prospect_1
Member
- Joined
- Oct 17, 2014
- Messages
- 6
- Reaction score
- 0
Hello,
First post! So, for a school project, I am looking to decrease the total impulse of a Rattworks H70 Hybrid motor by decreasing the volume of the oxidizer chamber. I'm hoping to be able to get to the desired impulse with only two static tests, so trial and error is not really an option.
I'm having trouble figuring out the exact volume of oxidizer to remove. I don't want to just assume its proportional but I'm not sure what else to do. I read somewhere that the oxidiser-to-fuel ratio varies along the fuel grain, which makes things more complicated. Can anyone point me in the right direction as far as figuring out the math behind my problem? Here is some info that might be helpful:
Diameter: 29mm
Length: 18" (457mm)
Average Thrust: 15.4 lbs. (68.5 N)
Peak Thrust: 34.5 lbs. (153.5 N)
ISP: 167.3 sec.
Burn Time: 2.57 sec.
Weight (Empty): 207.5 g
Weight (Loaded w/o N2O): 251.5 g
Weight (Loaded w/ N2O): 352.7 g
N2O Weight (750 PSI): 0.223 lbs. (101.2 g)
Tank Volume: 8.29ci (135.8cc)
Polypropylene fuel grain
Any help would be greatly appreciated!
First post! So, for a school project, I am looking to decrease the total impulse of a Rattworks H70 Hybrid motor by decreasing the volume of the oxidizer chamber. I'm hoping to be able to get to the desired impulse with only two static tests, so trial and error is not really an option.
I'm having trouble figuring out the exact volume of oxidizer to remove. I don't want to just assume its proportional but I'm not sure what else to do. I read somewhere that the oxidiser-to-fuel ratio varies along the fuel grain, which makes things more complicated. Can anyone point me in the right direction as far as figuring out the math behind my problem? Here is some info that might be helpful:
Diameter: 29mm
Length: 18" (457mm)
Average Thrust: 15.4 lbs. (68.5 N)
Peak Thrust: 34.5 lbs. (153.5 N)
ISP: 167.3 sec.
Burn Time: 2.57 sec.
Weight (Empty): 207.5 g
Weight (Loaded w/o N2O): 251.5 g
Weight (Loaded w/ N2O): 352.7 g
N2O Weight (750 PSI): 0.223 lbs. (101.2 g)
Tank Volume: 8.29ci (135.8cc)
Polypropylene fuel grain
Any help would be greatly appreciated!