Brewing Master

Question:

As mentioned, biggest problem is the inability to control the thrust level (although Boeing had developed its own version of a throttlable solid for one of the military space programs).  This can manifest itself in more than just the inability to shoot touch and goes…You’d really like to optimize the burn rate for the phase of flight.  A good burst at the start for takeoff, and a longer, lower-thrust, sustainer burn.  Easy to design, but a custom pour’ll undoubtedly cost more. Ron "Easier to mount on an Arizona Oldsmobile, too" Wanttaja

A true Me163 Komet would not be able to do T and Gs due to a lack of wheels. I was thinking of a spectacular take off followed by a few glide by passes and a landing. This would not require a sustain phase so I assume a monopropellent should work. That part is above my pay grade. I don’t recall whether the origonal Komet had a throttle. On the subject of throttles how in the Hell would one throttle a solid? Dan, U. S. Air Force, retired

Response:

For repeated, public, flights, I’d probably lean towards solid rockets.  Probably take an explosives license to handle them, but that shouldn’t be that big of a problem.  Excellent thrust, good reliability.   As mentioned, biggest problem is the inability to control the thrust level (although Boeing had developed its own version of a throttlable solid for one of the military space programs).  This can manifest itself in more than just the inability to shoot touch and goes…You’d really like to optimize the burn rate for the phase of flight.  A good burst at the start for takeoff, and a longer, lower-thrust, sustainer burn.  Easy to design, but a custom pour’ll undoubtedly cost more. Ron "Easier to mount on an Arizona Oldsmobile, too" Wanttaja

Shame on you for not knowing your Urban Legends Ron.  EVERYONE knows that it was a Chevy Impala in the cliff in Arizona. http://www.snopes.com/autos/dream/jato.htm http://www.darwinawards.com/darwin/darwin1995-04.html http://www.wagoneers.com/pages/RocketCar/AZ-state-on-the-myth.html http://www1.bored.com/rocketcar/page4.htm http://www.delta-9.com/net47/myth/impala.html http://www.tiac.net/users/cri/darwin95.html http://wueconb.wustl.edu/~ec110ev/fa99/darwin.html http://www.skyhawk.org/darw96.htm http://www.drunkbastard.net/regularhumor/azdarwin.htm http://yarchive.net/car/rocket_car.html http://www.humournet.com/collage.archives/collage080.txt http://www.sandpoint.com/off_the_cuff/jato.htm http://www.porkpie.demon.co.uk/jatostor.htm http://www.gimmick.nl/us/dea6.htm http://www.geocities.com/mikey_wbt/urban_legends/jato_car.html http://www.f-16.net/library/stories/jato.html – John Ousterhout –

Response:

LOX and diesel fuel… Available everywhere…  Cheap…  No EPA problems with the exhaust…  You will need an igniter in the combustion chamber to keep it lit, but that’s only details… H2O2 engine, like Dick Rutan has been flying recently…  Exhaust is water and steam… Keeps your whites whiter…  Ultra high concentration H2O2 is expensive, I suspect….  Not readily available everywhere.. RFNA and alcohol, or JP-4, or Gasoline, or UDMH…  Lots more expensive and the EPA gonna get you…  Especially for the RFNA and UDMH… Denny – Hide quoted text — Show quoted text – No, hypergolic is any combination of fuel and oxidizer that spontaneously ignites when brought together.  Like White Fuming Nitric Acid (WFNA) and turpentine or furfuryl alcohol.  A fuel that caries it’s own oxidizer is a monopropellant, like ethelene oxide or nitromethane.  They tend to go BOOM at the worst possible moment.  But they make for much simpler fuel systems.  The only one used is hydrazine, but it’s a toxic as toxic can be.  It’s only used for control thrusters, not for main propulsion. Depends on what one defines as "main propulsion."  Worked on systems which used monoprop for the orbit-adjust engines.  Bipropellant or solid upper stages for insertion, of course. Monoprop systems are lighter and simpler, but have a lower specific impulse (layman’s translation:  "Oooooompppphhh") than biprops.  The crossover point in a System Mass (including propellant) vs. Delta-V Capability plot helps the designer pick out which system to use for his vehicle. For an airshow Komet, any liquid fuel system is going to be on the verge of being too awkward.  You’ve either got to transport large amounts of toxic propellants or arrange delivery of liquid oxygen to the flight line.  A hydrazine spill on the flight line at Oshkosh. Brrrr…. For repeated, public, flights, I’d probably lean towards solid rockets.  Probably take an explosives license to handle them, but that shouldn’t be that big of a problem.  Excellent thrust, good reliability.   As mentioned, biggest problem is the inability to control the thrust level (although Boeing had developed its own version of a throttlable solid for one of the military space programs).  This can manifest itself in more than just the inability to shoot touch and goes…You’d really like to optimize the burn rate for the phase of flight.  A good burst at the start for takeoff, and a longer, lower-thrust, sustainer burn.  Easy to design, but a custom pour’ll undoubtedly cost more. Ron "Easier to mount on an Arizona Oldsmobile, too" Wanttaja

