Well that does suck and SW does not come cheap nor ANSYS. RAS for Cd is better than nothing, I suppose. If you were to pull this off in time for flight by the end of this year I think the best launch event would be BALLS seeing as they have had 300kft+ waivers and that would save a lot of time and headaches with trying to get your own wavier. That of course would require you to break your relationship with AeroPac launches but if everything else works out for you then this might be the best option to actually get it in the air.
I just read the ISC part of your write up and it appears your ISC design is to primarily minimize overall length of the vehicle. However I do think that to add ~3-6" to the overall length at the cost of saving thousands of dollars is a game changer. You can use the sustainer motor as the stack coupler and you will not gain much space over your current design as a result. Yes you will have some new design hurdles (stability one of them) but nothing to hard to design around. Any altitude losses due to this change would be "up in the air," with your predicted forecasts. Also if you want lightweight ( as you previously mentioned) go with composites for the material selection of the ISC, it can be done. On that note your sustainer fins do not need to be Ti and your booster fins are over designed being 0.157" thick plus the 10 layers (5 on each side) of tip-to-tip. My point? I think you have trade offs that you can do to save money, decrease time, and keep altitude to approximately the same but YOU will have to work harder with the changes.
Hmm, I was unaware of AHPRA's waiver standings, but I will look into them. This may prove useful indeed if they already have the ceiling, but per RocksimPro Monte Carlo distribution results (which I have asked for a few times from a friend and have yet to receive, Ill ask again today) I may very well need a cylinder expansion perhaps up to 20 miles instead of 10. TRA Class3 committee can most likely aid me in the logistics of that, I think. Not sure how easy it might be, though, given as Jim had stated, Black Rock is huge but not THAT huge. 20 miles puts Gerlach and Empire on the edge of the fall zone. No bueno. Ill have a look into it for sure.
Okay I think everyone who is trying to tell me to use the motor as a coupler is not fully understanding what Im trying to say- Yes, guys, I realize that using tongues is extremely expensive. BUT IT HAS BEEN DONE FOR CHEAP BEFORE. There ARE ways to design it to be very similar to what I have, and per the result of the step DMLS quote if I can get that in the next few days, I will be right back here on AutoCAD redrawing and redrawing and redrawing untill I find a shape that satisfies and is easy enough to produce. Again, it has been done before very similar to my design.
I really do NOT want to use the motor as a coupler. It wouldnt be a hard stability workaround, it would be a nearly IMPOSSIBLE stability workaround given the M2245's fast burn.
DOING SO DRASTICALLY SHIFTS CP FORWARD RELATIVE TO CG RANGE. This dramatically reduces stability unless fin size is increased. WITH FIN SIZE INCREASE comes lowered divergence and flutter velocitieis. Thus requiring STRONGER or thicker materials, aka more expensive, unless I were to use straight up steel, which is very heavy, and Im honestly not even sure if I could make that stay stable realistically. With using the motor as a coupler into the IST instead of using any sort of tongues, you basically let the motor hang 6 to 8 to 10 inches behind the fins. No. Bueno.
The M2245 simply pushes the sustainer TOO FAST for this to be a viable design method.
For the sake of discussion, if I were to do this method, I wouldnt even need a fincan sleeve. I could theoretically use carbon fins and t-t, bonded to airframe and friction fit those suckers on and hope they didnt come sliding off the back in flight. Why not do this? Carbon wouldnt survive the speed, and the vehicle wouldnt be stable at the speed. I would be forced to use a longburn motor. aka shorter motor with less impulse, go slower, and a lot lower. Aka, a whole new project essentially.
Why use .15 cores with 5 layers of bagged t-t for my booster? Because per simulation, that sucker is going to be doing upwards of mach 2.5 at the top of the boost, around 8,000ft MSL. This is a lot of aerodynamic stress on a 4 inch diameter's fins. Note how many 98mm rockets shredded from poor fin construction at these exact same conditions in the past. Overbuilt is under built in the case of a vehicle designed to go this fast. I am confident that this will suffice for booster tail construction.
