Steam turbine driven turbojet
Posted by novice
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Re: Steam turbine driven turbojet May 30, 2019 08:10PM |
Hi Steve,
OK...yes, I would love to share ideas on a forced circulation system. We can do it on a new thread?
However, I'm leaning towards a combination natural circulation with significant feed water generation. One of my latest concepts attached.
Its late and got to go to bed,
Kind regards,
Rick
OK...yes, I would love to share ideas on a forced circulation system. We can do it on a new thread?
However, I'm leaning towards a combination natural circulation with significant feed water generation. One of my latest concepts attached.
Its late and got to go to bed,
Kind regards,
Rick
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Re: Steam turbine driven turbojet June 10, 2019 06:46PM |
Hypothetical design parameters of the 1942 Leduc's steam turbine thermojet aircraft engine based on 1940 Campini-Caproni prototype:
Boiler efficiency -90%
Steam pressure- 1910 psi
Steam temperature - 1000 F
Steam turbine exhaust - 50 psi
Condensing steam temperature - 298 F
Turbine power - 900 kW/1206 hp@85% efficiency
Energy flow in- 15.1 MMBtu/hr
Steam condenser capacity - 12.1 MMBtu/hr
Steam flow- 10200 lbs/hr
Boiler water feed pump - 45 kW
Compressed air exhaust temperature before jet nozzle- 244 F
Ambient temperature - 86 F
Fan pressure ratio - 1.25
Nozzle pressure ratio -1.15
Air flow- 90 lbs/s
Exhaust velocity- 560 ft/s.
Thrust-1560 lbs
Fuel consumpution static full power-133 gallons/hr
For comparison, propeller driven by the same steam turbine can produce 3000-3500 lbs depending on its diameter.
At very high altitude and speed situation is opposite.
Propeller is producing much less thrust than thermojet.
At 30000 ft and 500 mph:
Fan pressure ratio-1.4
Ram pressure @0.97 inlet efficiency-1.38
Pressure ratio before jet nozzle @0.93 condenser pressure- 1.8
Jet exhaust- 244 F
Jet velocity 1200 ft/s @0.97 nozzle efficiency
Air flow -67 lbs/s
Jet thrust- 974 lbs
At L/D ratio 16.0- aircraft weight is 15000 lbs
Net propulsive power - 969 kW/1298 hp.
It is more than steam turbine's power 1206 hp!
This is the main advantage of this aircraft engine.
Air goes to the boiler already being pressurized in inlet and fan. This allows to have constant boiler output at higher altitudes.
Main disadvantage is low takeoff thrust. To improve it a propeller and variable jet nozzle are required.
If useful fuel weight is 20% of aircraft weight - 3000 lbs, this aircraft can fly 3 hours at 500 mph@30000ft.
Edited 6 time(s). Last edit at 06/10/2019 08:28PM by novice.
Boiler efficiency -90%
Steam pressure- 1910 psi
Steam temperature - 1000 F
Steam turbine exhaust - 50 psi
Condensing steam temperature - 298 F
Turbine power - 900 kW/1206 hp@85% efficiency
Energy flow in- 15.1 MMBtu/hr
Steam condenser capacity - 12.1 MMBtu/hr
Steam flow- 10200 lbs/hr
Boiler water feed pump - 45 kW
Compressed air exhaust temperature before jet nozzle- 244 F
Ambient temperature - 86 F
Fan pressure ratio - 1.25
Nozzle pressure ratio -1.15
Air flow- 90 lbs/s
Exhaust velocity- 560 ft/s.
Thrust-1560 lbs
Fuel consumpution static full power-133 gallons/hr
For comparison, propeller driven by the same steam turbine can produce 3000-3500 lbs depending on its diameter.
At very high altitude and speed situation is opposite.
Propeller is producing much less thrust than thermojet.
At 30000 ft and 500 mph:
Fan pressure ratio-1.4
Ram pressure @0.97 inlet efficiency-1.38
Pressure ratio before jet nozzle @0.93 condenser pressure- 1.8
Jet exhaust- 244 F
Jet velocity 1200 ft/s @0.97 nozzle efficiency
Air flow -67 lbs/s
Jet thrust- 974 lbs
At L/D ratio 16.0- aircraft weight is 15000 lbs
Net propulsive power - 969 kW/1298 hp.
It is more than steam turbine's power 1206 hp!
This is the main advantage of this aircraft engine.
