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![]() (This has got to qualify for geek question of the week) In the Book "Valkyire - North American's Mach 3 Superbomber" it says in regard to the AIM-47 that the original motor the XM59 would have been able to accelerate the missile to Mach 6 but the one actually used the XSR13-LP-1 could only get it to Mach 4. In Chapter 3 footnote 86 it gives you credit for chasing down the designation for the XSR13-LP-1. My question is do you by chance know what kind of fuel the XSR13-LP-1 used and what kind the XM59 used that would give it such a large increase in performance? Thanks. |
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D. Scott Ferrin wrote:
(This has got to qualify for geek question of the week) In the Book "Valkyire - North American's Mach 3 Superbomber" it says in regard to the AIM-47 that the original motor the XM59 would have been able to accelerate the missile to Mach 6 but the one actually used the XSR13-LP-1 could only get it to Mach 4. In Chapter 3 footnote 86 it gives you credit for chasing down the designation for the XSR13-LP-1. My question is do you by chance know what kind of fuel the XSR13-LP-1 used and what kind the XM59 used that would give it such a large increase in performance? Thanks. NASA has some PDF B-70 documents on its NTRS webserver: B-70 Aircraft Study - Final Report - Vol. 1 - April 1972 Data location matrix, Work breakdown structure, Cost data definitions, B-70 program summary costs. http://ntrs.nasa.gov/archive/nasa/ca...1995102358.pdf B-70 Aircraft Study - Final Report - Vol. 2 - April 1972 Air vehicle, program technical spoort, major airframe mating, flight test, flight test ground support equipment, spares, special test equipment, tooling, other program elements. http://ntrs.nasa.gov/archive/nasa/ca...1995102359.pdf B-70 Aircraft Study - Final Report - Vol. 3 - April 1972 Airframe structures, environmental control, propulsion, secondary power. http://ntrs.nasa.gov/archive/nasa/ca...1995102360.pdf B-70 Aircraft Study - Final Report - Vol. 4 - April 1972 Air induction system, flight control, personnel accommodation and escape, alighting and arresting, mission and traffic control, flight indication, test instrumentation, installation, checkout & pre-flight. http://ntrs.nasa.gov/archive/nasa/ca...1995102361.pdf A summary of XB-70 sonic boom signature data - April 1992 http://ntrs.nasa.gov/archive/nasa/ca...1992015557.pdf Wind-tunnel/flight correlation study of aerodynamic characteristics of a large flexible supersonic cruise airplane (XB-70-1) http://ntrs.nasa.gov/archive/nasa/ca...1980009724.pdf SUMMARY OF PRELIMINARY DATA DERIVED FROM THE XB-70 AIRPLANES - June 1966 http://ntrs.nasa.gov/archive/nasa/ca...1966018723.pdf ANALYSIS OF AN EMERGENCY DECELERATION AND DESCENT OF THE XB-70-1 AIRPLANE DUE TO ENGINE DAMAGE RESULTING FROM STRUCTURAL FAILURE - March 1966 http://ntrs.nasa.gov/archive/nasa/ca...1966011810.pdf Rusty |
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D. Scott Ferrin wrote:
(This has got to qualify for geek question of the week) In the Book "Valkyire - North American's Mach 3 Superbomber" it says in regard to the AIM-47 that the original motor the XM59 would have been able to accelerate the missile to Mach 6 but the one actually used the XSR13-LP-1 could only get it to Mach 4. In Chapter 3 footnote 86 it gives you credit for chasing down the designation for the XSR13-LP-1. I got creditted? Woo! I forgot I'd helped 'em with that. My question is do you by chance know what kind of fuel the XSR13-LP-1 used and what kind the XM59 used that would give it such a large increase in performance? Not anymore, no. The reference I had available to me at that time is available to me no longer (from the library of a company I no longer work for). As for what would increase the performance... could have been propellant formulation, could also have been grain geometry. If you redesign the grain, but keep the propellant the same, you can boost thrust, at expense of duration. |
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On Wed, 06 Apr 2005 23:45:31 GMT, Scott Lowther
wrote: D. Scott Ferrin wrote: (This has got to qualify for geek question of the week) In the Book "Valkyire - North American's Mach 3 Superbomber" it says in regard to the AIM-47 that the original motor the XM59 would have been able to accelerate the missile to Mach 6 but the one actually used the XSR13-LP-1 could only get it to Mach 4. In Chapter 3 footnote 86 it gives you credit for chasing down the designation for the XSR13-LP-1. I got creditted? Woo! I forgot I'd helped 'em with that. My question is do you by chance know what kind of fuel the XSR13-LP-1 used and what kind the XM59 used that would give it such a large increase in performance? Not anymore, no. The reference I had available to me at that time is available to me no longer (from the library of a company I no longer work for). As for what would increase the performance... could have been propellant formulation, could also have been grain geometry. If you redesign the grain, but keep the propellant the same, you can boost thrust, at expense of duration. The way it reads it sounds like it was the propellant formulation which was why I was wondering about it. |
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D. Scott Ferrin wrote:
On Wed, 06 Apr 2005 23:45:31 GMT, Scott Lowther wrote: D. Scott Ferrin wrote: (This has got to qualify for geek question of the week) In the Book "Valkyire - North American's Mach 3 Superbomber" it says in regard to the AIM-47 that the original motor the XM59 would have been able to accelerate the missile to Mach 6 but the one actually used the XSR13-LP-1 could only get it to Mach 4. In Chapter 3 footnote 86 it gives you credit for chasing down the designation for the XSR13-LP-1. I got creditted? Woo! I forgot I'd helped 'em with that. My question is do you by chance know what kind of fuel the XSR13-LP-1 used and what kind the XM59 used that would give it such a large increase in performance? Not anymore, no. The reference I had available to me at that time is available to me no longer (from the library of a company I no longer work for). As for what would increase the performance... could have been propellant formulation, could also have been grain geometry. If you redesign the grain, but keep the propellant the same, you can boost thrust, at expense of duration. The way it reads it sounds like it was the propellant formulation which was why I was wondering about it. Well, that being the late '50's, early '60's, there were a hell of a lot of developments in solid propellants. The specifics were, of course, generally classified, and not a lot tend to get published about 'em. Your standard propellants burn at 0.25-0.5 inches per second at aroudn a thousand psi (shuttle standard is 0.368); but they foudn ways to really jack up burn rate. Sprint proellant got to 11 inches a second, and HiBEX to around 20; these were bat-outta-Hell motors. Fastest I've heard of was over 50 inches per second burn rate, and that was jsut before the test motor blew itself to hell and gone. Burn rate is to first order NOT a function of grain geometry, but of pressure and formulation. |
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![]() Well, that being the late '50's, early '60's, there were a hell of a lot of developments in solid propellants. The specifics were, of course, generally classified, and not a lot tend to get published about 'em. Your standard propellants burn at 0.25-0.5 inches per second at aroudn a thousand psi (shuttle standard is 0.368); but they foudn ways to really jack up burn rate. Sprint proellant got to 11 inches a second, and HiBEX to around 20; these were bat-outta-Hell motors. Fastest I've heard of was over 50 inches per second burn rate, and that was jsut before the test motor blew itself to hell and gone. Burn rate is to first order NOT a function of grain geometry, but of pressure and formulation. It's the formulation that I'm curious about. I always wondered how they burned all the propellant in the 1st stage of Sprint so fast. The only drawing I've seen of the grain had a lot of area burning at once but still to smoke it all in a second and a half. . . I know burn rate and ISP don't necessarily go hand in hand and I wonder how the fuel Sprint and HIBEX compared to something like NH4ClO4/AL/HTPB. I've got Sutton's Rocket Propulsion Elements, 7th Edition and various publications dealing with making propellant in high powered rocketry but I get the feeling that the REALLY interesting stuff is proprietary information at various companies. |
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D. Scott Ferrin wrote:
Well, that being the late '50's, early '60's, there were a hell of a lot of developments in solid propellants. The specifics were, of course, generally classified, and not a lot tend to get published about 'em. Your standard propellants burn at 0.25-0.5 inches per second at aroudn a thousand psi (shuttle standard is 0.368); but they foudn ways to really jack up burn rate. Sprint proellant got to 11 inches a second, and HiBEX to around 20; these were bat-outta-Hell motors. Fastest I've heard of was over 50 inches per second burn rate, and that was jsut before the test motor blew itself to hell and gone. Burn rate is to first order NOT a function of grain geometry, but of pressure and formulation. It's the formulation that I'm curious about. I always wondered how they burned all the propellant in the 1st stage of Sprint so fast. The only drawing I've seen of the grain had a lot of area burning at once but still to smoke it all in a second and a half. . . I know burn rate and ISP don't necessarily go hand in hand and I wonder how the fuel Sprint and HIBEX compared to something like NH4ClO4/AL/HTPB. I've got Sutton's Rocket Propulsion Elements, 7th Edition and various publications dealing with making propellant in high powered rocketry but I get the feeling that the REALLY interesting stuff is proprietary information at various companies. When I worked at UTC in San Jose, one of the chemists was an old rocketeer who worked on Sprint. Most propelalnts are mixed and poured. Sprint propellant was *built*. It was a double-base propellant composed of nitrocellulose and nitroglycerin, which is common enough, but it also had some interesting additives. The most important were the staples. The propellant was built within the motor; usign early manufacturing robotics; a robot woudl reach in, and lay down a layer of powered fuel; andother robot woudl then reach in and lay down a layer of staples. Stories differed (meanign different test motor configurations)... in some, the staples were zirconium strips, in others (and, I believe, the production motors), the staples were 3-d bent aluminum staples (descriebd to me as looking precisely liek a regular staple, but with one leg bent so that all three axes were represented). In any case, after the staples, the first robot woudlr each in again, and lay down another layer of powder, and the process woudl repeat. After all the propellant was in, nitroglycerin was carefully poured in; it woudl filter through the powder, dissolve the nitrocellulose, and the staples woudl stay pretty much in place. There were assuredly other additives as well. The purpose of the staples was to speed up heat conduction through the propellant. Propellant burns at a faster rate if the bulk propellant temperature is higher... a rocket burns noticabel faster on a summer day than winter, frex. But the burn rate of most propellants is about as fast, or faster than, the speed of thermal conduction through the propellant... so even though it's 4000 degrees just a fraction of an inch off the surface, just a fraction of an inch below the surface, it's a warm day. But the staples mean the interior of the propellant heat up at the thermal conduction speed of the metal, not the proepllant. Done right, it's damendd near a barely-controlled explosion. Sometimes, not so controlled... |
