- Joined
- Jun 7, 2011
- Messages
- 273
- Reaction score
- 305
To All:
Inspired by lr64's 'is it possible to go supersonic on an Estes black powder motor' thread:
https://www.rocketryforum.com/threa...rsonic-on-an-estes-motor.186994/#post-2598528
And Flight Systems Incorporated (FSI) minimum diameter F100 and F7 rockets I built and flew when I was 16-18 years old;
I've asked the following question. Is it possible to go supersonic (exceed Mach 1) using Estes black powder motors? A corollary question is; is it possible to exceed 10,000 ft using Estes black powder motors?
When I was 16-18 years old, I'd fly minimum diameter multi-stage FSI F100 and F7 motors. A photo of one is below, including a young yours truly. The photo is from something like 1975-1977. The rocket is a minimum diameter F100-0 staged to a F100-0 staged to an F7, for maximum altitude. What could a similar rocket do, using Estes F15 black powder motors, and it turns out, Estes E16 black powder motors?
I wanted to start with a realistic design, not a motor with a nose cone on from of the motor, but an actual workable rocket design. From initial RASAero II flight simulation runs, it became quickly apparent that the rocket would have to be a multi-stage rocket. There are of course Estes F15-0 and E16-0 booster motors available.
For a realistic upper stage, I used Adrian Adamson's Aerotech F10 rocket, the flight of which was described in this thread:
https://www.rocketryforum.com/threads/taking-a-shot-at-the-g-record.176171/
Adrian's rocket for the F10 flight, inputted into the RASAero II software, is shown below.
The boattail is removed, and the motor is extended down 1.0 inches to slide into the top of the booster, and that is the upper stage.
Of course it seems odd to use such advanced construction techniques as Adrian used for the rocket, and then use Estes black powder motors to power it. But to exceed Mach 1 and/or exceed 10,000 ft altitude above the launch site, weight will be critical. Adrian's rocket is a built and flown rocket, very light-weight, with very thin fins. The upper stage would carry Adrian's Featherweight instrumentation package, just like the original F10 version of the rocket did.
Adrian's F10 rocket launch weight was 0.36 lbs, you subtract out the Aerotech F10 motor weight, and the rocket empty weight (no motor) is 0.177 lbs. Then you add the Estes black powder motor upper stage for the initial weight.
For the boosters, I assumed that the booster empty (no motor) weight was one quarter of the upper stage weight, one quarter of 0.177 lbs, or 0.044 lbs.
As recommended by others, I used an Estes E16 for the first stage, as it was recommended that the Estes F15 would be a little low on initial thrust for a multi-stage rocket. When you compare the thrust curves at thrustcurve.org, the Estes F15 doesn't have appreciably lower thrust during the initial part of the motor burn, it does have lower thrust during the "sustain" portion of the black powder "boost-sustain" thrust curve. But additionally, the Estes F15 does weigh 18 grams more than the Estes E16; this all adds up to the Estes E16 being best for Stage-1.
The rocket configuration is shown below, the RASAero II .CDX1 rocket file is also attached. It was assumed that the rocket would be tower launched, and Black Rock launch site conditions were used for the RASAero II flight simulation. Note that you'll have to add the Estes E16 and F15 thrust curves from the thrustcurve.org website to the RASAero II rasp.eng file, see Pages 93-97 in the RASAero II Users Manual for editing the rasp.eng file or reading data from additional rasp.eng files. The rocket is a three-stage rocket. The straight fins on Stage-1 and Stage-2 are for tumble recovery of the stages after separation from the next stage up. Only the fins on Stage-3 need to be swept, the Mach numbers are low enough on Stage-1 and Stage-2 that straight (unswept) fins can be used.
The results? For an E16-0 staged to an F15-0 staged to an F15-8, you can't quite get past Mach 1.0, the maximum Mach number is Mach 0.95. You also can't quite get over 10,000 ft. The altitude in the flight simulation at apogee is just over 10,000 ft, but the F15-8 ejection charge will go off 17.01 seconds after lift-off. At time = 17.01 sec the altitude is 9,129 ft, the velocity is 271 ft/sec, so perhaps a streamer could be used and the high risk that a "zipper" will occur could be accepted. But still, using Estes model rocket black powder motors, Mach 0.95 and 9,129 ft altitude is very impressive.
For an F15-0 staged to an F15-0 staged to an F15-8, the maximum Mach number is Mach 0.97, and when the F15-8 ejection charge goes off at time = 18.37 sec, the altitude is 9,807 ft. The .CDX1 file for this flight is attached below. There is a similar "zipper problem" as the velocity when the F15-8 ejection charge goes off is 277 ft/sec. As others have noted, this flight could require a long launch tower as an F15-0 is used for Stage-1.
As I'm busy doing analysis projects and writing projects, I won't be building this rocket. But I think this rocket or a similar rocket would be a really neat rocket to build and fly, an Estes black powder model rocket that would reach almost Mach 1 and almost 10,000 ft in altitude.
