Archive for the ‘ idea ’ Category

>Tailed blended wing body with laminar flow body and Goldschmied suction and pressure thrust

>New idea:
– A body that comprises of a laminar body and wing blended together
– There is a V-tail in a blended boom
– Rear of the center section has suction slot on top side
– The boom contains a electric fan that is used for suction and additional thrust
– There are two turbocharged Rotax 912UL engines in the wings which are hidden in blended pods that continue the airfoil shape of the wing without interruption
– Both engines turn additional turbochargers which drive generators which generate electricity for the rear fan of the aircraft

Items that need to be studied:
– does pressure thrust work with this kind of shape, or does it require axisymmetric body?
– compare the drag of minimum axisymmetric body with non-blended wings to a blended wing body which has larger cross sectional area, but potentially lower wetted area.
– wing incidence relative to the center section – center section has a lower aspect ratio than the wings and what it requires to achieve optimal lift distribution in this combined case
– the achievable gain from the lack of interference drag or very small interference drag
– optimal wing loading for a combined blended wing body compared to a pod+boom+wings solution
– shark fin shape on the outer wing sections, the gain and the issues

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Tailed blended wing body with laminar flow body and Goldschmied suction and pressure thrust

New idea:
– A body that comprises of a laminar body and wing blended together
– There is a V-tail in a blended boom
– Rear of the center section has suction slot on top side
– The boom contains a electric fan that is used for suction and additional thrust
– There are two turbocharged Rotax 912UL engines in the wings which are hidden in blended pods that continue the airfoil shape of the wing without interruption
– Both engines turn additional turbochargers which drive generators which generate electricity for the rear fan of the aircraft

Items that need to be studied:
– does pressure thrust work with this kind of shape, or does it require axisymmetric body?
– compare the drag of minimum axisymmetric body with non-blended wings to a blended wing body which has larger cross sectional area, but potentially lower wetted area.
– wing incidence relative to the center section – center section has a lower aspect ratio than the wings and what it requires to achieve optimal lift distribution in this combined case
– the achievable gain from the lack of interference drag or very small interference drag
– optimal wing loading for a combined blended wing body compared to a pod+boom+wings solution
– shark fin shape on the outer wing sections, the gain and the issues

Fuselage drag reduction principle

A major portion of aircraft drag (in addition to the wing) is generated by the fuselage. The poor aircraft has to drag the draggy fuselage forwards. It is justified to target for reducing the fuselage drag in addition to the drag of the wings to achieve high L/D ratio and thus high efficiency and exceptional miles per gallon figure.

The idea comprises of the following claims:
– a laminar body with optimal fineness ratio for minimum drag
– a tail boom behind the optimal fineness ratio laminar pod
– electric motor (or couple of electric motors in cascade) turn
one or many ducted fans that are in cascade inside the rear of the fuselage.
The fan(s) take their air intake from the boundary layer of the fuselage.
– the fans are driven with batteries on takeoff.
– the fans are driven in cruise with electricity generated from the exhaust gas of the two gasoline engines which are mounted in wings.
– there is an additional turbine mounted in the exhaust that turns a generator rather than compressing air for the gasoline engine.
– the exhaust for the air is either in the tail boom prior to the tail or after the tail, whichever is found to provide best results.
– the fans provide suction for the fuselage boundary layer and also additional thrust for the aircraft. This configuration however, does not cause additional drag for the aircraft but reduces it.
– additional generators can be mounted to wing tip vortices so that the wing tip vortex turns the turbine blades and thus generates electricity for the fans located in the rear of the fuselage.
– the generators, battery charging and fans are computer controlled.
– the fans utilize all power that can be drawn from the exhaust gas and the wing tip turbines and thus runs at full power available to it continuously. On takeoff batteries are used to ensure high centerline thrust for the hypothetical situation where one of the gasoline engines would fail.

Fuselage drag reduction principle

A major portion of aircraft drag (in addition to the wing) is generated by the fuselage. The poor aircraft has to drag the draggy fuselage forwards. It is justified to target for reducing the fuselage drag in addition to the drag of the wings to achieve high L/D ratio and thus high efficiency and exceptional miles per gallon figure.

The idea comprises of the following claims:
– a laminar body with optimal fineness ratio for minimum drag
– a tail boom behind the optimal fineness ratio laminar pod
– electric motor (or couple of electric motors in cascade) turn
one or many ducted fans that are in cascade inside the rear of the fuselage.
The fan(s) take their air intake from the boundary layer of the fuselage.
– the fans are driven with batteries on takeoff.
– the fans are driven in cruise with electricity generated from the exhaust gas of the two gasoline engines which are mounted in wings.
– there is an additional turbine mounted in the exhaust that turns a generator rather than compressing air for the gasoline engine.
– the exhaust for the air is either in the tail boom prior to the tail or after the tail, whichever is found to provide best results.
– the fans provide suction for the fuselage boundary layer and also additional thrust for the aircraft. This configuration however, does not cause additional drag for the aircraft but reduces it.
– additional generators can be mounted to wing tip vortices so that the wing tip vortex turns the turbine blades and thus generates electricity for the fans located in the rear of the fuselage.
– the generators, battery charging and fans are computer controlled.
– the fans utilize all power that can be drawn from the exhaust gas and the wing tip turbines and thus runs at full power available to it continuously. On takeoff batteries are used to ensure high centerline thrust for the hypothetical situation where one of the gasoline engines would fail.

