skycowboy

Guys (and gals - vag), has anyone heard of or have any links for any new AVIATION propulsion technologies being looked at? I did a search today and found nothing but stuff for spacecraft... I am interesting in any new technologies emerging for things that fly, within the atmosphere (of earth) that is...

POPA

I have, in fact, heard of a new propulsion system.
I forget the specifics, but I know it involved beans and hot sauce...

rickair7777

Gas Turbine Engines (turbofans and turboprops) are about the ultimate technology for passenger aircraft, unless you consider possible unknown technologies. The only advances you are likely to be seeing in the mid-term are refinements to improve efficiency, and modification to allow the use of alternative fuels.

For non-passenger applications where endurance is more important than speed, solar/battery powered propellers combined with a high aspect-ratio wing are likely to be employed eventually.

You could theoretically drive a ducted fan engine with an electric motor, but you would still need jet engines (giant APUs) to power it. This kind of scheme may have some advantages over direct-drive fans, but currently the effeciency losses in generating and transferring the electrical power are too high. Some of the advantages would include turning off one of the big APU's for cruise flight to save wear-and-tear, and allowing the big APU's to operate at their most effecient speed at all times (like our small APU's do today).

schone

DAL came out with a press release about 3-4 months ago that they will be teaming up with this company to come up with a new APU like system that'll enable airplanes to taxi on that alone instead of thier own engines allowing planes to start the engines next to the runway, thus saving fuel costs.

Also the kicker to this system was coming up with a technological solution to get rid of pushback procedures and tugs..... allowing the airplanes to pushback themselves automatically without guidance or atleast using thier own propulsion.

http://cincinnati.bizjournals.com/ci...6/daily53.html

ToiletDuck

You guys are forgetting propane powered and fuel cells along with diesel. There was a picture of an alternative fuel jet out there. Went over it in one of our classes. I'll see if I can dig it up.

ToiletDuck

They already have those for inner planet surveillance. Can stay airborne for up to 45 days.

There is also electric propulsion where the power is beamed to the aircraft via lasers. I've seen video of this working on small scale several years ago. They were shooting a small satellite about 50ft up in the air. Very very cool stuff. There is also talks of beaming power to aircraft using different methods that don't require direct line of sight. Kinda like a radio wave. There's hydrogen slush and the new "pulse" thing they are doing which pushed some jet to like mach 13.

blastboy

!LOL! I would be fit for that propulsion system.

On a more serious note, I have heard about some sort of electro-magnetic propulsion system in the thoughts of NASA and the Europeans. It's not even in the drawing boards. Uses no combustable fuels. It's just something I overheard at a gathering.

rickair7777

An MHD system might be able to move air to create thrust, but it would take a LOT of electrical power. That's the real problem for airliners...where do you get that much power from? A magnetic system might be used to create thrust but it does nothing to generate the necessary power...you still need an electrical generator powered by something...

Conveniently gas-turbine engines have a higher power-to-weight ratio than anything except rocket engines. That's why they will be nearly impossible to replace

rickair7777

Diesel and Jet A are almost the same thing..almsot no point in developing that for turbine airplanes.

A Diesel/Jet A piston engine makes sense obviously, due to the availability of Jet A at airports.

Cubdriver

There's nothing that even comes close to hydrocarbon fuels for subsonic aircraft propulsion. Short of a breakthrough, you will see relatively minor improvements in mass flow rates (bigger bypass fans), better blade designs that delay critical mach a little higher, maybe a little bit of increase in the upper combustion temperature. Actually, there is a very nice study going on now at Georgia Tech in this regard- they have a new design for a simplified combustor that raises the maximum possible operating temperature.

Other areas that will see the most development in the next 30 years will be in the areas of materials and aerodynamics. There is something called closed circulation wing, that has been around for years but has never been adequately developed. NASA has recently been reviving its effort to develop the wing. It removes the need for any kind of mechanical high lift device such as flaps and slats. It basically re-energizes the boundary layer around the wing using bleed air from an engine. The simplicity of it brings down weight down and makes for smaller, lighter, less draggy wings. Another big idea is the active aeroelastic wing that removes the need for inboard and outboard ailerons. Again there is a savings of weight and a corresponding jump in overall efficiency.

In materials we already have carbon fiber composites, but they will see wider applications as manufacturing techniques become cheaper. What aluminum did to cloth and tubes composites will do to aluminum as the ability to use them improves. I wouldn't look to propulsion for a miracle; other areas are developing faster now.