PmWiki.RamAccelerator History
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August 30, 2017, at 12:40 AM
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The vehicle is effectively "pinched" forward. Ram accelerator pioneer Carl Knowlen likens the mechanism to pinching a watermelon seed to make it fly -- the slimy surface of the seed reduces the frictional forces against thumb and fingertip; the seed speeds away much faster than the fingertips come together. A ram accelerator's internal detonation waves supply the "pinch". This means a vehicle can be accelerated to a velocity much greater than than the velocity of the detonation waves that strike the boat tail.[^Except for for implosion-tube concepts, other gas-based projectile launch schemes have a speed limit related to the limit of the speed of sound in the gases used for propulsion.^]
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The vehicle is effectively "pinched" forward. Ram accelerator pioneer Carl Knowlen likens the mechanism to pinching a watermelon seed to make it fly -- the slimy surface of the seed reduces the frictional forces against thumb and fingertip; the seed speeds away much faster than the fingertips come together. A ram accelerator's internal detonation waves supply the "pinch". This means a vehicle can be accelerated to a velocity much greater than than the velocity of the detonation waves that strike the boat tail.[^Except for implosion-tube concepts, other gas-based projectile launch schemes have a speed limit related to the limit of the speed of sound in the gases used for propulsion.^]
August 30, 2017, at 12:39 AM
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!! Further reading
Extensive online bibliography on the RAMAC here: "[[https://link.springer.com/chapter/10.1007%2F978-3-319-26018-1_4 | The Ram Accelerator: Review of Experimental Research Activities in the U.S.]]", A Bruckner, C Knowlen, in ''[[https://link.springer.com/book/10.1007/978-3-319-26018-1 | Hypervelocity Launchers]]'', Friedrich Seiler, Ozer Igra, eds., Springer pp. 79-109. ISBN 978-3-319-26016-7 (print), 978-3-319-26018-1 (ebook). https://doi.org/10.1007/978-3-319-26018-1
!! Further reading
Extensive online bibliography on the RAMAC here: "[[https://link.springer.com/chapter/10.1007%2F978-3-319-26018-1_4 | The Ram Accelerator: Review of Experimental Research Activities in the U.S.]]", A Bruckner, C Knowlen, in ''[[https://link.springer.com/book/10.1007/978-3-319-26018-1 | Hypervelocity Launchers]]'', Friedrich Seiler, Ozer Igra, eds., Springer pp. 79-109. ISBN 978-3-319-26016-7 (print), 978-3-319-26018-1 (ebook). https://doi.org/10.1007/978-3-319-26018-1
March 10, 2017, at 12:53 AM
by - yet more rewrite
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The ram accelerator (sometimes, "ram cannon") is a [[projectile space launch]] concept based on exploiting the ramjet concept in a tube, and with detonation waves rather than mere combusion. Instead of reacting against a nozzle, the expanding gases react against a "boat tail", effectively turning the nozzle idea inside-out.
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The ram accelerator (sometimes, "ram cannon") is a [[projectile space launch]] concept based on exploiting the scramjet concept in a tube.[^"Gasdynamic Operation of Baffled Tube Ram Accelerator in Highly Energetic Mixtures", A.J. Higgins, C. Knowlen, C.B. Kiyanda, Submitted to: 20th International Colloquium on the Dynamics of Explosions and Reactive Systems. http://www.galcit.caltech.edu/~jeshep/icders/cd-rom/EXTABS/178_20TH.PDF^] Instead of reacting against a nozzle, the expanding gases react against a "boat tail", effectively turning the nozzle idea inside-out. In a scramjet engine, the oxidizer (oxygen) is in the atmosphere, the air it scoops up as the vehicle flies forward; the fuel is carried onboard. In a ram accelerator, the fuel isn't carried; both the fuel and the oxidizer are in the tube. The vehicle's fuel+oxidizer supply is always ahead of it, at least for the very short time it's in the tube.[^It's carrying fuel and oxidizer that make rockets to space so big and multi-staged.^]
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The vehicle is effectively "pinched" forward. Ram accelerator pioneer Carl Knowlen likens the mechanism to pinching a watermelon seed to make it fly -- the slimy surface of the seed means the seed escapes the frictional forces against thumb and fingertip; the seed speeds away much faster than the fingertips come together. A ram accelerator's internal detonation waves supply the "pinch". This means a vehicle can be accelerated to a velocity much greater than than the velocity of the detonation waves that strike the boat tail. [^"Gasdynamic Operation of Baffled Tube Ram Accelerator in Highly Energetic Mixtures", A.J. Higgins, C. Knowlen, C.B. Kiyanda, Submitted to: 20th International Colloquium on the Dynamics of Explosions and Reactive Systems. http://www.galcit.caltech.edu/~jeshep/icders/cd-rom/EXTABS/178_20TH.PDF^]
