Rotor revolution

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Martin W

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Try to keep the rotor working at low speed.
.

--- Even a rigid rotor is not rigid
--- Tie a rope to the ends of helicopter blades and lift up
--- The helicopter will stay on the ground and the blades will bend up like a big U
--- Centrifugal force is what keeps blades straight
--- Tie a rock to a string and spin it around ... string will be straight ... same thing
--- Most helicopter blades turn about 300 rpm to keep them straight
--- Less than 200 rpm they will bend and you will fall to the ground.

--- Want to go faster than 200 mph ... use an airplane
--- Want to go straight up .... use a helicopter ... but they fly less than 200 mph
--- There is no magic invention to change it.

.
 

dong090909

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.

--- Even a rigid rotor is not rigid
--- Tie a rope to the ends of helicopter blades and lift up
--- The helicopter will stay on the ground and the blades will bend up like a big U
--- Centrifugal force is what keeps blades straight
--- Tie a rock to a string and spin it around ... string will be straight ... same thing
--- Most helicopter blades turn about 300 rpm to keep them straight
--- Less than 200 rpm they will bend and you will fall to the ground.

--- Want to go faster than 200 mph ... use an airplane
--- Want to go straight up .... use a helicopter ... but they fly less than 200 mph
--- There is no magic invention to change it.

.
I understand that rigid rotors also bend
I will continue to evaluate its level and ask you for advice to facilitate subsequent improvements.
And I believe it is indeed a big improvement over traditional flexible rotors
Also, my planned low speed is well below 200km, only about 60km,
thanks.
 

Martin W

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I understand that rigid rotors also bend
I will continue to evaluate its level and ask you for advice to facilitate subsequent improvements.
And I believe it is indeed a big improvement over traditional flexible rotors
Also, my planned low speed is well below 200km, only about 60km,
thanks.

I understand the slow speed helicopter part .... but to convert to a high speed airplane using wings .... how do you slow your rotor .... and stop your rotor ... and fold your rotor .... without the blades bending ????

Cannot be done.
.
 

dong090909

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I understand the slow speed helicopter part .... but to convert to a high speed airplane using wings .... how do you slow your rotor .... and stop your rotor ... and fold your rotor .... without the blades bending ????

Cannot be done.
.
Simple version, the flight speed is only 60 kilometers, similar to Russia, An-2
When landing, lift is provided from the fixed wing to the rotor, which is a process similar to that mentioned in some professional books: Lift Corridor
High-speed version, the speed needs to be reduced as much as possible in the fixed-wing working state: such as: the aircraft climbs, then glides
 

dong090909

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Hello Dong,

models often do not justice to the (final) idea - as your design is at this moment - it is "overwhelming" to me.
Obviously your descriptions are "affected" by a less than perfect translator (...another fantastic field for endless improvements!) so some concepts might just not be understandable to us - as mentioned above - a few sketches would likely help us a lot to understand your ideas.

Now - no doubt your design is VERY complex - lots of moving parts, lots of different systems!

I do like Elon Musk's engineering philosophy:

- A Simplify! Take away everything you do not need! To the extreme point where you take away too much!
- B Do not be afraid to put stuff back in!
- C Fault of most excellent engineers: Perfecting a unnecessary part/system!! See A
- D Repeat A and B until nothing "moves" anymore!

To me it seems you try to accomplish a machine that can do everything - do you really need such a machine?

As it is, most machines today are somewhat specialized (any machine, not just helicopters!).
Most universal machines give up some performance in all areas - The V-22 Osprey is one example!
However it seems all the compromises still allow it to perform as desired by the designers...

As your design goes at this point - you need to start to shed complexity and define priorities! IF your goal is fast point to point, hover performance isn't your priority and can be compensated by increased power for short times.
IF hover performance is your primary concern - you cannot have wings.....

So - at some point you need to define the purpose of your design!
[Unless you just see it as a design/calculation exercise! But if I am not mistaken you are looking towards a patent....]

Your mention of UFOs: As far as I understand - most saucer-like UFOs are NOT saucer shaped for aerodynamic reasons, rather for supposed engine design purposes. The supposedly observed flight performances and maneuvers of these machines would indicate that their propulsion and maneuverability has nothing to do with aerodynamics at all - rather force-field control. Be it magnetic, gravity-control, particle attraction/repulsion, etc... (mostly still fiction on this planet!)