Charles E. (Chuck) Rogers
Inspired by lr64's 'is it possible to go supersonic on an Estes black powder motor' thread:
https://www.rocketryforum.com/threa...rsonic-on-an-estes-motor.186994/#post-2598528
And Flight Systems Incorporated (FSI) minimum diameter F100 and F7 rockets I built and flew when I was 16-18 years old;
I've asked the following question. Is it possible to go supersonic (exceed Mach 1) using Estes black powder motors? A corollary question is; is it possible to exceed 10,000 ft using Estes black powder motors?
When I was 16-18 years old, I'd fly minimum diameter multi-stage FSI F100 and F7 motors. A photo of one is below, including a young yours truly. The photo is from something like 1975-1977. The rocket is a minimum diameter F100-0 staged to a F100-0 staged to an F7, for maximum altitude. What could a similar rocket do, using Estes F15 black powder motors, and it turns out, Estes E16 black powder motors?
I wanted to start with a realistic design, not a motor with a nose cone on from of the motor, but an actual workable rocket design. From initial RASAero II flight simulation runs, it became quickly apparent that the rocket would have to be a multi-stage rocket. There are of course Estes F15-0 and E16-0 booster motors available.
For a realistic upper stage, I used Adrian Adamson's Aerotech F10 rocket, the flight of which was described in this thread:
https://www.rocketryforum.com/threads/taking-a-shot-at-the-g-record.176171/
Adrian's rocket for the F10 flight, inputted into the RASAero II software, is shown below.
The boattail is removed, and the motor is extended down 1.0 inches to slide into the top of the booster, and that is the upper stage.
Of course it seems odd to use such advanced construction techniques as Adrian used for the rocket, and then use Estes black powder motors to power it. But to exceed Mach 1 and/or exceed 10,000 ft altitude above the launch site, weight will be critical. Adrian's rocket is a built and flown rocket, very light-weight, with very thin fins. The upper stage would carry Adrian's Featherweight instrumentation package, just like the original F10 version of the rocket did.
Adrian's F10 rocket launch weight was 0.36 lbs, you subtract out the Aerotech F10 motor weight, and the rocket empty weight (no motor) is 0.177 lbs. Then you add the Estes black powder motor upper stage for the initial weight.
For the boosters, I assumed that the booster empty (no motor) weight was one quarter of the upper stage weight, one quarter of 0.177 lbs, or 0.044 lbs.
As recommended by others, I used an Estes E16 for the first stage, as it was recommended that the Estes F15 would be a little low on initial thrust for a multi-stage rocket. When you compare the thrust curves at thrustcurve.org, the Estes F15 doesn't have appreciably lower thrust during the initial part of the motor burn, it does have lower thrust during the "sustain" portion of the black powder "boost-sustain" thrust curve. But additionally, the Estes F15 does weigh 18 grams more than the Estes E16; this all adds up to the Estes E16 being best for Stage-1.
The rocket configuration is shown below, the RASAero II .CDX1 rocket file is also attached. It was assumed that the rocket would be tower launched, and Black Rock launch site conditions were used for the RASAero II flight simulation. Note that you'll have to add the Estes E16 and F15 thrust curves from the thrustcurve.org website to the RASAero II rasp.eng file, see Pages 93-97 in the RASAero II Users Manual for editing the rasp.eng file or reading data from additional rasp.eng files. The rocket is a three-stage rocket. The straight fins on Stage-1 and Stage-2 are for tumble recovery of the stages after separation from the next stage up. Only the fins on Stage-3 need to be swept, the Mach numbers are low enough on Stage-1 and Stage-2 that straight (unswept) fins can be used.
The results? For an E16-0 staged to an F15-0 staged to an F15-8, you can't quite get past Mach 1.0, the maximum Mach number is Mach 0.95. You also can't quite get over 10,000 ft. The altitude in the flight simulation at apogee is just over 10,000 ft, but the F15-8 ejection charge will go off 17.01 seconds after lift-off. At time = 17.01 sec the altitude is 9,129 ft, the velocity is 271 ft/sec, so perhaps a streamer could be used and the high risk that a "zipper" will occur could be accepted. But still, using Estes model rocket black powder motors, Mach 0.95 and 9,129 ft altitude is very impressive.
For an F15-0 staged to an F15-0 staged to an F15-8, the maximum Mach number is Mach 0.97, and when the F15-8 ejection charge goes off at time = 18.37 sec, the altitude is 9,807 ft. The .CDX1 file for this flight is attached below. There is a similar "zipper problem" as the velocity when the F15-8 ejection charge goes off is 277 ft/sec. As others have noted, this flight could require a long launch tower as an F15-0 is used for Stage-1.
As I'm busy doing analysis projects and writing projects, I won't be building this rocket. But I think this rocket or a similar rocket would be a really neat rocket to build and fly, an Estes black powder model rocket that would reach almost Mach 1 and almost 10,000 ft in altitude.
Charles E. (Chuck) Rogers
Attachments
Last edited:
