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→Center of Pressure
The center of pressure is the location at which we can model the aerodynamic effects as acting. In other words, the drag on the rocket acts at this point. If the center of pressure is below the center of gravity, then the downwards force of drag will keep the rocket upright, while a center of pressure above the center of gravity will flip the rocket. A CP and CG at the same point will create a neutrally stable rocket, meaning that any incidental forces could theoretically spin it. This makes the distance between the CP and CG critically important for determining whether flight will be safe and successful.
The center of pressure is the location at which we can model the aerodynamic effects as acting. In other words, the drag on the rocket acts at this point. If the center of pressure is below the center of gravity, then the downwards force of drag will keep the rocket upright, while a center of pressure above the center of gravity will flip the rocket. A CP and CG at the same point will create a neutrally stable rocket, meaning that any incidental forces could theoretically spin it. This makes the distance between the CP and CG critically important for determining whether flight will be safe and successful.
The main tool we have to change the center of gravity is the size of the rocket's fins - larger fins will bring the center of pressure lower down on the rocket, increasing its stability.
The main tool we have to change the center of pressure is the size of the rocket's fins - larger fins will bring the center of pressure lower down on the rocket, increasing its stability.
To calculate center of pressure, you can use the Barrowman equations ([http://www.scalerocketry.com/equations/barrowman.htm link to a slighty confusing example]) or the [https://www.apogeerockets.com/education/downloads/Newsletter18.pdf cardboard cutout method].
To calculate center of pressure, you can use the Barrowman equations ([http://www.scalerocketry.com/equations/barrowman.htm link to a slighty confusing example]) or the [https://www.apogeerockets.com/education/downloads/Newsletter18.pdf cardboard cutout method].
Another way to determine the CP of your rocket is to use a program like OpenRocket or RockSim. Both of these programs take all the information you input about your rocket and input into the Barrowman equations for you.
=== Calibers ===
=== Calibers ===