Air goes to the boiler already being pressurized in inlet and fan. This allows to have constant boiler output at higher altitudes.
Main disadvantage is low takeoff thrust. To improve it a propeller and variable jet nozzle are required.
If useful fuel weight is 20% of aircraft weight - 3000 lbs, this aircraft can fly 3 hours at 500 mph@30000ft.
Edited 6 time(s). Last edit at 06/10/2019 08:28PM by novice.
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Re: Steam turbine driven turbojet June 21, 2019 04:47PM |
May 1954 aircraft propulsion study by Fraas and Savolainen:
Vapor-Cycle Compressor-jet
The wide-spread use of vapor cycles has directed attention to water as a working fluid for the thermodynamic cycle of an aircraft power plant. The principal difficulty associated with such a power plant is the size, weight, and drag associated with the condenser. In attempting to establish the proportions of such a power plant, it soon became evident that only by going to high temperatures and pressures and by using the cycle in conjunction with a compressor-jet engine could a reasonably promising set of performance characteristics be obtained by superimposing the water-vapor cycle on a compressor-jet cycle, the power generated in the steam turbine could be used to drive the air compressor, while the condenser that would serve as the heat dump for the steam cycle could also serve to heat the air of the compressor-jet cycle.With this arrangement, the air pressure drop across the condenser could be kept from imposing an intolerable drag penalty on the airplane.
Optimum speed for steam compressor jet aircraft is around Mach 0.9 at 30,000-40,000 ft crusing altitude. That is even slightly faster than Boeing 747 speed.
Net energy efficiency of such aircraft is around 20% , which is equal or slightly higher than efficiency of Boeing 707. Weight of the steam engine with boiler and water is 2-3 times higher than weight of the gas turbine engine.
.
Edited 3 time(s). Last edit at 06/21/2019 05:21PM by novice.
Vapor-Cycle Compressor-jet
The wide-spread use of vapor cycles has directed attention to water as a working fluid for the thermodynamic cycle of an aircraft power plant. The principal difficulty associated with such a power plant is the size, weight, and drag associated with the condenser. In attempting to establish the proportions of such a power plant, it soon became evident that only by going to high temperatures and pressures and by using the cycle in conjunction with a compressor-jet engine could a reasonably promising set of performance characteristics be obtained by superimposing the water-vapor cycle on a compressor-jet cycle, the power generated in the steam turbine could be used to drive the air compressor, while the condenser that would serve as the heat dump for the steam cycle could also serve to heat the air of the compressor-jet cycle.With this arrangement, the air pressure drop across the condenser could be kept from imposing an intolerable drag penalty on the airplane.
Optimum speed for steam compressor jet aircraft is around Mach 0.9 at 30,000-40,000 ft crusing altitude. That is even slightly faster than Boeing 747 speed.
Net energy efficiency of such aircraft is around 20% , which is equal or slightly higher than efficiency of Boeing 707. Weight of the steam engine with boiler and water is 2-3 times higher than weight of the gas turbine engine.
.
Edited 3 time(s). Last edit at 06/21/2019 05:21PM by novice.
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Re: Steam turbine driven turbojet July 17, 2019 05:18AM |
Hi Novice,
Need your help? BTW, I thoroughly enjoy this thread
So I have a question, has there been any development of a value for a Boiler HP rating based on square feet (any unit will work)? So I'm sure you know the equation.
Conduction: Q=kA Delta T
Also consider an element, a mono tube in this quest. So here is the challenge, this is the heat transfer to water. I have attached the thermal conductivity of water and steam. This leads to the determination of a boundary layer that gets turned to steam and is replaced with water...theory that I've been thinking about.
Here is some information, similar to what I'm looking for, that I gathered from another steam guy whom I have great respect. This given a wood fire and typically a boat type boiler:
1) Fire Tube Boiler - 10 Sq Ft / BHP
2) Water Tube Boiler - 5 Sq Ft / BHP
3) Mono Tube Boiler - 2 Sq Ft / BHP
I would like to use number 3 value in the case of my Ofeldt boiler considering the operating temperatures. When I apply this, I get ~ 6 BHP. Boiler picture attached. Note that this is not a Mono Tube Boiler and would be considered a Water Tube Boiler. The value is and result is suitable to my needs in the intended Car I'm building. However, not substantiated.
Other considerations come into play like flow rate, turbulence and materials used. As far as materials and in order to create an effective boiler system, I'm leaning toward SS tube sizes 1/4, 3/8 & 1/2. The assumption is that the SS would provide instantaneous heat to the water. Again back to the boundary layer theory.