Boom tail microlight/LSA

I was thinking which could be a suitable configuration if target would be to the microlight category (Finnish ultralight will be aligned with European microlight), or to EASA LSA category. The US-LSA category is stupid since it has some severe limitations which removes the reason to try to optimize anything – the speed limitation and also the stall speed limitation as clean -> with these limitations, it does not worth optimizing the aerodynamic performance or flap configuration, for US-LSA, the best solution probably would to design a plane, which is as lightweight as possible and which would not have any kind of flaps and which would achieve the stall speed only with the wing area (because that is what the limitation implies anyhow), so the utilized Clmax becomes close to 1.0, which is poor.

The main criteria in this more sane European category is the weight and the second main criteria is the stall speed. These are the most important features, other features are secondary. The performance can not be optimal, but it can be optimized to the constraints given by the weight and stall speed limitations. It would be also necessary to cut the part count to minimum, an inexpensive plane will be for sure more popular than the more expensive one, in the category where the buyers are not the richest people out there (who would anyhow order a Cirrus-Jet), but normal hobbyists who are not swimming in money.

So consider this:
– Plane structure would be based on carbon fiber rods (pultrusion rods).
– The fuselage would not be a structural member of the plane, but rather a baggage pod located below the spars. The twin booms would be a pultrusion rod each. The engine would be mounted to the wing spar rather than to the fuselage. These rods could have aerodynamic fairings on top of them (which also allow space for control cables etc.).
– high aspect ratio wing, which enables good climb rate with low power
– HKS700E engine in pusher configuration
– Fixed pitch pusher propeller behind the pod (but thrust line to the wing spar).
– inverted V-tail in the ends of the two booms, and the tail would connect the
two booms with the help of a pultrusion rod which functions as spar.
– Main landing gear connected to wing spar
– Nose gear located under the pod.
– Wing structure would be solid blue styrofoam, and in wing root there would be a large fairing which contains fuel (on both sides). The wing skin could be either carbon fiber or fiberglass (fiberglass to reduce cost obviously)

Think how many parts this requires compared to how many parts and layup schedules is usually needed. The pod type cockpit could be almost a complete monococue. There would be need for only instrument panel and some structure where one can assemble the pedals. Also the instrument panel, as we know it, does not need to be like it is, a panel. There are other ways arranging instruments in the plane than having a straight panel where everything is put with tiny screws. None of the modern cars use that old-fashioned way anymore. With modern avionics, you don’t need a big panel with lots of switches, knobs, circular gauges etc. You can have just two screens which display and control everything.

The only strength needed in the fuselage is for crashworthiness, it does not need to carry any loads, and it does not need to be shaped unoptimally to avoid flutter tendency for example, all structural members are straight lines and separate from the fuselage.

The idea comes from some NASA PAV concepts, but as modified. It also has some influences from the Sunseeker.

The concept could have idea of being as lightweight as possible (the lower power engine also supports this mission) and still being as highly performing as possible (that can be achieved with the light weight and aerodynamics, not so much trust is needed).

So the performance target setting for conceptual design could be:
– beat 100 hp Dynaero MCR-ULC in empty weight with large margin
– be on par with 100 hp Dynaero MCR-ULC in speed (with only 60% of the power available)
– and the rest comes from the category limitations
– be a lot cheaper than most other same category plane on the market
– climb rate 800 fpm (remember that because of the low climb speed, the climb gradient is high despite of the not so high number compared to high performance aircraft)

Compromise:
– beat 100 hp Dynaero MCR-ULC in empty weight
– cruise speed compromised to between 80 hp WT9 Dynamic and 80 hp MCR.
– climb rate 600 fpm

Failure:
– heavier than MCR-ULC
– slower than 100 kts in cruise
– climb rate less than 500 fpm

Anyone interested in a such thing or having ideas (for or against) for a such thing?

Here is an illustration about the idea (15 minutes of Rhino magic):

Boom tail microlight/LSA

I was thinking which could be a suitable configuration if target would be to the microlight category (Finnish ultralight will be aligned with European microlight), or to EASA LSA category. The US-LSA category is stupid since it has some severe limitations which removes the reason to try to optimize anything – the speed limitation and also the stall speed limitation as clean -> with these limitations, it does not worth optimizing the aerodynamic performance or flap configuration, for US-LSA, the best solution probably would to design a plane, which is as lightweight as possible and which would not have any kind of flaps and which would achieve the stall speed only with the wing area (because that is what the limitation implies anyhow), so the utilized Clmax becomes close to 1.0, which is poor.

