Originally posted by ContrailRockets
With a little modification the HT GSE would work with these motors.
They do NOT use the Fill Stems for HT GSE. No Kline Valve, Either.
There have been and are a number of goals for this project. We took a step back and viewed the HT Motors from an outsiders perspective. We also took all the feedback which we have received over the past 18 months regarding HT motors and tried to come up with a solution.
A lot of the complaints stemmed from those fill stems So They went.
Other complaints came from "HT motors are all low impulse, why can't they do what Contrail Motors do?!?" So we juiced them up a bit... Now they are fast
We have a pretty decent list of improvements made, and in the coming weeks I will post them.
Also Coming soon are: Videos, Thrust Curves, Prices, and More!
Hi Tom,
With all due respect, you have been making high regression/fast burn claims about your motors and fuel since they were released. I have some questions, comments and observations without prejudice and for hopefully some fun and interesting dialogue.
Why is it that none of your TMT certified motors have a delivered Isp published? There are also some inconsistencies with some of the certification data that I can see and it seems to dispute your claim of "high regression". Let's take your M-2281 for example. I'll cite directly from TMT's published data. It shows a "loaded" weight of 5579 grams and a recovery weight of 5238 grams for a delta of 341 grams. I'm not sure why that doesn't include oxidizer mass BTW and if it does, it's clearly in error (3200 cc). The motor fuel grain weight starts at 1306 grams and again, the burnout delta is 341 grams. That doesn't sound like high regression rate fuel to me. It appears like the motor running predominantly in monopropellant mode and that may be why the delivered Isp was not published. N2O has a theoretical Isp of about 170 under standard ideal conditions (1000 psi, SL expanded). If you squirt 3200 grams of N2O though 4 big injector holes as in the case of your M and exothermically decompose it over a period of 2 plus seconds, one would expect to see the thrust levels reported, combustion efficiency and delivered Isp aside. The start/finish masses as published seem to confirm some of this as well as the nozzle material used in that particular motor. From the published data, some of your motors have delivered Isp in the low 100's that we can tell.
Keep in mind that I have at least one of your motors in the lab and have also done extensive ion spectrometry on the fuel compositions. I'll be more than happy to publish the basis for my position as well as my findings if you like. Both CTI and EAC have considerable expertise and IP in the area of high regression rate fuels, both hybrid and solid. Nothing in the analysis and tests that I conducted suggest your fuel formulations or motor design meets the definition. Frankly, I take exception to some of your claims and data unless you can provide anything to substantiate them further. I've attached the HT HPR properties spreadsheet for your information and If you have anything along these lines that you can provide, it might help to clarify some of this. I'll also be happy to address your O motor failure analysis as it pertains to HTPB fuel compositions and thermal shock seeing you publicly cited HyperTek in the report. Korey and I have a lot of experience in that regard with our Hyperion class motors.
Further more, the Contrails TMT certification data states testing was done in compliance with NFPA 1125. Was the testing done on TMT's test stand or on your trailer setup? If the latter, how was the system calibrated and do you have tractability methods such as NIST employed? Was the motor and it's propellants conditioned to pre-firing temperature as per NFPA? Were N2O pressures and temperatures recorded and if so, how? In other words, how was the actual N2O mass determined. Were the fuel burn out weights recorded? Was the post firing temperature of case recorded as per NFPA? Who and how many from TMT were present and who reduced the data? TMT was quite thorough and demanding along these lines when we were certifying with them so what has changed? CAR and NAR still seem to be insisting on the details. So, good rocket science and data or has marketing and just get the stuff out there taken the lead these days?
I guess all of this is quite moot if the consumers really don't care. As I mentioned previously, much of the propulsion aspects of the sport have digressed into pyrotechnics and if that's acceptable to the participants, then I guess it's fine. In other words, who cares as long as there is the effect? Just don't look for any significant technological advances going forward. BTW, the hobby, EX and alt.space don't have any idea about what's going on in advanced hybrid technology right now.
As far as your "Trojan" design is concerned, you should review the following U.S. patents and note the independent claims, our registered trademarks notwithstanding.
5715675 Hybrid valve techniques-- The Kline Valve See Fig 1
5893266 Pyrotechnic valve ignition Pyrotechnic material blocking the flow of oxidizer. See Fig 12
6058697 Fill Techniques- Hypertek Fill Stem A tube which communicates to the injector face thru the nozzle technically includes the so called UC Valve See Fig 2
6082097 Reloadable hybrid rocket motors --Cartridge reloadable combustion chambers. See Fig 2 thru 5
6912839 Ignition techniques for hybridsHypertek Gox ignition system See Fig 1
These are primarily HPR related and there are more, jointly or solely owned by CTI and/or EAC for commercial/military applications including high regression rate fuels.
Korey and I have each spent well into the six figures developing HPR hybrids alone over the years. Korey already has left HPR for the most part and as much as I enjoy the hobby, some of my management look at me like I have two heads for being involved in HPR at all. Someone, after reading your post, reminded me that I make all those custom diameter Hypertek tanks in house. If I jump ship, I guess you or your customers will need to find a new supplier. Then again, I might wake up grumpy some morning and decide to do something about the status quo, one way or another.
Anthony J. Cesaroni
President/CEO
Cesaroni Technology/Cesaroni Aerospace
https://www.cesaronitech.com/
(941) 360-3100 x101 Sarasota
(905) 887-2370 x222 Toronto