Recent content by LT72884

On some yes

Thats what i thought. Though i have been informed differently a few times, and each time they do have a good explanation too. Im hoping the other user, i think its Russ, will chime in. I love learning and this is good stuff

Ok, so i have a high powered rocket i made and it hits about 420 m/s At low mach numbers, most the drag is due to skin friction, hence why you can solve for the Cd based on the Re and geometry alone (Dr. Gerald M. Gregoreks work shows this) However, as soon as you hit higher mach numbers...

google must round differently is all. There 32 was 90.. But really it shold be 89.6 oh well

ok, so if my launch day was 32C (90F) and the change in temp was 1 C, meaning the new temp was now 33C, that would mean the temp was 91.4 degrees F? Or is the change in temp only referring to the material itself since thats the Cp we are using? so whatever tmep the material was at the beginning...

i do know that it also uses pressure drag(Cdp) at higher machnumbers. but doesnt pressure drag end up being simplified down to Fd once you know the Cdp?

correct, i do know this equation. and i THOUGHT that is what i used.... or maybe i didnt haha. Yes, 1 degree increase of C is 1 unit increase of kelvin. So if my dT is only changing by 1 k, that means the temp change was 1 C as well, meaning the increase was from 32 C to 33C based upon the...

32 f is 273k It seems that for every 2 degrees f, k increases by 1. So 2:1 from F to k

Well, openfoam uses it for 210m\s and i know HISA uses for 420m\s when i run cfd What formula would you recommend for high mach numbers?

So what would be the best way to convert to F so i know what the temp increase is? Thanks

Fd = (0.5)(rho)(A)(Cd)(v^2) Im just using basic drag, and assuming all the drag force is converted to work, the allowing all the work to be converted to heat

Ok, so i have a question, and an approach to my question. Am i going in the correct direction? Here si the question: I have a high powered rocket i made. It sometimes hits mach 1.9. I would like to calculate the heat generated from going that fast so i can test other materials. Here is what...

correct, there is no controversy :) i thank you for your help aand guidance. it is much appreciated.

correct, i understand what you are saying :) but rocket motors are so small that 3.5g of changing mass is almost negligible. yes, this is for zero drag modeling only. I was just mentioning i can find Cd various ways etc. ill have to look at your reply again. I did find a book online last...

this is just for simple estimates. I do know i would have to integrate etc, but for simplicity, you can use the big 3 to solve for velocity. Vf = Vi = at Vi = 0 so Vf is acceleration * time i know the acceleration of the rocket motor i9n basic simple terms a= (Thrust - weight)/mass according...