The main criteria in this more sane European category is the weight and the second main criteria is the stall speed. These are the most important features, other features are secondary. The performance can not be optimal, but it can be optimized to the constraints given by the weight and stall speed limitations. It would be also necessary to cut the part count to minimum, an inexpensive plane will be for sure more popular than the more expensive one, in the category where the buyers are not the richest people out there (who would anyhow order a Cirrus-Jet), but normal hobbyists who are not swimming in money.

So consider this:
– Plane structure would be based on carbon fiber rods (pultrusion rods).
– The fuselage would not be a structural member of the plane, but rather a baggage pod located below the spars. The twin booms would be a pultrusion rod each. The engine would be mounted to the wing spar rather than to the fuselage. These rods could have aerodynamic fairings on top of them (which also allow space for control cables etc.).
– high aspect ratio wing, which enables good climb rate with low power
– HKS700E engine in pusher configuration
– Fixed pitch pusher propeller behind the pod (but thrust line to the wing spar).
– inverted V-tail in the ends of the two booms, and the tail would connect the
two booms with the help of a pultrusion rod which functions as spar.
– Main landing gear connected to wing spar
– Nose gear located under the pod.
– Wing structure would be solid blue styrofoam, and in wing root there would be a large fairing which contains fuel (on both sides). The wing skin could be either carbon fiber or fiberglass (fiberglass to reduce cost obviously)

Think how many parts this requires compared to how many parts and layup schedules is usually needed. The pod type cockpit could be almost a complete monococue. There would be need for only instrument panel and some structure where one can assemble the pedals. Also the instrument panel, as we know it, does not need to be like it is, a panel. There are other ways arranging instruments in the plane than having a straight panel where everything is put with tiny screws. None of the modern cars use that old-fashioned way anymore. With modern avionics, you don’t need a big panel with lots of switches, knobs, circular gauges etc. You can have just two screens which display and control everything.

The only strength needed in the fuselage is for crashworthiness, it does not need to carry any loads, and it does not need to be shaped unoptimally to avoid flutter tendency for example, all structural members are straight lines and separate from the fuselage.

The idea comes from some NASA PAV concepts, but as modified. It also has some influences from the Sunseeker.

The concept could have idea of being as lightweight as possible (the lower power engine also supports this mission) and still being as highly performing as possible (that can be achieved with the light weight and aerodynamics, not so much trust is needed).

So the performance target setting for conceptual design could be:
– beat 100 hp Dynaero MCR-ULC in empty weight with large margin
– be on par with 100 hp Dynaero MCR-ULC in speed (with only 60% of the power available)
– and the rest comes from the category limitations
– be a lot cheaper than most other same category plane on the market
– climb rate 800 fpm (remember that because of the low climb speed, the climb gradient is high despite of the not so high number compared to high performance aircraft)

Compromise:
– beat 100 hp Dynaero MCR-ULC in empty weight
– cruise speed compromised to between 80 hp WT9 Dynamic and 80 hp MCR.
– climb rate 600 fpm

Failure:
– heavier than MCR-ULC
– slower than 100 kts in cruise
– climb rate less than 500 fpm

Anyone interested in a such thing or having ideas (for or against) for a such thing?

Here is an illustration about the idea (15 minutes of Rhino magic):

>Podrel

>A funny idea came into my mind. There are couple of Petrel Amphibians in Finland. It looks like a plane of Donald Duck.

Here is one discussion thread in Finnish about it:
Nyt on suomen kolmas akuankkakone valmis

It has staggered wings (two wings, one on top of each other). What if it was completely different. Not exactly completely, but quite completely. Now on this latest Super Petrel, the engine pod is integrated to the upper wing. How if the upper wing was the only wing on the plane, the lower wing would not exist, the upper wing would be twice as long. The tail would not be angled upwards from the bottom of the fuselage, but it would be rather connected with two booms to the wing, in similar manner than it has been done on Adam A500. And finally, but not least, what if the fuselage was not a traditional fuselage, but a pod in the end of a strut, that fits the occupants, and nothing more. It would end before the prop arc. This would allow moving the propeller a bit downwards.

So the result:
– no aerodynamic penalty normally associated with the amphibian planes.
– center of thrust is at the same level as is the lift (high wing)
– because of the boom tail, the tail does not hit the water unless the plane flips.
– because you would not need to fit the tail to the fuselage, the fuselage-pod could be made a better boat shape

I could not resist, but name this idea as Podrel. Actually this is not a new idea entirely, it is partially borrowed from a NASA tech paper, but the application to amphibian use could be new twist for the configuration.

What do you think about this?