Differences between revisions 2 and 3
Revision 2 as of 2017-10-11 00:35:22
Size: 4341
Revision 3 as of 2017-10-11 00:41:55
Size: 4357
Deletions are marked like this. Additions are marked like this.
Line 48: Line 48:
|| Antonov 124 || 405 tonnes || 300 km/h WAG || 83 m/s || 1400 MJ ||
|| Concorde || 181 tonnes || 360 km/h || 100 m/s || 905 MJ ||
|| Antonov 124 || 405 tonnes || 300 km/h '''WAG!!!''' || 83 m/s || 1400 MJ ||
|| Concorde    || 181 tonnes || 360 km/h     || 100 m/s || 905 MJ ||

Aircraft Launch with Launch Loop Transformer Track Technology

Military Fighter Launch

  • Note: I prefer peace to war, and defense to offense. Perhaps if defense is good enough compared to offense, war becomes unlikely. But people are insane, so I fear this will just add fuel to the hellish fire of hatred. Loop power requires a well-prepared fixed location, a source of electrical power, and is unlikely to be usable in occupied territory without months of construction. I welcome suggestions to make this even less likely to be used for offensive operations.

One of the first applications of loop technology may be the rapid burst launch of squadrons of military aircraft. Presume control distributed among the aircraft to separate them safely after launch, and to control them in the turbulent wake of their predecessors, so they can average one second spacing. In peacetime, this allows low cost training and quiet operation, less likely to upset civilian neighbors. It reduces pollution and fuel consumption. Green war? :-(

I was in the economy parking lot at Portland Airport (PDX) when a pair of F15s (?) took off from runway 10L, then rotated and hit the afterburners overhead, seemingly straight up. The noise was ear-splitting and bone rattling; when the noise and shaking died down, I could hear half-a-dozen car alarms blaring in the parking lot. Pilots need training I suppose, but every noisy exercise like this shifts voters into the "cut the military budget, shut down the PDX Air Guard" voting block. A quiet way to launch training exercises, and a quick way to get an entire squadron airborne and at altitude when a threat is detected, will promote a squadron's political and military survivability.

Assume a launch of 30 F-35A aircraft, one per second. WAG follows:

  • Takeoff mass: 30 tonnes
  • Maximum takeoff engine thrust: 100 kN (added to catapult thrust)
  • Takeoff acceleration: 20 m/s²
  • Takeoff speed: 120 m/s (much faster than carrier)
    • 50 m/s² 5 gee turn, 144 meter radius, about 2 seconds to straight up
    • Afterburners above 300 meters (far above ground) to continue climb

  • Loop catapult thrust 500 kN, total 600 kN
  • Takeoff time 6 seconds (and 6 vehicles in process)
  • Takeoff length 360 m
  • Unpowered abort length 640 m (including curved "waterbath" dispersal to avoid rear-end collision)
  • Takeoff energy = 216 MJ per aircraft (including engine power)
  • Takeoff energy from loop = 180 MJ per aircract
  • Takeoff energy for 30 aircraft = 5.4 GJ = 1500 kWh from the loop (about $200 of electrical input)
  • Average power during launch 180 MW

The aircraft may be connected to the sled with cables so they can be "flown like kites" after reaching takeoff speed. They can be hauled back down to the ground during an abort, with subsequent aircraft flying over the aborted aircraft.

Wikipedia: The EMALS 300-foot (91 m) LIM will accelerate a 100,000-pound (45,000 kg) aircraft to 130 kn (240 km/h; 150 mph), cites EDN 240 km/h is 66.7 m/s, in 91m is average 24.4 m/s², perhaps a peak of 30 m/s², kinetic energy of 200 MJ.

Launch loop version 1 assumes a 14km radius D magnet and 14 km/s, thus a radial acceleration of 14000 m/s². A 500 m radius power loop with 8,000 m/s² acceleration would move at 2000 m/s and store 2 MJ/kg. 3000 meters of 4 kg/m rotor stores 24 GJ. With a transformer track, this is more than enough energy to launch the 30 aircraft. With a 1 MW grid feed, loop energy could be restored in 90 minutes.

Commercial airport runway launch

If the system is available for war, it should be maintained for peaceful purposes 95% of the time. Commercial airliners are less noisy but perform many more takeoffs around most airports. Let's protect the neighbor's ears from these as well.

Here's some air transport takeoff masses and speeds:

Boeing 737

45 tonnes

250 km/h

69 m/s

108 MJ

Boeing 757

109 tonnes

260 km/h

72 m/s

284 MJ

Boeing 747

363 tonnes

290 km/h

81 m/s

1180 MJ

Antonov 124

405 tonnes

300 km/h WAG!!!

83 m/s

1400 MJ


181 tonnes

360 km/h

100 m/s

905 MJ

AircraftLaunch (last edited 2017-10-27 19:45:18 by KeithLofstrom)