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The vehicle is effectively "pinched" forward. Ram accelerator pioneer Carl Knowlen likens the mechanism to pinching a watermelon seed to make it fly -- the slimy surface of the seed reduces the frictional forces against thumb and fingertip; the seed speeds away much faster than the fingertips come together. A ram accelerator's internal detonation waves supply the "pinch". This means a vehicle can be accelerated to a velocity much greater than than the velocity of the detonation waves that strike the boat tail.[^Except for for implosion-tube concepts, other gas-based projectile launch schemes have a speed limit related to the limit of the speed of sound in the gases used for propulsion.^]
March 10, 2017, at 12:38 AM
by - better illustration
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The ram accelerator (sometimes, "ram cannon") is a [[projectile space launch]] concept based on exploiting the ramjet concept in a tube, and with detonation waves rather than mere combusion. Instead of reacting against a nozzle, the expanding gases react against a "boat tail", effectively turning the nozzle idea inside-out. The vehicle is effectively "pinched" forward. Ram accelerator pioneer Carl Knowlen likens the mechanism to pinching a watermelon seed to make it fly -- the slimy surface of the seed means the seed escapes the frictional forces against thumb and fingertip; the seed speeds away much faster than the fingertips come together. A ram accelerator's internal detonation waves supply the "pinch". This means a vehicle can be accelerated to a velocity much greater than than the velocity of the detonation waves that strike the boat tail. [^"Gasdynamic Operation of Baffled Tube Ram Accelerator in Highly Energetic Mixtures", A.J. Higgins, C. Knowlen, C.B. Kiyanda, Submitted to: 20th International Colloquium on the Dynamics of Explosions and Reactive Systems. http://www.galcit.caltech.edu/~jeshep/icders/cd-rom/EXTABS/178_20TH.PDF^]
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The ram accelerator (sometimes, "ram cannon") is a [[projectile space launch]] concept based on exploiting the ramjet concept in a tube, and with detonation waves rather than mere combusion. Instead of reacting against a nozzle, the expanding gases react against a "boat tail", effectively turning the nozzle idea inside-out.
http://www.ramaccelerator.org/home/sites/default/files/wiley%20scramjet-scra.PNG
The vehicle is effectively "pinched" forward. Ram accelerator pioneer Carl Knowlen likens the mechanism to pinching a watermelon seed to make it fly -- the slimy surface of the seed means the seed escapes the frictional forces against thumb and fingertip; the seed speeds away much faster than the fingertips come together. A ram accelerator's internal detonation waves supply the "pinch". This means a vehicle can be accelerated to a velocity much greater than than the velocity of the detonation waves that strike the boat tail. [^"Gasdynamic Operation of Baffled Tube Ram Accelerator in Highly Energetic Mixtures", A.J. Higgins, C. Knowlen, C.B. Kiyanda, Submitted to: 20th International Colloquium on the Dynamics of Explosions and Reactive Systems. http://www.galcit.caltech.edu/~jeshep/icders/cd-rom/EXTABS/178_20TH.PDF^]
http://www.ramaccelerator.org/home/sites/default/files/wiley%20scramjet-scra.PNG
The vehicle is effectively "pinched" forward. Ram accelerator pioneer Carl Knowlen likens the mechanism to pinching a watermelon seed to make it fly -- the slimy surface of the seed means the seed escapes the frictional forces against thumb and fingertip; the seed speeds away much faster than the fingertips come together. A ram accelerator's internal detonation waves supply the "pinch". This means a vehicle can be accelerated to a velocity much greater than than the velocity of the detonation waves that strike the boat tail. [^"Gasdynamic Operation of Baffled Tube Ram Accelerator in Highly Energetic Mixtures", A.J. Higgins, C. Knowlen, C.B. Kiyanda, Submitted to: 20th International Colloquium on the Dynamics of Explosions and Reactive Systems. http://www.galcit.caltech.edu/~jeshep/icders/cd-rom/EXTABS/178_20TH.PDF^]
March 10, 2017, at 12:37 AM
by - rewording
