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Post by srbrant on Nov 21, 2017 4:27:15 GMT
Now I know for a fact that this is going to get shot down, but please hear me out.
This is a possible way to increase velocity and RM efficiency. A miniature particle accelerator built between the fuel pump and the engine core that, like a coilgun, accelerates a minute portion of reaction mass until it is fired out the back end at three - perhaps even five - times the velocity. To prevent these pups from reaching relativistic speeds, their dry mass is increased until the Delta-V is at around 3-6.00.
I know there's going to be a lot of shit being pointed out in this idea, but I want to see what the issues with it are and how I can seal them up with properly applied phlebetonium - enough so that the entire engine design isn't handwaved so I can prevent my SF from getting too soft.
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Post by The Astronomer on Nov 21, 2017 5:06:38 GMT
Isn't that essentially an ion engine?
Also, if you're talking about combustion remasses, they're probably useless if the speed's greater than their detonation velocity.
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Post by srbrant on Nov 21, 2017 5:22:26 GMT
Isn't that essentially an ion engine? Also, if you're talking about combustion remasses, they're probably useless if the speed's greater than their detonation velocity. Combustion? Too wimpy. And you may be right, but I don't want porridge-slow acceleration.
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Post by RiftandRend on Nov 21, 2017 5:25:30 GMT
What are you actually describing here? A neutral particle accelerator can be used as an engine on its own but I don't see the point in accelerating remass into the engine core. The tiny portion of the remass you are accelerating would simply run into the rest of the non accelerated propellent, achieving nothing.
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Post by Enderminion on Nov 21, 2017 14:50:53 GMT
so Ev is based on the average speed of the components, and ratios and other BS. increasing the speed of some Re-mass will increase the average Ev, but unless its like 20-30% of all the re mass then the difference is not gonna be worth the powerplant and radiators
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Post by srbrant on Nov 21, 2017 17:22:05 GMT
so Ev is based on the average speed of the components, and ratios and other BS. increasing the speed of some Re-mass will increase the average Ev, but unless its like 20-30% of all the re mass then the difference is not gonna be worth the powerplant and radiators Oh? Please explain.
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Post by Enderminion on Nov 21, 2017 17:44:14 GMT
Ummm, I am not a rocket scientist, I don't know the specifics
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Post by Kerr on Nov 21, 2017 18:09:44 GMT
Using an particle accelerator won't be a practical mean of accelerating fuel, have you seen the LHC? That thing barely produces micronewtons and weight thousands of tons, extreme propulsion optimization could bring this a few magnitudes down but you still won't have "interesting" propulsion. Instead of using the accelerator to add high exhaust remass into the exhaust stream you could use it or something else to heat up fuel in the core. That would be useful all the way up to nuclear gas core designs. If you have something like fusion the accelerator could be used to initiate fusion reactions. I think you are trying to have innovative ideas in the wrong place, increasing "remass efficiency" can't be done without having to invest something, mass/energy and momentum are conserved in our reality, there is no way around this. But science provides a lot of options of having good fuel efficiency. Nuclear can be very good for within solar systems, even in stories if you have gas core nuclear thermal engines. Fusion is key to torchships, although not without adding remass such as tungsten to get high accelerations.
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Post by srbrant on Nov 21, 2017 18:59:00 GMT
Using an particle accelerator won't be a practical mean of accelerating fuel, have you seen the LHC? That thing barely produces micronewtons and weight thousands of tons, extreme propulsion optimization could bring this a few magnitudes down but you still won't have "interesting" propulsion. Instead of using the accelerator to add high exhaust remass into the exhaust stream you could use it or something else to heat up fuel in the core. That would be useful all the way up to nuclear gas core designs. If you have something like fusion the accelerator could be used to initiate fusion reactions. I think you are trying to have innovative ideas in the wrong place, increasing "remass efficiency" can't be done without having to invest something, mass/energy and momentum are conserved in our reality, there is no way around this. But science provides a lot of options of having good fuel efficiency. Nuclear can be very good for within solar systems, even in stories if you have gas core nuclear thermal engines. Fusion is key to torchships, although not without adding remass such as tungsten to get high accelerations. Fusion power is incredibly commonplace in my story, so that's a yes. But how to make such a high-efficiency system without turning the ship into an 890Kt death machine?
