Explore the components of a rocket.
If you are going to build a rocket, you need to know what parts make them up and what they do. Log onto the Apogee website (https://www.apogeerockets.com/Tech/Parts_of_a_Rocket). This site shows two diagrams with the external and internal parts of a rocket. If you click on a part it explains a little bit about its purpose and function. Use this website to explain the function and sketch each of the following rocket parts.
1.Body Tube
a.Function:
b.Drawing
2.Nose Cone and Shoulder
a.Function:
b.Drawing
3.Fins
a.Function:
b.Drawing
4.Launch Lug
a.Function:
b.Drawing
5.Engine Mount
a.Function:
b.Drawing
6.Centering Rings
a.Function:
b.Drawing
7.Engine Block (Thrust Ring)
a.Function:
b.Drawing
8.Shock Cord
a.Function:
b.Drawing
9.Recovery Device (Parachute)
a.Function:
b.Drawing
10. Recovery wadding
a.Function:
b.Drawing
Part 2: Design the first draft of your rocket using OpenRocket Simulator.
1.Start the Simulator. Go to OpenRocket simulator (http://openrocket.info) and download the program. You will use this program to precisely design each part of your rocket. Then you will adjust certain parts and features to see how it affects the rocket’s performance. Once you settle on a design, you will construct your actual rock as close as possible to these specs. Make sure you save your rocket and take screenshots of all your specifications so that you can accurately reproduce your rocket in real life.
2.Nose Cone.
a.The first step in designing your rocket is to create a nose cone. To do this, select the nose cone icon from the component box. Choose a shape from the drop down menu. Each of these shapes will have a slightly different effect on stability and drag of the rocket (we will talk more about this in lab 2).
b.For this project, we will be using either an NC-60 or NC-80 cones, which have a base diameter of 4.16 cm and 6.6 cm respectively. You will need to click on the “shoulder” tab to add a shoulder that fits inside the body. Since the inner radius of a BT-60 and BT-80 tubes are 4.05 cm and 6.5 respectively, this will have to be the diameter of the shoulder.
3.Body Tube.
a.Next create a body tube, which is basically the foundation of any rocket. For this project we will be using BT-60 and BT-80 tubes, so you will have to set the Inner Diameter to 4.05 cm and Outer Diameter to 4.16 cm for BT-60, or Inner Diameter to 6.5 cm and Outer Diameter to 6.6 cm for BT-80. However, your body can be up to 36 inches long (each lab kit contains two body tubes that can be combined using the coupler tube in the lab kit.
b.Notice that in your body and nose cone you will see a blue center of gravity point (CG) and a red center of pressure point (CP). The exact location of these along with the stability coefficient is written in the right corner of your rocket schematic window. The stability coefficient is very important. If it is too small or too large, your rocket will not be stable.
4.Engine Mount.
a.The first step to creating an engine mount is to add an inner tube. Make sure “body tube” is highlighted in the box at the top left, then select “inner tube” from the component list.
b.This tube will need to fit a D-engine, which has a diameter of 24 mm (2.4 cm) and the outer wall should be roughly 2.46 cm. Set the dimensions accordingly. The length of a D engine is 7 cm, so make this be the length of the tube.
c.To finish the engine mount you will also need two centering rings to fit it in the tube and keep it place and an engine block to keep the engine from flying into the middle of the rocket and burning everything up. See if you can adjust the parameters of the centering rings and engine block so that it fits perfectly inside your rocket.
5.Fins.
a.To start designing your fins, make sure “body tube” is highlighted in the box on the top left. Then select either trapezoidal, elliptical, or freeform from the components menu depending on which style of fin you want to work with. Notice that as soon as you add the fins, the center of pressure point moves from the nose cone to the rear of the rocket. You’ll come to learn that a key ingredient of stability is that your rocket’s center of pressure (CP) is below the center of gravity (CG).
b.In the drop down menu, select the number of fins you want your rocket to have. There are many more parameters. Experiment to see what they all mean. Most importantly, see how changing these different parameters affect stability, CG, and CP locations.
c.If you picked freeform, select the shape tab and begin finding the shape of the fin you are looking for. Double click on the line to create another corner. Play around, mess with the lengths. Again, watch how the shape and size of the fins affects the location of the center of pressure and gravity and stability coefficient.
6.Launch Lug.
a.To add a launch lug, again make sure “body tube” is highlighted in the box on the top left. Then select “launch lug” from the drop down.
b.The inner diameter needs to be at least ¼ inch to fit over the launch rod. Find out what that is in cm and set accordingly.
c.It is typically fine to set the launch lug in the middle of the rocket.
7.Parachute.
a.To add a parachute, again make sure “body tube” is highlighted in the box on the top left. Then scroll down in the component box to “mass objects” and select parachute.
b.There are a lot of parameters for these, but we will spend more time figuring out how big it needs to be to keep your rocket safe in a later lab. For now just make sure it fills up the diameter of your rocket.
8.Shock cord.
a.Add a shock cord in the same way you added the parachute.
9.Motors:
a.Click on the “motors and configurations” tab at the top of the screen.
b.To the left you will see a drop down tab that says “motor mounts.” Select “inner tube” since this is what you will be using for your motor mount. Then click the “New Configuration” tab.
c.In the box below you will see two columns. Double click where it says “none” under “inner tube. This will create a drop down menu of motors. Filter this menu just to show estes motors, and once you have estes motors select the one we will be using for this project (D12).
Objective 3: Use simulations to maximize rocket design and performance.
1.Click the Simulation Tab at the top.
2.Click “New simulation” and name it “Baseline.” Then click “simulate and plot.” A window will open asking you what you want added to your simulation graphs. Select altitude and vertical velocity (unselect vertical acceleration). Then click “plot.” Print the graph and put your data in the table below.
3.Choose three different fin designs and do a simulation for each one keeping all other parameters constant. What were the different altitudes for each design? Put the values in the table below.
4.Find three more parameters that you can change in the design of your rocket that might get you faster and higher than your baseline simulation. Run simulations for each of these and input the data in the table below. The idea here is that like an engineer you are experimenting with your design to find the best possible result. Print each simulation and attach it to the lab report. Save the file, and take screenshots of each part of your design so that you can faithfully recreate your rocket once you begin building.
Simulation
Parameter adjusted
Max altitude
Max vertical velocity
Time until touchdown
Baseline
None
Fin 1
Fin shape adjustment
Fin 2
Fin shape adjustment
Fin 3
Fin shape adjustment
Adjustment 1
Adjustment 2
Adjustment 3
Post Lab Questions
1.From your experiments in the simulations above, what variables seem to affect the performance of your rocket most ( for example length, nose cone shape, fin shape, others?) Name at least three variables and explain the effect they have on performance (altitude, speed, etc.)
2.Pick one of the following rockets in the history of rocketry: V2, Titan, Gemini, Saturn V, Apollo, Space Shuttle, SpaceX Falcon and write about 500 words (typed) answering the following questions:
a.What was the purpose of this rocket/spacecraft? Why was it built?
b.When was it designed and by whom?
c.What are some interesting facts about the history, design, and use of this rocket/spacecraft?
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