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The ram accelerator (sometimes, "ram cannon") is a [[projectile space launch]] concept based on exploiting the ramjet concept in a tube, and with detonation waves rather than mere combusion. Rather than reacting against a nozzle, the gases react against a "boat tail", effectively turning the nozzle idea inside-out. The vehicle is effectively "pinched" forward. Ram accelerator pioneer Carl Knowlen likens the mechanism to pinching a watermelon seed -- the slimy surface of the seed means the seed escaped the frictional forces against thumb and fingertip; the seed speeds away much faster than the fingertips coming together. This means a ram accelerator vehicle can be accelerated to a velocity much greater than than the velocity of the detonation waves that strike the boat tail. [^"Gasdynamic Operation of Baffled Tube Ram Accelerator in Highly Energetic Mixtures", A.J. Higgins, C. Knowlen, C.B. Kiyanda, Submitted to: 20th International Colloquium on the Dynamics of Explosions and Reactive Systems. http://www.galcit.caltech.edu/~jeshep/icders/cd-rom/EXTABS/178_20TH.PDF^]
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The ram accelerator (sometimes, "ram cannon") is a [[projectile space launch]] concept based on exploiting the ramjet concept in a tube, and with detonation waves rather than mere combusion. Instead of reacting against a nozzle, the expanding gases react against a "boat tail", effectively turning the nozzle idea inside-out. The vehicle is effectively "pinched" forward. Ram accelerator pioneer Carl Knowlen likens the mechanism to pinching a watermelon seed to make it fly -- the slimy surface of the seed means the seed escapes the frictional forces against thumb and fingertip; the seed speeds away much faster than the fingertips come together. A ram accelerator's internal detonation waves supply the "pinch". This means a vehicle can be accelerated to a velocity much greater than than the velocity of the detonation waves that strike the boat tail. [^"Gasdynamic Operation of Baffled Tube Ram Accelerator in Highly Energetic Mixtures", A.J. Higgins, C. Knowlen, C.B. Kiyanda, Submitted to: 20th International Colloquium on the Dynamics of Explosions and Reactive Systems. http://www.galcit.caltech.edu/~jeshep/icders/cd-rom/EXTABS/178_20TH.PDF^]
March 10, 2017, at 12:22 AM
by - expanded description
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The ram accelerator (sometimes, "ram cannon") is a [[projectile space launch]] concept based on exploiting the ramjet concept in a tube, around the vehicle rather than inside it.[^"Gasdynamic Operation of Baffled Tube Ram Accelerator in Highly Energetic Mixtures", A.J. Higgins, C. Knowlen, C.B. Kiyanda, Submitted to: 20th International Colloquium on the Dynamics of Explosions and Reactive Systems. http://www.galcit.caltech.edu/~jeshep/icders/cd-rom/EXTABS/178_20TH.PDF^]
to:
The ram accelerator (sometimes, "ram cannon") is a [[projectile space launch]] concept based on exploiting the ramjet concept in a tube, and with detonation waves rather than mere combusion. Rather than reacting against a nozzle, the gases react against a "boat tail", effectively turning the nozzle idea inside-out. The vehicle is effectively "pinched" forward. Ram accelerator pioneer Carl Knowlen likens the mechanism to pinching a watermelon seed -- the slimy surface of the seed means the seed escaped the frictional forces against thumb and fingertip; the seed speeds away much faster than the fingertips coming together. This means a ram accelerator vehicle can be accelerated to a velocity much greater than than the velocity of the detonation waves that strike the boat tail. [^"Gasdynamic Operation of Baffled Tube Ram Accelerator in Highly Energetic Mixtures", A.J. Higgins, C. Knowlen, C.B. Kiyanda, Submitted to: 20th International Colloquium on the Dynamics of Explosions and Reactive Systems. http://www.galcit.caltech.edu/~jeshep/icders/cd-rom/EXTABS/178_20TH.PDF^]
March 10, 2017, at 12:14 AM
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%center% http://www.ramaccelerator.org/home/sites/default/files/hp-testsection-pic.jpg | [[http://ramaccelerator.org/home/node/7| The ram accelerator facility at the University of Washington]]
The ram accelerator (sometimes, "ram cannon") is a [[projectile space launch]] concept based on exploiting the ramjet concept in a tube, around the vehicle rather than inside it.[^"Gasdynamic Operation of Baffled Tube Ram Accelerator in Highly Energetic Mixtures", A.J. Higgins, C. Knowlen, C.B. Kiyanda, Submitted to: 20th International Colloquium on the Dynamics of Explosions and Reactive Systems. http://www.galcit.caltech.edu/~jeshep/icders/cd-rom/EXTABS/178_20TH.PDF^]
http://www.ramaccelerator.org/home/sites/default/files/wiley%20operation%20sequence.PNG
!! References
[^#^]
The ram accelerator (sometimes, "ram cannon") is a [[projectile space launch]] concept based on exploiting the ramjet concept in a tube, around the vehicle rather than inside it.[^"Gasdynamic Operation of Baffled Tube Ram Accelerator in Highly Energetic Mixtures", A.J. Higgins, C. Knowlen, C.B. Kiyanda, Submitted to: 20th International Colloquium on the Dynamics of Explosions and Reactive Systems. http://www.galcit.caltech.edu/~jeshep/icders/cd-rom/EXTABS/178_20TH.PDF^]
http://www.ramaccelerator.org/home/sites/default/files/wiley%20operation%20sequence.PNG
!! References
[^#^]