Response:

The best would probably be N20 and Kerosene.  Cheap, self pressurizing, virtually un-regulated, and it makes a crowd pleasing exhaust.  The only bad thing is that is ISP is a little low, but that hardly matters in this case. -Aaron – Hide quoted text — Show quoted text – LOX and diesel fuel… Available everywhere…  Cheap…  No EPA problems with the exhaust…  You will need an igniter in the combustion chamber to keep it lit, but that’s only details… H2O2 engine, like Dick Rutan has been flying recently…  Exhaust is water and steam… Keeps your whites whiter…  Ultra high concentration H2O2 is expensive, I suspect….  Not readily available everywhere.. RFNA and alcohol, or JP-4, or Gasoline, or UDMH…  Lots more expensive and the EPA gonna get you…  Especially for the RFNA and UDMH… Denny No, hypergolic is any combination of fuel and oxidizer that spontaneously ignites when brought together.  Like White Fuming Nitric Acid (WFNA) and turpentine or furfuryl alcohol.  A fuel that caries it’s own oxidizer is a monopropellant, like ethelene oxide or nitromethane.  They tend to go BOOM at the worst possible moment.  But they make for much simpler fuel systems.  The only one used is hydrazine, but it’s a toxic as toxic can be.  It’s only used for control thrusters, not for main propulsion. Depends on what one defines as "main propulsion."  Worked on systems which used monoprop for the orbit-adjust engines.  Bipropellant or solid upper stages for insertion, of course. Monoprop systems are lighter and simpler, but have a lower specific impulse (layman’s translation:  "Oooooompppphhh") than biprops.  The crossover point in a System Mass (including propellant) vs. Delta-V Capability plot helps the designer pick out which system to use for his vehicle. For an airshow Komet, any liquid fuel system is going to be on the verge of being too awkward.  You’ve either got to transport large amounts of toxic propellants or arrange delivery of liquid oxygen to the flight line.  A hydrazine spill on the flight line at Oshkosh. Brrrr…. For repeated, public, flights, I’d probably lean towards solid rockets.  Probably take an explosives license to handle them, but that shouldn’t be that big of a problem.  Excellent thrust, good reliability. As mentioned, biggest problem is the inability to control the thrust level (although Boeing had developed its own version of a throttlable solid for one of the military space programs).  This can manifest itself in more than just the inability to shoot touch and goes…You’d really like to optimize the burn rate for the phase of flight.  A good burst at the start for takeoff, and a longer, lower-thrust, sustainer burn.  Easy to design, but a custom pour’ll undoubtedly cost more. Ron "Easier to mount on an Arizona Oldsmobile, too" Wanttaja

Response:

LOX and diesel fuel… Available everywhere…  Cheap…  No EPA problems with the exhaust…  You will need an igniter in the combustion chamber to keep it lit, but that’s only details… H2O2 engine, like Dick Rutan has been flying recently…  Exhaust is water and steam… Keeps your whites whiter…  Ultra high concentration H2O2 is expensive, I suspect….  Not readily available everywhere..

