Bristell turbine

[toto]

Nice. 

 

Turbotech turbine, who knows. But it looks like it’s actually flying, and doesn’t burn 35gph

 

[midlifeflyer]

Cool!

[GeeBee]

Purchase cost?

[A64Pilot]

57 minutes ago, GeeBee said:

Purchase cost?

If you have to ask 

[A64Pilot]

Starts like a Garrett, so I guess it’s single spool?

[GeeBee]

1 hour ago, A64Pilot said:

If you have to ask 

I'm guessing that heat exchanger is not cheap technology.

 

[toto]

Here’s the manufacturer’s site:

https://www.turbotech-aero.com/solutions/
 

The internet seems to have a $50k price floating around from a couple of years ago for the TP-R90, but I don’t see a price on the manufacturer site. 

Since $50k is for an experimental application, and that’s a couple of years ago, you’ve got to think it would be more expensive now. 

Still, if I’m going to spend $100k on an engine, give me a turbine that burns less than 10gph

 

[Bolter]

54 minutes ago, GeeBee said:

I'm guessing that heat exchanger is not cheap technology.

 

The heat exchanger is typically called a "recuperator" and recuperates waste heat from the exhaust back into the thermodynamic cycle of the gas turbine.  A land based gas turbine of similar size is from Capstone Turbine, and produced by the thousands since 1998, available today.  That recuperator is very effective, doubling the total gas turbine cycle efficiency (from about 15% to about 30%), but very heavy, as it is land based.  It proves the cycle out, but not aerospace ready.  The cost of the recuperator is a major portion of the total system cost, just as it is a major part of the weight, not just an accessory.  

For aircraft, the recuperator effectiveness will depend greatly on size and therefore weight.  Very difficult to make a solution that meets weight and cost targets.  It is also a highly aggressive environment of massive thermal cycles from cold soak to +1000F exhaust temp on the hot side, plus a thermal differential with maybe 400F on the cold side.  The exhaust gas is also highly corrosive at these temperatures, requiring fancier alloys (including Inconel 625 as a popular choice)

Turb-Aero (https://turb.aero/) has a similar solution but with 2 spools like PT6.  Also a long way from being availble for sale.  

-dan

[aviatoreb]

That does seem extremely appealing.  What's the catch?

[GeeBee]

1 hour ago, Bolter said:

The heat exchanger is typically called a "recuperator" and recuperates waste heat from the exhaust back into the thermodynamic cycle of the gas turbine.  A land based gas turbine of similar size is from Capstone Turbine, and produced by the thousands since 1998, available today.  That recuperator is very effective, doubling the total gas turbine cycle efficiency (from about 15% to about 30%), but very heavy, as it is land based.  It proves the cycle out, but not aerospace ready.  The cost of the recuperator is a major portion of the total system cost, just as it is a major part of the weight, not just an accessory.  

For aircraft, the recuperator effectiveness will depend greatly on size and therefore weight.  Very difficult to make a solution that meets weight and cost targets.  It is also a highly aggressive environment of massive thermal cycles from cold soak to +1000F exhaust temp on the hot side, plus a thermal differential with maybe 400F on the cold side.  The exhaust gas is also highly corrosive at these temperatures, requiring fancier alloys (including Inconel 625 as a popular choice)

Turb-Aero (https://turb.aero/) has a similar solution but with 2 spools like PT6.  Also a long way from being availble for sale.  

-dan

So basically you confirm my guess

[AH-1 Cobra Pilot]

This has lots of promise to make turbines cheaper:  

 

[Pinecone]

Based on the data on the Bristell site, the engine produces 130 HP and burns 25 liters per hour at 75% power.  So 3.9 HP per liter per hour.

So, take my 252/Encore at 220 HP, I cruise at about 64% power on 10.1 GPH (38.23 LPH) or about 138 HP.  So should be about 9.4 GPH for that power.   Hmmmm.

Or cruise at 75% power and faster speed on 11.2 GPH.

187 pounds complete.

I am ready.

 

[aviatoreb]

There is an interesting hybrid electric on their website too.  I know what hybrid electric means in car - but in airplanes....  can it be setup differently.  Suppose this engine likes to cruise at 130hp all day long.  But we still want 225hp for short phases of flight like take off and landing - I could see the utility of hybrid electric where the average could be 130hp but electric is there and able to produce that 225hp for take off and landing phases.  Can it do this?

[AH-1 Cobra Pilot]

Just doing the Math gives this engine a Specific Fuel Consumption of 0.345.  That is pretty close to a big Cat diesel.  If it sounds too good to be true...

[Schllc]

Those two engines on a Comanche at 11 gallons an hour would have some range.  Especially if it’s efficient at 25k

plenty of fuel capacity  

how cool would a turbine twinkie be?