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On Fri, 08 Apr 2005 01:55:15 GMT, Scott Lowther
wrote: D. Scott Ferrin wrote: Well, that being the late '50's, early '60's, there were a hell of a lot of developments in solid propellants. The specifics were, of course, generally classified, and not a lot tend to get published about 'em. Your standard propellants burn at 0.25-0.5 inches per second at aroudn a thousand psi (shuttle standard is 0.368); but they foudn ways to really jack up burn rate. Sprint proellant got to 11 inches a second, and HiBEX to around 20; these were bat-outta-Hell motors. Fastest I've heard of was over 50 inches per second burn rate, and that was jsut before the test motor blew itself to hell and gone. Burn rate is to first order NOT a function of grain geometry, but of pressure and formulation. It's the formulation that I'm curious about. I always wondered how they burned all the propellant in the 1st stage of Sprint so fast. The only drawing I've seen of the grain had a lot of area burning at once but still to smoke it all in a second and a half. . . I know burn rate and ISP don't necessarily go hand in hand and I wonder how the fuel Sprint and HIBEX compared to something like NH4ClO4/AL/HTPB. I've got Sutton's Rocket Propulsion Elements, 7th Edition and various publications dealing with making propellant in high powered rocketry but I get the feeling that the REALLY interesting stuff is proprietary information at various companies. When I worked at UTC in San Jose, one of the chemists was an old rocketeer who worked on Sprint. Most propelalnts are mixed and poured. Sprint propellant was *built*. It was a double-base propellant composed of nitrocellulose and nitroglycerin, which is common enough, but it also had some interesting additives. The most important were the staples. The propellant was built within the motor; usign early manufacturing robotics; a robot woudl reach in, and lay down a layer of powered fuel; andother robot woudl then reach in and lay down a layer of staples. Stories differed (meanign different test motor configurations)... in some, the staples were zirconium strips, in others (and, I believe, the production motors), the staples were 3-d bent aluminum staples (descriebd to me as looking precisely liek a regular staple, but with one leg bent so that all three axes were represented). In any case, after the staples, the first robot woudlr each in again, and lay down another layer of powder, and the process woudl repeat. After all the propellant was in, nitroglycerin was carefully poured in; it woudl filter through the powder, dissolve the nitrocellulose, and the staples woudl stay pretty much in place. There were assuredly other additives as well. The purpose of the staples was to speed up heat conduction through the propellant. Propellant burns at a faster rate if the bulk propellant temperature is higher... a rocket burns noticabel faster on a summer day than winter, frex. But the burn rate of most propellants is about as fast, or faster than, the speed of thermal conduction through the propellant... so even though it's 4000 degrees just a fraction of an inch off the surface, just a fraction of an inch below the surface, it's a warm day. But the staples mean the interior of the propellant heat up at the thermal conduction speed of the metal, not the proepllant. Done right, it's damendd near a barely-controlled explosion. Sometimes, not so controlled... Yeah that book I mentioned above talks about wires and staples to increase the burn rate too and it mentioned several metals including aluminum, silver, and zirconium. It left me wondering if it were just the conduction of the heat into the unburned propellent that increased the burn rate or if the burning surface was able to travel along the staple/propellent interface into the propellent with the net effect being a somewhat increased surface area burning. |
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D. Scott Ferrin wrote:
Yeah that book I mentioned above talks about wires and staples to increase the burn rate too and it mentioned several metals including aluminum, silver, and zirconium. It left me wondering if it were just the conduction of the heat into the unburned propellent that increased the burn rate or if the burning surface was able to travel along the staple/propellent interface into the propellent with the net effect being a somewhat increased surface area burning. That is almost certainly an effect as well. Plus, zirconium goes absolutely ape in the presense of a hot oxidizer. |
#10
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Scott Lowther wrote:
zirconium goes absolutely ape [..] You know, between this ("absolutely ape") and Mary's "sticky-outy bit" s.s.h. has become a treasure-trove of new technical terminology to me. ;-) |
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