Also - history already shows where your compromises will likely be:
- The Osprey tilts the rotors and uses them for forward propulsion, but lacks performance in hover (the compromise: shorter rotors are less efficient, but still are able to work as propellers), and so far it is in a class by itself, going 300kts +
- Sikorsky x2 is betting on stiff rotors and a pusher prop - 250kts
- Eurocopter (now Airbus Helicopters), X3 - 253kts, is moving the tailrotor to the sides (forward facing propellers, for forward propulsion in airplane mode and differential propulsion in helicopter mode), also slowing down the main-rotor to the minimum stable rotor-speed and neutralizing it to zero lift which then neutralizes retreating blade stall effects.
Propellers (torque control and forward propulsion) are mounted on high-speed wings, that do not fly below 80 kts, I wonder if they could have made them even faster - likely a commercial application will stall higher, as 80kts is certainly no problem for the rotor...
[Have a close look at these machines! Look at all the moving parts on a Osprey, on the Sikorsky, on the Eurocopter and see where their speed limits and hover performance ends up.]

DIRECT suggestions from operational experience:

- get rid of blade folding/sweeping in flight! the forward speed needed for wing born flight will be a huge problem for folding rotors in flight - either they will tend to flap up or down or be heavy because of the required stiffness
- get rid of the lower rotor! It WILL get damaged nearly immediately by anything on the ground!

At present you are trying to make the theoretically perfect machine - theory is always perfect - however, real world application has to be functional! So - maybe you are not at the point yet, but eventually you need to adjust your design to become functional - then at least as functional as your existing competitors - then you need adjust it even more to become more functional than your competitors!

Good Luck!!
1. First of all, I am very sorry to reply you so late.
2. Because a few days ago, when I saw your point of view, I didn't think my answer was clear at once.
3. Now, I can finally have time to sort out my thoughts and communicate with you:
4. Your core problem is: hovering and speed (or fixed wing) are incompatible, and a trade-off is required
My take is:
A. If the rotor can be collected, then your core problem can be solved. There is no need to consider trade-offs.
B. Of course, it brings new problems: in history, many people have said that the rotor cannot be collected
C. My solution is:
---The flexible rotor is too complicated to be collected; the rigid rotor brings hope;
---Put the rotor up and down the fuselage for easy collection;

5. Your second question is: My structure is too complex
My explanation is: this institution is mainly composed of:
A. Light, labor-saving and strong enough diamond jack, the link mechanism is the core;
B. Auxiliary is: slide bar power supply and drive motor

thanks
 

TFF

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At 60 km, either wings or rotors work really well. Those are easy ranges for both to work. How is having both going to help?
 

AeroER

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dong090909

Have you spent any time studying the Canard Rotorwing concept of operation?

A rotary wing - fixed wing hybrid aeroplane can't be much simpler than a successful CRW type vehicle with the bugs worked out.

Its strength might not be vertical takeoff and landing, but STOL operation,especially with a load.
 

dong090909

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At 60 km, either wings or rotors work really well. Those are easy ranges for both to work. How is having both going to help?
After the realization, it means that the principle of the aircraft with the stowable rotor is correct, and then it is gradually improved
 

dong090909

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1. I'm sorry, I will shame all mankind together
2. Yes, I will improve the sample:
A. Still without any remote control, the only reason is the cost.
B. I only assemble the keys on the PCB and hide all the wires inside the paper tube
3. Then, walk into as many air shows as I can get to.
4. And in this state, it is sold worldwide.

Dead together, even I dead, I must understand the truth
 

Vigilant1

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Dong090909,
An idea for your consideration (since we are brainstorming a lot of probably impractical ideas in hopes of finding a good one):
You want vertical takeoff, you prefer simple rotors, probably coaxial counter-rotating ones. You'd like to stow the rotors and use a regular wing for efficient conventional flight at relatively high speed.
How about this (sorry, no picture):
1) General: Use a conventional tubular fuselage with the wing on top. The mast for the coaxial rotors (4 blades each) comes out of the fuselage top, at about the 35% chord point of the wings (close to where the CG of the plane should be). In VTOL mode, the rotors provide lift. In horizontal "cruising flight" mode, lift is provided by the (thick) conventional wing and the rotor mast telescopes down, the rotor blades are indexed to align with the fuselage and the wing (that's why each hub can have only 4 blades). In forward flight the wings remain stored there.
Propulsion for cruise flight comes from propellers in the nose and tail (more below).
2) Flight control:
Vertical flight: Maybe you can get away with just a collective and no cyclic on the main rotors. Roll control: Very large control surfaces on the wings (LARGE ailerons in horiz flight) operate in vertical flight to provide roll control. Roll right by deflecting the left aileron down (up to 90 deg), the higher rotor downwash pressure on the (still up) right aileron causes a right roll. Yaw and pitch control are provided by vanes placed in the flow path of the propellers in the nose and tail. The vanes are on the fuselage behind the nose prop and also on the fuselage in front of the tail prop. During vertical flight at low speed, the tail prop blades would be pitched to blow air forward over vanes placed on the fuselage (so that it would be possible to also perform translational left, right, forward and backward movement over the ground (or over a fixed spot over the ground during windy conditions) while also controlling yaw and pitch). As forward speed increases (propulsion by the forward propeller initially), the rear prop vane control is less important and the rear prop can gradually be pitched for forward propulsion (as a conventional pusher prop).
Horizontal flight control: Roll is controlled by wing ailerons. Pitch and yaw are controlled by the vanes at the nose and tail.
The coordination of the vanes and ailerons would be fly-by-wire control to achieve the desired result commanded by the pilot (who is using conventional aircraft controls-- stick rudder pedals, throttle).
Exercises left to the student:
1) After they've stopped turning and before they are stowed, how to keep the rotor blades in proper alignment (i.e. not snaking around in the airflow, especially the ones pointed forward) when there's enough airspeed to allow the craft to fly conventionally. Maybe the corresponding top and bottom blades get pinned together for more rigidity?
2) Flight control during transition from vertical to horizontal to vertical. Computers will be needed.

There's nothing new under the sun I'm sure this idea has been proposed elsewhere. Maybe I even saw it as a kid in an episode of Thunderbirds.

If you like it I would guess the challenges of implementing it would be significant and occupy you for a long time.

Mark
 
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dong090909

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Messages
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GuangDong China
Dong090909,
An idea for your consideration (since we are brainstorming a lot of probably impractical ideas in hopes of finding a good one):
You want vertical takeoff, you prefer simple rotors, probably coaxial counter-rotating ones. You'd like to stow the rotors and use a regular wing for efficient conventional flight at relatively high speed.
How about this (sorry, no picture):
1) General: Use a conventional tubular fuselage with the wing on top. The mast for the coaxial rotors (4 blades each) comes out of the fuselage top, at about the 35% chord point of the wings (close to where the CG of the plane should be). In VTOL mode, the rotors provide lift. In horizontal "cruising flight" mode, lift is provided by the (thick) conventional wing and the rotor mast telescopes down, the rotor blades are indexed to align with the fuselage and the wing (that's why each hub can have only 4 blades). In forward flight the wings remain stored there.
Propulsion for cruise flight comes from propellers in the nose and tail (more below).
2) Flight control:
Vertical flight: Maybe you can get away with just a collective and no cyclic on the main rotors. Roll control: Very large control surfaces on the wings (LARGE ailerons in horiz flight) operate in vertical flight to provide roll control. Roll right by deflecting the left aileron down (up to 90 deg), the higher rotor downwash pressure on the (still up) right aileron causes a right roll. Yaw and pitch control are provided by vanes placed in the flow path of the propellers in the nose and tail. The vanes are on the fuselage behind the nose prop and also on the fuselage in front of the tail prop. During vertical flight at low speed, the tail prop blades would be pitched to blow air forward over vanes placed on the fuselage (so that it would be possible to also perform translational left, right, forward and backward movement over the ground (or over a fixed spot over the ground during windy conditions) while also controlling yaw and pitch). As forward speed increases (propulsion by the forward propeller initially), the rear prop vane control is less important and the rear prop can gradually be pitched for forward propulsion (as a conventional pusher prop).
Horizontal flight control: Roll is controlled by wing ailerons. Pitch and yaw are controlled by the vanes at the nose and tail.
The coordination of the vanes and ailerons would be fly-by-wire control to achieve the desired result commanded by the pilot (who is using conventional aircraft controls-- stick rudder pedals, throttle).
Exercises left to the student:
1) After they've stopped turning and before they are stowed, how to keep the rotor blades in proper alignment (i.e. not snaking around in the airflow, especially the ones pointed forward) when there's enough airspeed to allow the craft to fly conventionally. Maybe the corresponding top and bottom blades get pinned together for more rigidity?
2) Flight control during transition from vertical to horizontal to vertical. Computers will be needed.