The rocket engine Dick Rutan has been flying recently runs on isopropyl alcohol and liquid oxygen (I watched him fly it last November). It’s fitted in a Long-Ez (two 400lb thrust engines) and the igniter is…well, essentially a weedwhacker spark plug with electronic ignition. — Dylan Smith, Houston, TX Flying: http://www.dylansmith.net Frontier Elite Universe: http://www.alioth.net "Maintain thine airspeed, lest the ground come up and smite thee"

Response:

Ron "Easier to mount on an Arizona Oldsmobile, too" Wanttaja Shame on you for not knowing your Urban Legends Ron.  EVERYONE knows that it was a Chevy Impala in the cliff in Arizona.

Yeah, but *I* drive an Oldsmobile… Ron Wanttaja

Response:

What kind of impulse would you get from Nitrous Oxide and Cellulose, like the model rocket hybrids?  Throttlable, easy to handlle oxidizer (thought the tanks weigh as much as their content), widely available and relatively innexpensive.  The fuel could be shredded compressed newspaper.

ISP on such a rig?  Beats the heck outta me.  In the words of the immortal Donald Sutherland: "I only drive them…I don’t know what makes them work." [the ball is in your court, Nauga! ] Back when I used to do this sort of thing for a living, I just picked a fuel from a table.  I *didn’t* shred the table and try to use it for propellant. LOX and diesel fuel… Available everywhere…  Cheap…  No EPA problems with the exhaust…  You will need an igniter in the combustion chamber to keep it lit, but that’s only details…

I didn’t consider cryogenic fuels because I suspect the logistics would be a bit of a hassle…small lots, getting an industrial company’s supply truck to support a time-critical application, safety hazard with a supercooled exterior, etc.  There’s a lot to be said for an aircraft that you can just stick a hose in and dump fuel into… A true Me163 Komet would not be able to do T and Gs due to a lack of wheels.

How ’bout a teeny caster imbedded in the skid? I was thinking of a spectacular take off followed by a few glide by passes and a landing. This would not require a sustain phase so I assume a monopropellent should work. That part is above my pay grade.

Your mission plan matched my thoughts, with perhaps a roll or knife-edge pass or two.   The fun is to see it flying, not in judging its acrobatic prowess.  Think Delmar Benjamin and the Gee Bee replica. Here’s a lot more "doable" option:   The unpowered Dutch replica was launched with an auto-tow.  Use a twin Beech or similar to haul your airshow replica aloft.  Loiter at altitude until show time, then have the Komet release and go through its routine.  Put a propane burner or something inside the fuselage to provide the appropriate noise, flame, and smoke trail. Doesn’t have to provide thrust. Or you might carry water ballast to improve penetration and just spray some out on each pass. After all, you’re probably going to want to have the Komet air-towable anyway, for practice flying and to transport it between airshows. Without the need to carry fuel, the airplane can be designed for a lot lower gross weight.  It turns into a fairly low-tech machine…. There’s a neat scene for a CAF airshow… a Komet scooting across the field with a pair of Mustangs on its tail…. On the subject of throttles how in the Hell would one throttle a solid?

Can’t quite remember how that one program did it, but it was something like adding a big shutter to the exhaust nozzle.  Close off the nozzle and the internal pressure rises, reducing the rate of burn.  Someone else mentioned an approach where oxidizer or propellant was injected into the solid. Ron Wanttaja

Response:

Might be possible but with a solid fuel rocket there can be no throttle control.  It is either burning or it isn’t.

That is true of conventional solids, but not of an advanced hybrid developed quite a few years ago (Thiokol?) in which a liquid component, the flow of which was controllable, reacted with the solid propellant to generate the hot gas.         – David Fisher

Response:

Perhaps with something like a RATO engine?  I’m sure most folks here have seen the Blue Angels’ "Fat Albert" C-130 do it.  Quite impressive.

Response:

Perhaps with something like a RATO engine?  I’m sure most folks here have seen the Blue Angels’ "Fat Albert" C-130 do it.  Quite impressive.

