Hello all, I am very new to the domain of amateur rocketry and I have recently joined a university team to build a model rocket that is to be run using Solid Rocket Motor.
So now I am completely confused on even how to start and I had read through a few of the previous posts and discussions in this forum to help me but I don't think I got what I needed. Plus to get us started and the entire team being very new to this type of thing, almost all of us are quite confused about how to start. So the basic task that we started with was to do a trial design of a Solid Rocket Motor and we had chosen APCP as the propellant. Now the task was to simulate using a program written in any language, the process of what happens during the static test. We were told to simulate the thrust vs time curve, the impulse curve over time, and then the pressure within the combustion chamber with respect to time. I think this was a very basic task to get us started but I have no idea how to start.
So take for example the APCP as the propellant. I read a few basic things about it and then I chose a specific design of the grain. Now how do I choose what is the core diameter and the diameter of the motor? I cannot just choose a random value cause the results will make no sense. Then I looked and went through all the required equations for simulations, but then I came to this iterative problem that I needed to first know the chamber pressure and temperature. Using that I can somehow proceed to the next steps and use the program to iteratively find the next values. But then how do I even know these values to begin with? I don't know where to look for the data. Then for all the equations, I see a lot of variables that are specific to the propellant like the burn rate, and many other parameters. Where do I get these things from? I don't even have a rough guess on what the value should be.
Can someone help me out on this by probably directing me to a place where there is not just theory and equations, but a place where a real-life initial sizing is done for these motors?
I know for a fact that ProPEP3 and a few other software already exist for this but I don't really want to use them cause I want a deeper understanding of what is happening. I played with the software but I don't really have a feel of what or where the results come from.
I would really appreciate any help. I hope you can understand the fact that I am asking for help of a sort such that we are a new university team working on this and we need some very basic steps to even start our journey.
Vicknesh
So now I am completely confused on even how to start and I had read through a few of the previous posts and discussions in this forum to help me but I don't think I got what I needed. Plus to get us started and the entire team being very new to this type of thing, almost all of us are quite confused about how to start. So the basic task that we started with was to do a trial design of a Solid Rocket Motor and we had chosen APCP as the propellant. Now the task was to simulate using a program written in any language, the process of what happens during the static test. We were told to simulate the thrust vs time curve, the impulse curve over time, and then the pressure within the combustion chamber with respect to time. I think this was a very basic task to get us started but I have no idea how to start.
So take for example the APCP as the propellant. I read a few basic things about it and then I chose a specific design of the grain. Now how do I choose what is the core diameter and the diameter of the motor? I cannot just choose a random value cause the results will make no sense. Then I looked and went through all the required equations for simulations, but then I came to this iterative problem that I needed to first know the chamber pressure and temperature. Using that I can somehow proceed to the next steps and use the program to iteratively find the next values. But then how do I even know these values to begin with? I don't know where to look for the data. Then for all the equations, I see a lot of variables that are specific to the propellant like the burn rate, and many other parameters. Where do I get these things from? I don't even have a rough guess on what the value should be.
Can someone help me out on this by probably directing me to a place where there is not just theory and equations, but a place where a real-life initial sizing is done for these motors?
I know for a fact that ProPEP3 and a few other software already exist for this but I don't really want to use them cause I want a deeper understanding of what is happening. I played with the software but I don't really have a feel of what or where the results come from.
I would really appreciate any help. I hope you can understand the fact that I am asking for help of a sort such that we are a new university team working on this and we need some very basic steps to even start our journey.
Vicknesh
