Full Version: New be Qustion Turbine ?
He any one know of a turbine on a 914? My project just might need it..
Huge deal, and generally a terrible idea. Gas turbines are very inefficient at light loads, have response lag that makes the worst turbo setup seem instantaneous, and require major re-engineering of everything.
It's hard to find a transmission and clutch/flywheel combo that will work with a motor that spins at 75,000rpm
-Ben M.
-Ben M.
| QUOTE (airsix @ Aug 30 2005, 12:19 PM) |
| It's hard to find a transmission and clutch/flywheel combo that will work with a motor that spins at 75,000rpm |
Two words...Gear Reduction.
I wonder if Kennedy has a adapter for the 901 tranny?
about 20 years ago a dude did it to a vette.
he had DUAL disk brakes on each wheel.
just about gutted a torque converter for a VERY high stall speed.
used the entire underside of the car for a muffler that looked like
[========]
...U............U...
cuz it's got a lot of air flow going through it.
it would however do 200+MPH and smoke em in every gear.
he had DUAL disk brakes on each wheel.
just about gutted a torque converter for a VERY high stall speed.
used the entire underside of the car for a muffler that looked like
[========]
...U............U...
cuz it's got a lot of air flow going through it.
it would however do 200+MPH and smoke em in every gear.
aaaaaaaaaaaaaaa
Ummn,
Prior T-58 (1750 SHP) & T-64 (4340SHP) Tech here.....
The problem with using a Turboshaft engine is the fact that most of them are designed to operate at 100% Ng (gas generator speed) the speed of the aircraft is varied by the pitch variance of the rotor blades or prop.
Basically there is really no good way to create a variable throttle because the fuel control only has 3 positions (18%, 56% ground idle and 100%) The fuel control is alot like a fuel distributor on a CIS injected vehicle and there is no really easy way to change its internals to allow variable throttle.
In the Abrams tanks the drive is hydrostatically controlled to achieve the speed that the operator wants, almost like a Bulldozer. The engine operates at 100% and drives a hydraulic pump that creates pressure to move the vehicle at variable speeds.
I have worked out a way to allow for a variable fuel control but it would be very expensive to create and would also be risky and could create a gas generator failure or combustor failure if the fuel mix was not perfect. The combustor can easily explode if the proper mix ratios are not adhered to during throttle up... basically a lean out could blow your car to hell and you with it....
Why have I been working on this- because I wanna use a T-58 Midship in a VW bus!!!!!
Ok... If you are gonna use a Turboshaft in a 914 I'd start with a T400 pack or a T700 pack. Both of which are much more compact than the T58 16 stage engine that I'd want to use in the bus- its almost 6 feet long but only weighs 415 pounds!
One thing that you have to remember is that a Turbine engine has to have very HI RPM to even start. This speed cannot be attained with an electric starter-you would need 3,000 PSI and a 10" accumulator to dump the pressure into the starter. In Helos these are manually pumped systems (some are electro mechanical nowdays) that take a solid 5 minuts of pumping to work up to 3,000 PSI just to fire up the APP (Auxiliary power plant) which is a small 110 SHP Turbine that provides power for the #1 Hydraulics system which provides Hydro pressure for the main engine starters to operate... The engine won't self sustain until you have 18% Ng or about 1500 RPM...
It could be done in a 914- I'd help anyone that wanted to do it and I have hook ups for the engines that no longer are airworthy....
Yes- I'm crazy
Prior T-58 (1750 SHP) & T-64 (4340SHP) Tech here.....
The problem with using a Turboshaft engine is the fact that most of them are designed to operate at 100% Ng (gas generator speed) the speed of the aircraft is varied by the pitch variance of the rotor blades or prop.
Basically there is really no good way to create a variable throttle because the fuel control only has 3 positions (18%, 56% ground idle and 100%) The fuel control is alot like a fuel distributor on a CIS injected vehicle and there is no really easy way to change its internals to allow variable throttle.
In the Abrams tanks the drive is hydrostatically controlled to achieve the speed that the operator wants, almost like a Bulldozer. The engine operates at 100% and drives a hydraulic pump that creates pressure to move the vehicle at variable speeds.
I have worked out a way to allow for a variable fuel control but it would be very expensive to create and would also be risky and could create a gas generator failure or combustor failure if the fuel mix was not perfect. The combustor can easily explode if the proper mix ratios are not adhered to during throttle up... basically a lean out could blow your car to hell and you with it....
Why have I been working on this- because I wanna use a T-58 Midship in a VW bus!!!!!
Ok... If you are gonna use a Turboshaft in a 914 I'd start with a T400 pack or a T700 pack. Both of which are much more compact than the T58 16 stage engine that I'd want to use in the bus- its almost 6 feet long but only weighs 415 pounds!
One thing that you have to remember is that a Turbine engine has to have very HI RPM to even start. This speed cannot be attained with an electric starter-you would need 3,000 PSI and a 10" accumulator to dump the pressure into the starter. In Helos these are manually pumped systems (some are electro mechanical nowdays) that take a solid 5 minuts of pumping to work up to 3,000 PSI just to fire up the APP (Auxiliary power plant) which is a small 110 SHP Turbine that provides power for the #1 Hydraulics system which provides Hydro pressure for the main engine starters to operate... The engine won't self sustain until you have 18% Ng or about 1500 RPM...
It could be done in a 914- I'd help anyone that wanted to do it and I have hook ups for the engines that no longer are airworthy....
Yes- I'm crazy
In the early 1960s, Rover, in a joint venture with BRM, made a gas-turbine sports car for use at Le Mans. The driver was Graham Hill. The throttle was on or off, no variation. Indeed, the "throttle" was nothing more than a button on the floor. Hill had to adopt a technique of braking way before the turn, then pushing the "throttle" button way before the apex, and if he judged it right, the engine would spool up and accelerate just prior to the apex and around it. Too late, and he was very slow off the turn. Too early, and it was a handful keeping it on the track.
They ran it for two years, and gave up on the idea.
There was also a gas turbine car at Indy, which was more successful since throttle control isn't much of an issue on a superspeedway.
The only viable way I can think of to use a gas turbine in a road car would be to have the turbine spin a generator and have electric motors drive the wheels, or do the hydrostatic thing like the tanks do. In either case, the turbine is never connected to the wheels, so no need for serious gear reduction. No need for a gearbox at all, in fact. The turbine only has to run at full throttle, or off, depending on how much electric power you required. Run it on batteries only around town, and fire up the turbine for freeway cruising.
They ran it for two years, and gave up on the idea.
There was also a gas turbine car at Indy, which was more successful since throttle control isn't much of an issue on a superspeedway.
The only viable way I can think of to use a gas turbine in a road car would be to have the turbine spin a generator and have electric motors drive the wheels, or do the hydrostatic thing like the tanks do. In either case, the turbine is never connected to the wheels, so no need for serious gear reduction. No need for a gearbox at all, in fact. The turbine only has to run at full throttle, or off, depending on how much electric power you required. Run it on batteries only around town, and fire up the turbine for freeway cruising.
hey jake,
how about the turbine in the Y2K bike RR Allison 250 series?!?
there is a turbine truck on that site too.
how about the turbine in the Y2K bike RR Allison 250 series?!?
there is a turbine truck on that site too.
| QUOTE (Jake Raby @ Aug 30 2005, 01:11 PM) |
| ... the APP (Auxiliary power plant) which is a small 110 SHP Turbine that provides power for the #1 Hydraulics system which provides Hydro pressure for the main engine starters to operate... It could be done in a 914- I'd help anyone that wanted to do it and I have hook ups for the engines that no longer are airworthy.... Yes- I'm crazy |
Crazy or rich? Even old APPs can go for >$100,000 !!!!!!!!!!
-Ben M.
ps - As a kid I worked for a big FBO/flightschool. When they won an APP at an auction one of the guys took a bedroll, his german sheppard, and an AR15 and camped next to it until the truck came. Why? They'd had items like that dissapear in the night after an auction before.
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