Perhaps, but still devoid of controllability. Not to worry; it’s all idle talk, anyway.         – David Fisher

Response:

Not to worry; it’s all idle talk, anyway.    - David Fisher

You never know Dan, U. S. Air Force, retired

Response:

Take a look at http://www.xcor-aerospace.com/me163.html.  It’s not solid fuel, but they’ve demoed the liquid engines in a Long EZ. – Hide quoted text — Show quoted text – Might be possible but with a solid fuel rocket there can be no throttle control.  It is either burning or it isn’t. That is true of conventional solids, but not of an advanced hybrid developed quite a few years ago (Thiokol?) in which a liquid component, the flow of which was controllable, reacted with the solid propellant to generate the hot gas.    - David Fisher

Response:

Take a look at http://www.xcor-aerospace.com/me163.html.  It’s not solid fuel, but they’ve demoed the liquid engines in a Long EZ.

I’ve got some photos/video from the Xcor unveiling of the Rocket-Ez on my website – http://www.dylansmith.net/flying/trips/xcor if anyone’s interested. — Dylan Smith, Houston, TX Flying: http://www.dylansmith.net Frontier Elite Universe: http://www.alioth.net "Maintain thine airspeed, lest the ground come up and smite thee"

Response:

Take a look at http://www.xcor-aerospace.com/me163.html.  It’s not solid fuel, but they’ve demoed the liquid engines in a Long EZ.

That rocket used liquid fuels and it was not hypergolic as stated on the web page. Unless they plan on using a hypergolic fuel in the replica. Hypergolic refers to fuel that contains at least part of its own oxidizer. They used Liquid Hydrogen Peroxide which is highly unstable and alcohol in the original. — Roger (K8RI EN73) WWW.RogerHalstead.com N833R, World’s Oldest Debonair? S#CD-2

– Hide quoted text — Show quoted text – Might be possible but with a solid fuel rocket there can be no throttle control.  It is either burning or it isn’t. That is true of conventional solids, but not of an advanced hybrid developed quite a few years ago (Thiokol?) in which a liquid component, the flow of which was controllable, reacted with the solid propellant to generate the hot gas. – David Fisher

Response:

I’m gonna go warm up the Impalla…   I’ll bet I could do at least 165mph with one of them thingies strapped onta the trunk…

Response:

I expect, though, that the BATF requirements might be a bit onerous. Ron Wanttaja

BATF??? Jim in NC

Response:

Bureau of Alcohol, Tobacco and Firearms

Response:

Take a look at http://www.xcor-aerospace.com/me163.html.  It’s not solid fuel, but they’ve demoed the liquid engines in a Long EZ. That rocket used liquid fuels and it was not hypergolic as stated on the web page. Unless they plan on using a hypergolic fuel in the replica. Hypergolic refers to fuel that contains at least part of its own oxidizer. They used Liquid Hydrogen Peroxide which is highly unstable and alcohol in the original.

No, hypergolic refers to propellants, which, when mixed, require no external ignition source — they ignite spontaneously. RFNA/UDMH is an example.

Response:

:

: Take a look at http://www.xcor-aerospace.com/me163.html.  It’s not : solid fuel, but they’ve demoed the liquid engines in a Long EZ. : :That rocket used liquid fuels and it was not hypergolic as stated on the web :page. Unless they plan on using a hypergolic fuel in the replica. I wouldn’t think of hypergolic fuel as necessarily a goal.  Lots of rockets aren’t hypergolic – the V2 (LOX-Alcohol) or the Space Shuttle Main Engine (LOX-LH2).  Or the F1 engine off the Saturn 5 (Kerosene-LOX).  For that matter, any of the engines on the Apollo. : :Hypergolic refers to fuel that contains at least part of its own oxidizer. No, hypergolic is any combination of fuel and oxidizer that spontaneously ignites when brought together.  Like White Fuming Nitric Acid (WFNA) and turpentine or furfuryl alcohol.  A fuel that caries it’s own oxidizer is a monopropellant, like ethelene oxide or nitromethane.  They tend to go BOOM at the worst possible moment.  But they make for much simpler fuel systems.  The only one used is hydrazine, but it’s a toxic as toxic can be.  It’s only used for control thrusters, not for main propulsion. : :They used Liquid Hydrogen Peroxide which is highly unstable and alcohol in :the original. Yep,  An acquaintance of mine, Frederich Dingler, flew them.  He was once talking about how the various other pilots died.  I asked how he survived, he said "once they got down to the last couple of us they gave much gave up."   High test H2O2 can be used, there were a bunch of H2O2 rocket dragsters a few years ago.  But you don’t want to spill it, almost anything will catalyze it.  Then it liberates massive amounts of O2 and heat, and just about anything in the area will catch fire and burn nicely.  People included.