Again, looking for a rating, Sq Ft / BHP of mono tube(s)? Don't hesitate to ask questions.
Kind regards,
Rick
Need your help? BTW, I thoroughly enjoy this thread
So I have a question, has there been any development of a value for a Boiler HP rating based on square feet (any unit will work)? So I'm sure you know the equation.
Conduction: Q=kA Delta T
Also consider an element, a mono tube in this quest. So here is the challenge, this is the heat transfer to water. I have attached the thermal conductivity of water and steam. This leads to the determination of a boundary layer that gets turned to steam and is replaced with water...theory that I've been thinking about.
Here is some information, similar to what I'm looking for, that I gathered from another steam guy whom I have great respect. This given a wood fire and typically a boat type boiler:
1) Fire Tube Boiler - 10 Sq Ft / BHP
2) Water Tube Boiler - 5 Sq Ft / BHP
3) Mono Tube Boiler - 2 Sq Ft / BHP
I would like to use number 3 value in the case of my Ofeldt boiler considering the operating temperatures. When I apply this, I get ~ 6 BHP. Boiler picture attached. Note that this is not a Mono Tube Boiler and would be considered a Water Tube Boiler. The value is and result is suitable to my needs in the intended Car I'm building. However, not substantiated.
Other considerations come into play like flow rate, turbulence and materials used. As far as materials and in order to create an effective boiler system, I'm leaning toward SS tube sizes 1/4, 3/8 & 1/2. The assumption is that the SS would provide instantaneous heat to the water. Again back to the boundary layer theory.
Again, looking for a rating, Sq Ft / BHP of mono tube(s)? Don't hesitate to ask questions.
Kind regards,
Rick
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Re: Steam turbine driven turbojet August 07, 2019 06:42PM |
Steam turboprop design drawings and calculation.
Flight speed 200-500 mph, altitude 15000-30000ft.
Flight speed 200-500 mph, altitude 15000-30000ft.
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Re: Steam turbine driven turbojet August 27, 2019 06:59PM |
There is a lot of factors working against us to generating steam such as Cv goes down as temperature goes up and water density reacts the same. These things makes it harder to design for and plan to make steam.
I sketched out what might help a mono-tube generator be a little more efficient. With this concept I can provide evidence that when you add fill to a tube, it will generate steam faster or in a shorter tube length.
I sketched out what might help a mono-tube generator be a little more efficient. With this concept I can provide evidence that when you add fill to a tube, it will generate steam faster or in a shorter tube length.
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Re: Steam turbine driven turbojet August 16, 2020 02:55PM |
Liquid metals(molten sodium, potassium and mercury) and high boiling temperature organic liquids were also studied for closed Rankine cycle aerial vehicles propulsion.
[archive.org]
A study of various advanced powerplants for a large helicopter:
Closed Brayton cycle gas turbine (heavy oil fuel, coal, boron, metals)
Potassium metal closed Rankine cycle (heavy oil fuel, coal, boron, metals)
Mercury closed Rankine cycle (heavy oil fuel, coal, boron, metals)
Organic Rankine cycle (heavy oil fuel, coal, boron, metals)
Recuperated intercooled turboshaft turbine
Fuel cell electric drive (hydrogen, jet fuel)
Magnetohydrodynamic electric drive (jet fuel, heavy oil, hydrogen)
Thermionic electric drive (heavy oil, solid fuel)
Fission energy powered cycle turbines (Rankine and Brayton.
Calculations were made for 500, 1500 and 10000 hp powerplants. Each helicopter has 2 such powerplants.
Potassium metal Rankine helicopter 2x10000hp powerplant with all fuel aboard(25,000 lbs) is about 85,000 lbs with 1969s technology and 45,000 lbs (fuel-20,000 lbs) with 2020 technology. Efficiency is around 30%.
Mercury poweplant is 5 times heavier , occupies 9 times larger volume and has only 15% efficiency.
Cost is high due to use of molybdenum and tantalum alloys. Turbine seals leak is very serious problem for this power plant, especially for molten potassium.
Organic Rankine cycle has about the same weight and efficiency as potassium powerplant, but requires 3.5 times larger volume.
Water steam powerplant was not studied but is probably could have parameters close to mercury powerplant or worse.
