Water Powered Rocket
The main differences in my designs are the fin shapes and sizes, and the transition cone size.
I changed those so much because they seemed to be making the biggest differences.
Making the cone transition smaller made the weight decrease. The fins changed the static margin and made it higher.
Notes: The parachute will cause a drag. Lift is a side force used to stabilize and control the direction of flight. Thrust produces lift-off or upward movement of a rocket. For Lift- off to be achieved thrust must exceed weight. Weight is related to the objects and other things on the rocket. It is the gravitational pull to the ground. There are three key axes that define this movement: Roll (longitudinal), Pitch (lateral), and Yaw (vertical). Since a rocket always rotates about its center of gravity, these axes are typically drawn to meet at the center of gravity. The longitudinal (roll) axis runs lengthwise down the rocket. The rockets tends to twist about this axis.
The lateral (pitch) axis runs side-to-side. Think of being on a seesaw and moving up and down. That up and down movement is your pitch and it occurs along a lateral axis.
The vertical (yaw) axis runs top-to-bottom. On a rocket, yaw is very similar to pitch except that the nose moves side-to-side.
The shape of the nose cone is used to help reduce drag. Also the nose cone may protect the payload, guidance, and recovery system for the rocket.
The fins of the rocket are important for maintaining stability. Without the fins the rocket would rotate uncontrollably about all three axes.
The frame, or body, helps to maintain the structural integrity of the rocket.
Propulsion System - In the picture it is easy to see that the rocket consists of mostly the propulsion system. The propulsion system must produce enough thrust to overcome weight and drag to achieve lift-off. There are two main types of rocket propulsion: solid and liquid fuel. The above picture is a liquid fuel propulsion system. Both types of rocket propulsion are still used.
Guidance System - A guidance system may be a combination of sensors, computers, GPS, and communicators. The guidance system has two main roles during the launch of a rocket; to provide stability for the rocket, and to control the rocket during maneuvers.
Payload System - Payload is what the rocket is carrying. The payload depends on the rocket's mission. The payload could be a satellite, a human, or even an explosive device. Many rockets were designed so that different payloads could be carried with the same rocket.
Recovery System -the recovery system is one of the most important systems. Rocket recovery systems are an important aspect for safe rocket launching. A rocket recovery system should allow the rocket and possibly payload to land undamaged.
- Roll is a twisting motions about the roll (longitudinal) axis. Roll movement is not really a problem on a water rocket since it does not tend to alter the rocket's flight path.
- Pitch refers to an up and down movement of the rocket's nose. This movement can take the rocket off of its intended flight path and could result from a gust of wind. Careful attention to the location of the center of gravity and center of pressure will ensure pitch stability.
- Yaw refers to the side to side movement of the rocket's nose. This movement can take the rocket off of its intended flight path and could result from a gust of wind (very similar to pitch). Careful attention to the location of the center of gravity and center of pressure will ensure yaw stability.
The most important method for controlling stability around the pitch and yaw axes is to control the location of the center of gravity and center of pressure. The distance between the center of gravity and center of pressure is known as the static margin. Changing the static margin changes the stability of the rocket. The best size of the static margin is based on the bottle size used. A good rule of thumb is that the static margin should be greater than or equal to the bottle diameter (although this is very hard to do with a bottle rocket). A key point to remember is that the center of gravity should be closer to the nose of the rocket than the center of pressure.
The finished product:
I launched the rocket
My time was 3.88 seconds.
If I was to refine the design: I probably would add more water and make the tube bigger so that the parachute would be able to come out easier. I would also need to change the cone that is holding nose (ball) because it made my rocket go the wrong way.
If I was to mass produce my design: It needs to be durable of a crash so that it can be used over and over again.