Response:

High test H2O2 can be used, there were a bunch of H2O2 rocket dragsters a few years ago.  But you don’t want to spill it, almost anything will catalyze it.  Then it liberates massive amounts of O2 and heat, and just about anything in the area will catch fire and burn nicely.  People included.

That’s why I suggested solid fuel. ATF may have a licensing thing about it , but such things are legal. I am not suggesting flying the thing cross country. That would require a throttleable rocket. I would consider doing the research on a solid rocket engine just for giggles and I may yet do so. The dimensions of a Sidewinder engine look about right at first glance. As for flying it, well, aside from fear of heights, inability to pass the medical, being too big to fit in it……. hell yeah, wotta way to go!! Dan, U. S. Air Force, retired

Response:

No, hypergolic is any combination of fuel and oxidizer that spontaneously ignites when brought together.  Like White Fuming Nitric Acid (WFNA) and turpentine or furfuryl alcohol.  A fuel that caries it’s own oxidizer is a monopropellant, like ethelene oxide or nitromethane.  They tend to go BOOM at the worst possible moment.  But they make for much simpler fuel systems.  The only one used is hydrazine, but it’s a toxic as toxic can be.  It’s only used for control thrusters, not for main propulsion.

Depends on what one defines as "main propulsion."  Worked on systems which used monoprop for the orbit-adjust engines.  Bipropellant or solid upper stages for insertion, of course. Monoprop systems are lighter and simpler, but have a lower specific impulse (layman’s translation:  "Oooooompppphhh") than biprops.  The crossover point in a System Mass (including propellant) vs. Delta-V Capability plot helps the designer pick out which system to use for his vehicle. For an airshow Komet, any liquid fuel system is going to be on the verge of being too awkward.  You’ve either got to transport large amounts of toxic propellants or arrange delivery of liquid oxygen to the flight line.  A hydrazine spill on the flight line at Oshkosh. Brrrr…. For repeated, public, flights, I’d probably lean towards solid rockets.  Probably take an explosives license to handle them, but that shouldn’t be that big of a problem.  Excellent thrust, good reliability.   As mentioned, biggest problem is the inability to control the thrust level (although Boeing had developed its own version of a throttlable solid for one of the military space programs).  This can manifest itself in more than just the inability to shoot touch and goes…You’d really like to optimize the burn rate for the phase of flight.  A good burst at the start for takeoff, and a longer, lower-thrust, sustainer burn.  Easy to design, but a custom pour’ll undoubtedly cost more. Ron "Easier to mount on an Arizona Oldsmobile, too" Wanttaja

Response:

What kind of impulse would you get from Nitrous Oxide and Cellulose, like the model rocket hybrids?  Throttlable, easy to handlle oxidizer (thought the tanks weigh as much as their content), widely available and relatively innexpensive.  The fuel could be shredded compressed newspaper. : :No, hypergolic is any combination of fuel and oxidizer that :spontaneously ignites when brought together.  Like White Fuming Nitric :Acid (WFNA) and turpentine or furfuryl alcohol.  A fuel that caries :it’s own oxidizer is a monopropellant, like ethelene oxide or :nitromethane.  They tend to go BOOM at the worst possible moment.  But :they make for much simpler fuel systems.  The only one used is :hydrazine, but it’s a toxic as toxic can be.  It’s only used for :control thrusters, not for main propulsion. : epends on what one defines as "main propulsion."  Worked on systems :which used monoprop for the orbit-adjust engines.  Bipropellant or :solid upper stages for insertion, of course. : :Monoprop systems are lighter and simpler, but have a lower specific :impulse (layman’s translation:  "Oooooompppphhh") than biprops.  The :crossover point in a System Mass (including propellant) vs. Delta-V :Capability plot helps the designer pick out which system to use for :his vehicle. : :For an airshow Komet, any liquid fuel system is going to be on the :verge of being too awkward.  You’ve either got to transport large :amounts of toxic propellants or arrange delivery of liquid oxygen to :the flight line.  A hydrazine spill on the flight line at Oshkosh. :Brrrr…. : :For repeated, public, flights, I’d probably lean towards solid :rockets.  Probably take an explosives license to handle them, but that :shouldn’t be that big of a problem.  Excellent thrust, good :reliability.   : :As mentioned, biggest problem is the inability to control the thrust :level (although Boeing had developed its own version of a throttlable :solid for one of the military space programs).  This can manifest :itself in more than just the inability to shoot touch and goes…You’d :really like to optimize the burn rate for the phase of flight.  A good :burst at the start for takeoff, and a longer, lower-thrust, sustainer :burn.  Easy to design, but a custom pour’ll undoubtedly cost more. : :Ron "Easier to mount on an Arizona Oldsmobile, too" Wanttaja

Response:

It occured to me awhile ago that one could make a composite Me163 that uses off the shelf solid fuel rocket engines. I am sure such rockets are are either already available of one could have them made. I am not saying they would be cheap, but imagine the effect at an airshow. I recall seeing a car trying for land speed record using a Sidewinder engine for boost. I assume the aircraft would be sufficiently lighter than the origonal that much less thrust would be required. Refueling would be easier, just slide the expended engine out and replace, and a whole lot safer that T stoff and C stoff. Dan, U. S Air Force, retired

Response:

It occured to me awhile ago that one could make a composite Me163 that uses off the shelf solid fuel rocket engines. I am sure such rockets are are either already available of one could have them made. I am not saying they would be cheap, but imagine the effect at an airshow. I recall seeing a car trying for land speed record using a Sidewinder engine for boost. I assume the aircraft would be sufficiently lighter than the origonal that much less thrust would be required. Refueling would be easier, just slide the expended engine out and replace, and a whole lot safer that T stoff and C stoff.

Well, we at least know it’s possible to build a gliding replica of the Komet… http://www.sml.lr.tudelft.nl/%7Ehome/rob/me163/kurz.htm Would be interesting, all right.  Depending upon the energy management, one could probably give a pretty good show after a rocket takeoff. I expect, though, that the BATF requirements might be a bit onerous. Ron Wanttaja

Response:

Might be possible but with a solid fuel rocket there can be no throttle control.  It is either burning or it isn’t.  The car he mentioned if anyone is interested was driven at Edwards, sponsered by Bud and actually broke the sound barrier first on land.  It was driven by Stan Barrett and the car now is the International Motorsports Hall of Fame in Talladega, AL   It wasn’t given the land speed record because apparently there are rules set by the FIA that the car didnt meet. — Mark Blackwell http://www.aviatorsonestop.com

– Hide quoted text — Show quoted text – It occured to me awhile ago that one could make a composite Me163 that uses off the shelf solid fuel rocket engines. I am sure such rockets are are either already available of one could have them made. I am not saying they would be cheap, but imagine the effect at an airshow. I recall seeing a car trying for land speed record using a Sidewinder engine for boost. I assume the aircraft would be sufficiently lighter than the origonal that much less thrust would be required. Refueling would be easier, just slide the expended engine out and replace, and a whole lot safer that T stoff and C stoff. Well, we at least know it’s possible to build a gliding replica of the Komet… http://www.sml.lr.tudelft.nl/%7Ehome/rob/me163/kurz.htm Would be interesting, all right.  Depending upon the energy management, one could probably give a pretty good show after a rocket takeoff. I expect, though, that the BATF requirements might be a bit onerous. Ron Wanttaja

Response: