Mostrando entradas con la etiqueta Engine. Mostrar todas las entradas
Mostrando entradas con la etiqueta Engine. Mostrar todas las entradas

miércoles, 29 de julio de 2015

NASA rocket could defy laws of physics and fly to moon in 4hrs

German scientists have confirmed that the so-called "EMDrive" rocket created by NASA could defy the known laws of physics and be capable of flying to the moon in just four hours.


While the invention doesn't create Star Trek "warp drive," it has been calculated that it could generate speeds sufficient to reach Mars in 70 days, travel beyond the Solar System in 18 months or so — it took New Horizon nine years to get to Pluto — and make a round trip to explore alien life on all of Saturn's moons in only three years.

These latest tests appear to confirm that we could be on the verge of an epoch-making leap forward in space travel — a breakthrough which might make intergalactic space exploration, encounters with alien life and colonization of distant planets a real possibility.

Originally, NASA scientists doubted the validity of their own results from the rocket tests, as the EMDrive (electromagnetic propulsion drive,) seemed to defy the laws of physics.

Back in April, NasaSpaceFlight.com reported that; "Thrust measurements of the EMDrive defy classical physics’ expectations that such a closed (microwave) cavity should be unusable for space propulsion because of the law of conservation of momentum."

However, The Mail Online explains that;

"The concept of an EmDrive engine is relatively simple. It provides thrust to a spacecraft by bouncing microwaves around in a closed container. Solar energy provides the electricity to power the microwaves, which means that no propellant is needed."

Science Alert says that the drive creates huge amounts of propulsion without the need for rocket fuel;
"Instead, it's apparently propelled forward by microwaves bouncing back and forth inside an enclosed chamber."
EMDrive rocket
Roger Sawyer
In doing so, the journal explains, "it defies one of the fundamental concepts of physics - the conservation of momentum, which states that for something to be propelled forward, some kind of propellant needs to be pushed out in the opposite direction."

For this reason, the concept was ignored or ridiculed by scientists, when it was first put forward in the early 2000s by British scientist, Roger Shawyer, and there are still many skeptics looking to find other reasons to explain why the rocket cannot be feasible.

However, Chinese scientists later built their own version, which worked. So NASA's Eagleworks Laboratories also set about testing Shawyer's rocket.

To everyone's amazement, it seemed to work, and NASA's experiments have now been confirmed by rigorous tests carried out by professor Martin Tajmar, at Dresden University of Technology in Germany, who presented his results at the 2015 American Institute for Aeronautics and Astronautics' Propulsion and Energy Forum and Exposition in Florida two days ago.

Commenting on Tajmar's experiments, Wired.com says that;
"The obvious sources of error -- air currents, leaking microwaves, ionisation -- have long ago been ruled out. But this is the first time that someone with a well-equipped lab and a strong background in tracking experimental error has been involved, rather than engineers who may be unconsciously influenced by a desire to see it work."

The problem is, however, nobody can yet explain this "impossible thrust" which is generated – something Shawyer estimated to be several thousand times greater than a normal photon rocket.

According to Hacked.com, Dr. Harold G. “Sonny” White at the Johnson Space Center (JSC) has suggested that;
"The EM Drive’s thrust is due to virtual particles in the quantum vacuum that behave like propellant ions in magneto-hydrodynamical propulsion systems, extracting "fuel" from the very fabric of space-time and eliminating the need to carry propellant."

From Tajmar's Propulsion and Energy Forum paper, 
co-authored by G. Fiedler Martin Tajmar

This would overturn some fundamental tenants of quantum physics because particles in the quantum vacuum cannot be ionised, so therefore you cannot push against it, says the Mail Online.

But as Wired.com commented;
"Some damage to our theories of physics is an acceptable payoff if we get a working space drive."

Tajmar concluded his studies by saying;
"Additional tests need to be carried out to study the magnetic interaction of the power feeding lines used for the liquid metal contacts."

"Nevertheless, we do observe thrusts close to the magnitude of the actual predictions after eliminating many possible error sources that should warrant further investigation into the phenomena."

A Romanian engineer, Berca Lulian, has also carried out similar experiments which he has published, and which tend to confirm the current findings. Indeed, the new site EmDrive Wiki lists over a dozen other projects which are currently trying to replicate the results.

Commenting on the findings, NASA officials said online that: "There are many 'absurd' theories that have become reality over the years of scientific research."

Until there is a theoretical explanation for what is happening, some skepticism in the scientific community is bound to continue. However, as Wired.com adds in another article;
"There is no accepted theoretical explanation of how high-temperature superconductors work either, but because the effect has been replicated so many times, nobody doubts that it happens."


ORIGINAL: Digital Journal}

martes, 14 de julio de 2015

Boeing just patented a jet engine powered by lasers and nuclear explosions


Last week, the US Patent and Trademark Office approved an application from Boeing's Robert Budica, James Herzberg, and Frank Chandler for a laser- and nuclear-driven airplane engine.

With airplane makers constantly on the lookout for new and more efficient ways to power their products, this laser engine is the latest idea cooked up by the engineers at Boeing.

  • Modern airliners such as the Boeing Dreamliner are powered by multiple turbofan engines These engines deploy a series of fans and turbines to compress air and ignite fuel to produce thrust.
Boeing's newly patented engine provides thrust in a very different and rather novel manner. According to the patent filing, the laser engine may also be used to power rockets, missiles, and even spacecraft.

As of now, the engine lives only in patent documents. The technology is so out-there that it is unclear whether anyone will ever build it.

Here's how Boeing's new patented engine works.

Boeing's new jet engine works by firing high-power lasers at radioactive material, such as deuterium and tritium.

The lasers vaporize the radioactive material and cause a fusion reaction — in effect a small thermonuclear explosion.

Hydrogen or helium are the exhaust byproducts, which exit the back of the engine under high pressure. Thrust is produced.

At the same time, the inside wall of the engine's thruster chamber — coated in uranium 238 — reacts with the high-energy neutrons produced by the nuclear reaction and generates immense heat.

The engine harnesses the heat by running coolant along the other side of the the uranium-coated combustion chamber.

This heat-energized coolant is sent through a turbine and generator that produces electricity to power the engine's lasers. Yes, lasers!

Other than the radioactive material, the engine requires very little in terms of external energy.

Here's Boeing's patent.

Check out the full video description courtesy of PatentYogi:

Boeing has patented nuclear powered aircrafts. The engines of these aircrafts include a unique propulsion system.

A stream of pellets containing nuclear material such as Deutrium or Tritium is fed into a hot-stop within a thruster of the aircraft. Then multiple high powered laser beams are all focused onto the hot-spot. The pellet is instantly vaporized and the high temperature causes a nuclear fusion reaction. In effect, it causes a tiny nuclear explosion that scatters atoms and high energy neutrons in all directions. This flow of material is concentrated to exit out of the thruster thus propelling the aircraft forward with great force.

And this is where Boeing has done something extremely clever. The inner walls of the thurster are coated with a fissile material like Uranium-238 that undergoes a nuclear fission upon being struck by the high energy neutrons. This releases enormous energy in the form of heat. A coolant is circulated along the inner walls to pick up this heat and power a turbine which in turn generates huge amounts of electric power. And guess what this electric power is used for? To power the same lasers that created the electric power! In effect, this space-craft is self-powered with virtually no external energy needed. 

Soon, tiny nuclear bombs exploding inside a plane may be business as usual.

Patent Information:
US 9,068,562

Laser-powered propulsion system 

Inventors: Budica; Robert J., Herzberg; James S., Chandler; Frank O.
Assignee: The Boeing Company (Chicago, IL) 
Family ID: 1000000999407
Appl. No.: 13/645,816
Filed: October 5, 2012

Abstract
A propulsion apparatus includes a propellant, at least one laser, and a thrust member. The propellant includes a solid surface having a hollow core disposed within the solid surface and a thrust-producing medium disposed within the hollow core. The at least one laser is positioned to vaporize the propellant with at least one laser-beam into a thrust-producing flow. The thrust member is for flowing within the thrust member a thrust-producing flow created by vaporization of the propellant.

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ORIGINAL: Business Insider

Jul. 7, 2015, 5:27 PM 

viernes, 6 de enero de 2012

New paper claims that the EM Drive doesn't defy Newton's 3rd law after all

By Elvis Popovic
So... it could still get us to Mars in 70 days?
Physicists have just published new calculations that suggest the controversial EM drive - or electromagnetic drive - could actually work, and doesn't defy Newton's third law after all.

