# Tag Info

10

Firstly tl/dr - if you need to ask, then this will go RUDE* and may take out your garden, pets, family, etc... From someone who knows: it's gonna go "boom" and spray propellants at about 3000 Kelvin or more So, you need to think about what you have here - Pressurised propellant will find a way out if it can. And then it will ignite. Rapidly. A threaded ...

5

Anton must really love chemistry or pain. NASA's CEA is a robust tool for analyzing combustion thermo-chemistry which was developed by the same Gordon & McBride mentioned in Anton's answer while they were working at NASA. They also make MATLAB wrappers for the thing, but I'm not sure where to find a publicly available option. It will save you a ...

5

I managed to reproduce your error. When it says "^1/2" in the equation, you are supposed to take the square root of the quantity in the parentheses. You are not doing this. You are dividing by 2 instead. 0.0906 / 169.34 = 0.000535 365659 / 38.64 = 9463 .000535 * 9463 = 5.063 5.063 / 2 = 2.53 It should be .000535 * (9463)^(1/2) = 0.052 .000535 * 97....

4

That equation as you give it with the values you supply is a bad mish-mash of units. It's painful to do this in the English system, but gather your courage, we can get through it. You must specify the flowrate in $\frac{slugs}{sec}$. Yes, slugs, the real engineer's unit of massTM. A slug is 1 $\frac {lbf - sec^2} {ft}$ and equates to ~ 32.2 lbm. So ...

3

You will need to write a solver for the incomplete combustion of your propellant. This can be done by hand, but I recommend writing a program to implement it. These days, such calculations are primarily done by solving for the maximum entropic state of the system (the system being the mixture of reactants at the chamber temperature & pressure). The ...

3

$R$ and $g_c$ each have a foot component in their units; therefore the feet cancel out when $R$ is divided by $g_c$. $P_t$ is in pounds per square inch; since you're dividing by that, it's effectively units of square inch per pound, which is where the square inches in the answer comes from. The rest of the unit cancellation is confusing because of the use of ...

1

One of the online versions of this book, the one found here, includes an "Additions and Corrections" page. The fifth bullet point on this page states: In the example calculation, I think there may be arithmetic errors in the calculation of the coolant flow gap. Readers are strongly encouraged to redo all calculations for themselves. I have now seen ...

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