Food for thought - my original Dragonplate quote came back at $600 for STANDARD 0/90 plate fins with a diamond airfoil added to them by Dragonplate. Needless to say, I will just be having them do quasi-isotropic cores and I will add the beveling myself on a 3 axis mill. It's really easy with a 5 degree jig you can cut on a table saw in 15 seconds.
Balls may also offer a larger radius than 10 miles. Here are a few thoughts on the approval process (your mileage may vary) ....
If I took this project for Tripoli approval at Balls, I would expect it to be rejected at some altitude point. I don't know if that altitude would be 150K, 200K or 250K, but it would happen somewhere within that range. That's the reason that I'm working on a stabilization approach - to get approval for a flight like this (plus it's a fun project!). If you took the project for approval at Balls, your chances of approval would be significantly lower than mine.
If I took this project for Tripoli approval at a different launch with a 10-mile radius, and we assume 200K, I would expect the flight to be rejected. The odds of landing outside of 10 miles are much higher than within 10 miles. My 118K project was pretty straight and I still landed 9 miles out. There is a slight chance that with stabilization, a flight could be approved, but I would expect to have to show proof of effectiveness and a very sound plan. If you took the project for approval (200K with 10 miles), your chances of approval would be zero.
I don't speak for Tripoli on this subject, but I'm sure they will do what's necessary to protect the venue. If there is another irresponsible flight there, we will likely lose access, and then we can all make plans to visit Bob's unambiguous splash zone at some Govt. facility.
Jim
Why would everyone agree that automated trajectory control is mandatory? Lets take a look at all the rockets that busted the waiver. What did they all have in common? Lack of tiltometers to stop them from staging at 5-10D off-vertical. Where did they apogee? At the edge or beyond the waiver.
Jim, where did FourCarbYen apogee in terms of distance to the edge of the waiver? Damn near the center, right? Am I mistaken to conclude that lateral distance was accumulated primarily during DESCENT, where said trajectory control devices would have no effect anyway?
Again, I am waiting on RSpro Monte Carlo distribution results from someone who has it, or my friend that I had asked a while ago, but I wouldnt doubt TRA will require more than a standard 10 mile waiver. This being said, I wouldnt go so far as to say theyre going to put a stop to my flight without the addition of trajectory control devices, given Im atleast flying a device which will actuate or inhibit staging based on trajectory at staging.
I just cant support the concept that it is necessary to add several inches and several pounds to the rocket to do something that it shouldn't need, if allowed to stage only at the proper angle. I can forsee tumbling once the air density gets close to nil, but i cannot forsee any sort of lateral distance gain as a result of this tumbling. The ONLY thing I can see making a difference here is whether or not I allow my sustainer to light when it is already beginning a gravity turn. The stability control devices you were mentioning would for sure make a difference up to this point, but after staging, it matters more the overall trajectory angle of flight, not the angle of attack. I could see how your canard project could indeed fix overall trajectory angle (provided enough atmo to be effective), but spin stabilization would only help to hold a fixed angle of attack... (right?)
This may sound like an elementary question, but is there a way to force OR to add a tilt angle to my sustainer upon ignition, for the sake of simulating lateral distance accumulation from there on? Perhaps as the result of a gust... I can tell you that OpenRocket predicts a ground hit over 45 miles away when launched starting 10 degrees from vertical on the ground. 25 miles when at 5 degrees, and 3 miles when at a perfect 0 degrees. We can assume with the use of levels that the launch rail can be made a perfect 0, but none of us can forecast exactly what the sustainer will do when it comes time to light the motor. The only thing we CAN do is establish what should be an ACCEPTABLE deviance from vertical, and install that as a gate to sustainer ignition in the telemega, OR install trajectory control devices which add space and weight to the rocket..... I hope you can see where Im trying to go with this.
So lets get down and dirty with it. How can we take a more in depth look at sustainer ignition angles and their results on lateral distance? How do we then factor this in to Monte Carlo distribution results to produce a reasonably accurate landing range?