In case you've missed the hype, here's a quick catch-up: a lot of space lovers are freaking out about the EM drive because of claims it could get humans to Mars in just 10 weeks, but just as many are sick of hearing about it, because, on paper at least, it doesn't work within the laws of physics.

Despite that not-insignificant setback, the EM drive shows no signs of quitting, and test after test - including trials by NASA scientists at the Eagleworks lab, and an independent researcher in Germany - has conceded that the propulsion system, somehow, does produce thrust.

Why is that so surprising? That's because of how the EM drive is supposed to work, in theory at least. First designed by British scientist Roger Shawyer back in 1999, the EM drive uses electromagnetic waves as fuel, and creates thrust by bouncing those microwaves back and forth within a metal cavity to trigger motion.

According to Shawyer's calculations, that could produce enough thrust to blast humans to Mars in just 70 days, and potentially even help us reach the next Solar System, Alpha Centauri, in just 92 years, all without the need for heavy, expensive rocket fuel.

That sounds pretty incredible, right? But there's one big problem - according to Newton's third law, everything must have an equal and opposite reaction, which means that something needs to be pushed out the back of propulsion system for it to move forwards. And, you pretty quickly see the dilemma - the EM drive doesn't use any fuel propellants, and so it doesn't have an exhaust, and so... it can't produce thrust. Even though it does.

Now that we've taken that round-trip right back to the dilemma we started with, let's present you with a potential solution, from physicists at the University of Helsinki in Finland. According to their new peer-reviewed study published in AIP Advances, the EM drive doesn't actually defy Newton's third law, because it does 

According to the researchers, the exhaust being blasted out is actually light, or more specifically, photons that have become paired up with another out-of-phase photon in order to shoot out of the metal cavity and produce thrust. 

So if that's the case, why hasn't anyone detected it before?

The researchers predict that's because photons need to become paired up in order to escape the fuel cavity, but the two photons in those pairs are out of phase, which means they completely cancel each other out and have no net electromagnetic field. If you think of it like waves of water, if the crest of one wave occurs at the exact same time as the trough of another, they'll cancel each other out and produce a flat patch of water - despite the fact that two waves are still passing through it. 

That's what's happening with the photons, so, in other words, the exhaust photons become invisible from an electromagnetic point of view because they're being masked by their out-of-sync partner.

"The EM drive operates by the same principle, for example, as a jet engine, where the high speed exhaust gases backwards (opposite reaction) push the airplane forwards," one of the researchers Arto Annila, told ScienceAlert over email. 

"Light at microwave lengths is the fuel that's being fed into the cavity ... and the EM drive exhausts backwards paired photons," he says. "When two photons travel together, but having opposite phases, then the pair has no net electromagnetic field, and hence it will not reflect back from the metal walls, but goes through."

And those escaping photons are the equal and opposite reaction that's producing the EM drive's thrust.

To be clear, this is just a hypothesis based on theoretical calculations. But it's not the first time photons have been used to propel spacecraft forward - it's also the idea that Bill Nye's solar sail is based on.

Annila is now hoping that engineers will take on the challenge of testing for these exhaust photon pairs in order to test whether their hypothesis holds up.

And that's going to be a challenge in itself, because without an electromagnetic signature, researchers are going to have to detect them by looking for "excess energy density above the surrounding background density of the gravitational field," Annila explained. That requires a device called an interferometer - not dissimilar to the ones that detect gravitational waves.

But if scientists can verify that these paired photons really are being pushed out the back, sh*t's going to get real for EM drives, because it'll help engineers design better cavities and produce even more thrust. 

"If our proposal is found worthy then EM drive research is no longer questioned but propelled," said Annila.

But as exciting as that is, for Annila the space travel aspect is less interesting than the fundamental physics behind the controversial propulsion system.

"In history often curious phenomena and perplexing observations have opened up a whole new paradigm," he says. Maybe this time, it'll open up a whole new pathway to the Universe. Watch this space.

ORIGINAL: Science Alert
FIONA MACDONALD
16 JUN 2016