[archive.org]
A study of various advanced powerplants for a large helicopter:
Closed Brayton cycle gas turbine (heavy oil fuel, coal, boron, metals)
Potassium metal closed Rankine cycle (heavy oil fuel, coal, boron, metals)
Mercury closed Rankine cycle (heavy oil fuel, coal, boron, metals)
Organic Rankine cycle (heavy oil fuel, coal, boron, metals)
Recuperated intercooled turboshaft turbine
Fuel cell electric drive (hydrogen, jet fuel)
Magnetohydrodynamic electric drive (jet fuel, heavy oil, hydrogen)
Thermionic electric drive (heavy oil, solid fuel)
Fission energy powered cycle turbines (Rankine and Brayton.
Calculations were made for 500, 1500 and 10000 hp powerplants. Each helicopter has 2 such powerplants.
Potassium metal Rankine helicopter 2x10000hp powerplant with all fuel aboard(25,000 lbs) is about 85,000 lbs with 1969s technology and 45,000 lbs (fuel-20,000 lbs) with 2020 technology. Efficiency is around 30%.
Mercury poweplant is 5 times heavier , occupies 9 times larger volume and has only 15% efficiency.
Cost is high due to use of molybdenum and tantalum alloys. Turbine seals leak is very serious problem for this power plant, especially for molten potassium.
Organic Rankine cycle has about the same weight and efficiency as potassium powerplant, but requires 3.5 times larger volume.
Water steam powerplant was not studied but is probably could have parameters close to mercury powerplant or worse.
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Re: Steam turbine driven turbojet August 17, 2020 10:56PM |
Rick.H Wrote:
> Another thing is to get to super critical (SC)
> steam. The pictures posted above, from my
> experience, won't produce SC steam. I'm
> thinking...the way to SC is to have a secondary
> boiler or 2nd stage boiler that takes boiler water
> and pumps it up to 3,000 PSI along with a super
> heat to 700 F. Any diagrams or information on
> going SC?
My boiler does exactly that.
The compressor (on the right) pressurizes the container to 3500psi...and keeps it pressurized.
The tubes inside are electric heating elements.... heats everything to 1000F *after* it is pressurized.
Voila! SC Steam. Total energy spent = about 1400btu/lb
It was designed for a USC Coal powerplant, (USC Steam Turbine), and the very next day Greta showed up and ruined everything.
> Another thing is to get to super critical (SC)
> steam. The pictures posted above, from my
> experience, won't produce SC steam. I'm
> thinking...the way to SC is to have a secondary
> boiler or 2nd stage boiler that takes boiler water
> and pumps it up to 3,000 PSI along with a super
> heat to 700 F. Any diagrams or information on
> going SC?
My boiler does exactly that.
The compressor (on the right) pressurizes the container to 3500psi...and keeps it pressurized.
The tubes inside are electric heating elements.... heats everything to 1000F *after* it is pressurized.
Voila! SC Steam. Total energy spent = about 1400btu/lb
It was designed for a USC Coal powerplant, (USC Steam Turbine), and the very next day Greta showed up and ruined everything.
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Re: Steam turbine driven turbojet August 18, 2020 12:10PM |
Kyle,
You're toying with my dreams
I'm curious to know if USC Coal power plant was to use the SC Steam through their steam turbine? I know there are bucket blade coatings that can handle it...worked short stint at Chromalloy NY. One of the common coatings is chrome...makes sense.
Chromalloy NY Website
It don't know if I ever said this story about being an Engineer at Teledyne CAE and working in the Altitude Test Chamber. Anyways, point is that I would walk by the 1,000 psi compresser every day entering into the test chamber(s) and the tank that showed a pressure gage at 1,000 psi. That's allot of pressure. Then to image what a compressor would look like to go SC or > 3,000 psi, not sure what that is or would look like? Some points to consider are going from a 120 psi machine to a 1,000 psi, the size is the same, wall thickness is 3X, pipe size is 1/3X sch 80, motor is 3X, 2X stages compound; all the sizes relationships. It looks like a compressor on steroids. Not that the compressor had to run all night to get to 1,000 psi.
All designs look good on paper. Any test results from a prototype? Was one built?
Cheers,
Rick
You're toying with my dreams
I'm curious to know if USC Coal power plant was to use the SC Steam through their steam turbine? I know there are bucket blade coatings that can handle it...worked short stint at Chromalloy NY. One of the common coatings is chrome...makes sense.
Chromalloy NY Website
It don't know if I ever said this story about being an Engineer at Teledyne CAE and working in the Altitude Test Chamber. Anyways, point is that I would walk by the 1,000 psi compresser every day entering into the test chamber(s) and the tank that showed a pressure gage at 1,000 psi. That's allot of pressure. Then to image what a compressor would look like to go SC or > 3,000 psi, not sure what that is or would look like? Some points to consider are going from a 120 psi machine to a 1,000 psi, the size is the same, wall thickness is 3X, pipe size is 1/3X sch 80, motor is 3X, 2X stages compound; all the sizes relationships. It looks like a compressor on steroids. Not that the compressor had to run all night to get to 1,000 psi.
All designs look good on paper. Any test results from a prototype? Was one built?
Cheers,
Rick
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Re: Steam turbine driven turbojet August 19, 2020 01:27PM |
Rick.H Wrote:
>
> I'm curious to know if USC Coal power plant was to
> use the SC Steam through their steam turbine?
Yes it was designed to work directly with the SC steam turbine, and from there it would be the usual reheat and send to the IP and LP turbines.
>
> It don't know if I ever said this story about
> being an Engineer at Teledyne CAE
Teledyne would have been a dream job for me! Heard a lot about them back in the day.
> All designs look good on paper. Any test results
> from a prototype? Was one built?
Yes I built a couple. In the pictures, the 4000-psi compressor is on the right and the 3kW induction heater is on the left.
Two things happened: My parents both died, and I ran out of (everything, time, money, ability) so that's as far as I got.
It is easy making SC Steam (fluid) in an enclosed tank. The HARD part is using it, because everything downstream of the tank (pipes, fittings, expanders, etc) have to be able to tolerate SC pressure and temp.
-Kyle
>
> I'm curious to know if USC Coal power plant was to
> use the SC Steam through their steam turbine?
Yes it was designed to work directly with the SC steam turbine, and from there it would be the usual reheat and send to the IP and LP turbines.
>
> It don't know if I ever said this story about
> being an Engineer at Teledyne CAE
Teledyne would have been a dream job for me! Heard a lot about them back in the day.
> All designs look good on paper. Any test results
> from a prototype? Was one built?
Yes I built a couple. In the pictures, the 4000-psi compressor is on the right and the 3kW induction heater is on the left.
Two things happened: My parents both died, and I ran out of (everything, time, money, ability) so that's as far as I got.
It is easy making SC Steam (fluid) in an enclosed tank. The HARD part is using it, because everything downstream of the tank (pipes, fittings, expanders, etc) have to be able to tolerate SC pressure and temp.
-Kyle
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Re: Steam turbine driven turbojet September 23, 2020 05:10PM |
Steam turbine assisted aircraft turbojet engines patents:
GB2334556A United Kingdom
Turbojet with steam turbine
[patentimages.storage.googleapis.com]
Abstract
The Thermo Induction Turbojet operates by drawing in air and compressing it in an axial flow compressor 1. Front here it is passed into combustion chamber 6 where it is mixed with fuel from nozzles 5 and burnt. The rapidly expanding hot gases pass around convoluted water tube 10 and over encased steam turbine 3, exiting through jet nozzle 12. Water supplied from pump 8 is force circulated through water tube 10. This cools the combustion chamber and produces high pressure steam. The steam is fed via nozzles 11 to steam turbine 3, thus rapidly rotating it, the connecting shaft 2 and compressor 1. Exhausted steam exits the turbine via ducts 13 and manifold 14. From here it travels via pipe 15 to a suitable condenser in the front of the engine. Condensed water is recirculated via pump 8.
Working model of this engine was built by inventor.
[youtu.be]
US4333309A United States
Steam assisted gas turbine engine
[patentimages.storage.googleapis.com]
Abstract
A gas turbine engine is disclosed which has an integral steam power system consisting of heat absorbing boilers which convert an unpressurized liquid into an expanded and heated steam by utilizing heat normally lost through component cooling systems and the exhaust system. Upon completion of the steam power cycle, the steam is condensed back to a liquid state through a condensing system located within the compressor and other functional components of the gas turbine engine. A system of high pressure air and friction seals restrict steam or liquid condensate within designed flow bounds. The gas turbine engine disclosed is designed to give improved fuel efficiency and economy for aircraft and land use applications.
US2159758A United States
Power plant - steam assisted aircraft powerplant
[patentimages.storage.googleapis.com]
US6786036B2 United States
Bimodal fan, heat exchanger and bypass air supercharging for piston or rotary driven turbine
[patentimages.storage.googleapis.com]
Abstract
The present invention relates to turbine fan aircraft use. In particular, the present invention is directed toward a turbine fan driven by a piston or rotary (e.g., Wankel) engine. The present invention makes possible the most flexible and effective installation of a ducted fan with a fixed horsepower source, namely a conventional internal combustion engine. Effectiveness being defined as full utilization of the engine's available horsepower at the chosen flight points. In a further embodiment of the present invention, a novel heat exchanger may be provided which removes waste heat with minimal drag while boosting the fan system's effective thermal efficiency by increasing the enthalpy of the working fluid. In yet another embodiment of the present invention, bypass air from the turbine may be used to supercharge the piston or rotary engine.
Edited 1 time(s). Last edit at 09/23/2020 05:31PM by novice.
GB2334556A United Kingdom
Turbojet with steam turbine
[patentimages.storage.googleapis.com]
Abstract
The Thermo Induction Turbojet operates by drawing in air and compressing it in an axial flow compressor 1. Front here it is passed into combustion chamber 6 where it is mixed with fuel from nozzles 5 and burnt. The rapidly expanding hot gases pass around convoluted water tube 10 and over encased steam turbine 3, exiting through jet nozzle 12. Water supplied from pump 8 is force circulated through water tube 10. This cools the combustion chamber and produces high pressure steam. The steam is fed via nozzles 11 to steam turbine 3, thus rapidly rotating it, the connecting shaft 2 and compressor 1. Exhausted steam exits the turbine via ducts 13 and manifold 14. From here it travels via pipe 15 to a suitable condenser in the front of the engine. Condensed water is recirculated via pump 8.
Working model of this engine was built by inventor.
[youtu.be]
US4333309A United States
Steam assisted gas turbine engine
[patentimages.storage.googleapis.com]
Abstract
A gas turbine engine is disclosed which has an integral steam power system consisting of heat absorbing boilers which convert an unpressurized liquid into an expanded and heated steam by utilizing heat normally lost through component cooling systems and the exhaust system. Upon completion of the steam power cycle, the steam is condensed back to a liquid state through a condensing system located within the compressor and other functional components of the gas turbine engine. A system of high pressure air and friction seals restrict steam or liquid condensate within designed flow bounds. The gas turbine engine disclosed is designed to give improved fuel efficiency and economy for aircraft and land use applications.
US2159758A United States
Power plant - steam assisted aircraft powerplant
[patentimages.storage.googleapis.com]
US6786036B2 United States
Bimodal fan, heat exchanger and bypass air supercharging for piston or rotary driven turbine
[patentimages.storage.googleapis.com]
Abstract
The present invention relates to turbine fan aircraft use. In particular, the present invention is directed toward a turbine fan driven by a piston or rotary (e.g., Wankel) engine. The present invention makes possible the most flexible and effective installation of a ducted fan with a fixed horsepower source, namely a conventional internal combustion engine. Effectiveness being defined as full utilization of the engine's available horsepower at the chosen flight points. In a further embodiment of the present invention, a novel heat exchanger may be provided which removes waste heat with minimal drag while boosting the fan system's effective thermal efficiency by increasing the enthalpy of the working fluid. In yet another embodiment of the present invention, bypass air from the turbine may be used to supercharge the piston or rotary engine.
Edited 1 time(s). Last edit at 09/23/2020 05:31PM by novice.
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Re: Steam turbine driven turbojet October 01, 2020 04:28PM |
German patent of early 1920s for a high speed propeller 1000 hp
steam turbine airboat with the air cooled steam condenser (Luftkondensation bei dampfbetriebenen Schnellbooten)
[worldwide.espacenet.com]
1928 Steam powered vertical takeoff helicopter/drone.
[worldwide.espacenet.com]
High speed locomotive driven by a propeller steam turbine powerplant with the air cooled steam condenser:
[worldwide.espacenet.com]
Edited 2 time(s). Last edit at 10/01/2020 04:49PM by novice.
steam turbine airboat with the air cooled steam condenser (Luftkondensation bei dampfbetriebenen Schnellbooten)
[worldwide.espacenet.com]
1928 Steam powered vertical takeoff helicopter/drone.
[worldwide.espacenet.com]
High speed locomotive driven by a propeller steam turbine powerplant with the air cooled steam condenser:
[worldwide.espacenet.com]
Edited 2 time(s). Last edit at 10/01/2020 04:49PM by novice.
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