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Post by Kerr on Nov 21, 2017 19:36:30 GMT
Using an particle accelerator won't be a practical mean of accelerating fuel, have you seen the LHC? That thing barely produces micronewtons and weight thousands of tons, extreme propulsion optimization could bring this a few magnitudes down but you still won't have "interesting" propulsion. Instead of using the accelerator to add high exhaust remass into the exhaust stream you could use it or something else to heat up fuel in the core. That would be useful all the way up to nuclear gas core designs. If you have something like fusion the accelerator could be used to initiate fusion reactions. I think you are trying to have innovative ideas in the wrong place, increasing "remass efficiency" can't be done without having to invest something, mass/energy and momentum are conserved in our reality, there is no way around this. But science provides a lot of options of having good fuel efficiency. Nuclear can be very good for within solar systems, even in stories if you have gas core nuclear thermal engines. Fusion is key to torchships, although not without adding remass such as tungsten to get high accelerations. Fusion power is incredibly commonplace in my story, so that's a yes. But how to make such a high-efficiency system without turning the ship into an 890Kt death machine? Why not make it a 890kT Death Machine? How did you got that number? An fusion engine will consist out of 3 structural parts, The blade shield, the support structure and ships bottom cone. The cone and shield are 200:1 Angled pieces of material which reflect 99% X-rays and 99% Neutrons out into space. Achieving heat efficiencies of +99.9%. The bottom cone is has to be long and thin to achieve that 200:1 Ratio, so your entire ship might consist out of a bicone with a ring mounted on the end. The ignition system is a major thing to choose from. Your best bets are Z-pinch and ICF for high thrust. The latter can utilize shell fusion which I covered with matterbeam on the future tech thread (page. 36) Achieving exhaust velocities in the realm of megameters per second and extreme accelerations. Often only limited by what your crew might survive, you can also trade thrust for delta-v by not using shells while in flight. 560km/s 5G for combat and 8Mm/s 0.3G for cruising. If you want further information just ask.
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Post by treptoplax on Nov 21, 2017 21:45:10 GMT
Now I know for a fact that this is going to get shot down, but please hear me out. This is a possible way to increase velocity and RM efficiency. A miniature particle accelerator built between the fuel pump and the engine core that, like a coilgun, accelerates a minute portion of reaction mass until it is fired out the back end at three - perhaps even five - times the velocity. To prevent these pups from reaching relativistic speeds, their dry mass is increased until the Delta-V is at around 3-6.00. I know there's going to be a lot of shit being pointed out in this idea, but I want to see what the issues with it are and how I can seal them up with properly applied phlebetonium - enough so that the entire engine design isn't handwaved so I can prevent my SF from getting too soft. Besides engineering there's a physics issue. Engine thrust is (propellent mass) x (exhaust velocity) Engine power is (propellent mass) x .5 x (exhaust velocity) x (exhaust velocity) If you have 3x exhaust velocity (and thus 3x deltaV) the same thrust will require 9x as much power. 5x dV is 25x power at same thrust. Not impossible but there's going to be a lot of waste heat one way or another.
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Post by srbrant on Nov 22, 2017 2:21:47 GMT
Now I know for a fact that this is going to get shot down, but please hear me out. This is a possible way to increase velocity and RM efficiency. A miniature particle accelerator built between the fuel pump and the engine core that, like a coilgun, accelerates a minute portion of reaction mass until it is fired out the back end at three - perhaps even five - times the velocity. To prevent these pups from reaching relativistic speeds, their dry mass is increased until the Delta-V is at around 3-6.00. I know there's going to be a lot of shit being pointed out in this idea, but I want to see what the issues with it are and how I can seal them up with properly applied phlebetonium - enough so that the entire engine design isn't handwaved so I can prevent my SF from getting too soft. Besides engineering there's a physics issue. Engine thrust is (propellent mass) x (exhaust velocity) Engine power is (propellent mass) x .5 x (exhaust velocity) x (exhaust velocity) If you have 3x exhaust velocity (and thus 3x deltaV) the same thrust will require 9x as much power. 5x dV is 25x power at same thrust. Not impossible but there's going to be a lot of waste heat one way or another. Thank the Omnissiah for fusion reactors... ...And the huge heat-sails in my story.
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Post by The Astronomer on Nov 22, 2017 2:25:35 GMT
Besides engineering there's a physics issue. Engine thrust is (propellent mass) x (exhaust velocity) Engine power is (propellent mass) x .5 x (exhaust velocity) x (exhaust velocity) If you have 3x exhaust velocity (and thus 3x deltaV) the same thrust will require 9x as much power. 5x dV is 25x power at same thrust. Not impossible but there's going to be a lot of waste heat one way or another. Thank the Omnissiah for fusion reactors... ...And the huge heat-sails in my story. The thing is, just use the damn fusion rockets you fik
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Post by srbrant on Nov 22, 2017 2:31:59 GMT
Thank the Omnissiah for fusion reactors... ...And the huge heat-sails in my story. The thing is, just use the damn fusion rockets you fik Okay, okay.
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Post by The Astronomer on Nov 22, 2017 2:40:29 GMT
The thing is, just use the damn fusion rockets you fik Okay, okay. Oh, and if you want more thrust you can always add in some remass
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