There's nothing new under the sun I'm sure this idea has been proposed elsewhere. Maybe I even saw it as a kid in an episode of Thunderbirds.

If you like it I would guess the challenges of implementing it would be significant and occupy you for a long time.

Mark
If you do see similar schemes, please provide information. Otherwise, it will be:
In the history of human aviation, so far, the Chinese are the only truly invented aircraft that have not been questioned by the world for plagiarism.

Since you don't have any pictures, it's hard for me to really grasp your train of thought.

For telescopic shafts, it has been considered a few years ago,
In the beginning, I use the simplest for the time being.

I'm pretty sure about computer controls and sensors.
Ten years ago, it was because I developed: a DIY portable computer using any desktop motherboard, and promoted its application in the aircraft, which officially prompted me to develop this aircraft.
 

TFF

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D Hillberg

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very low low low earth orbit
If you do see similar schemes, please provide information. Otherwise, it will be:
In the history of human aviation, so far, the Chinese are the only truly invented aircraft that have not been questioned by the world for plagiarism.

Since you don't have any pictures, it's hard for me to really grasp your train of thought.

For telescopic shafts, it has been considered a few years ago,
In the beginning, I use the simplest for the time being.

I'm pretty sure about computer controls and sensors.
Ten years ago, it was because I developed: a DIY portable computer using any desktop motherboard, and promoted its application in the aircraft, which officially prompted me to develop this aircraft.

China has many under license helicopters - Mostly French & Russian design - Your larger Z 8 helicopter was a French Frelone airframe that started life as a Sikorsky Mojave - Z 20 sure looks like a Sikorsky H 60 [Regan sent 20 S-70's to the PRC late 80s]
f8b262a0150d47259bff3480a12c9d4e.jpg

Super Freloen - = Z-8 rotor system is old Sikorsky Mojave - US = Westminster - England = - Frelone -French = Z 8 - China

harbin-z20-multimission-medium-transport-helicopter-china_3.jpg

Z 20 A clone of the Sikorsky H 60, Notice the 5 bladed rotor system [French meets Xerox]

You need to study more and gabb less. You can only buy so much before what you don't know catches up with you. :popcorn:

China and Pratt & Whitney Canada were caught using civilian power plants on military articles big fines laid out by the International community.

My wifes uncle is an Air Force General in Xian. I do enjoy my visits there, See all the neat stuff too.
Chu CJC-3
Quiz: Who's this design, when?
 
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dong090909

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Joined
Oct 25, 2016
Messages
101
Location
GuangDong China
China has many under license helicopters - Mostly French & Russian design - Your larger Z 8 helicopter was a French Frelone airframe that started life as a Sikorsky Mojave - Z 20 sure looks like a Sikorsky H 60 [Regan sent 20 S-70's to the PRC late 80s]
f8b262a0150d47259bff3480a12c9d4e.jpg

Super Freloen - = Z-8 rotor system is old Sikorsky Mojave - US = Westminster - England = - Frelone -French = Z 8 - China

harbin-z20-multimission-medium-transport-helicopter-china_3.jpg

Z 20 A clone of the Sikorsky H 60, Notice the 5 bladed rotor system [French meets Xerox]

You need to study more and gabb less. You can only buy so much before what you don't know catches up with you. :popcorn:

China and Pratt & Whitney Canada were caught using civilian power plants on military articles big fines laid out by the International community.

My wifes uncle is an Air Force General in Xian. I do enjoy my visits there, See all the neat stuff too.
Chu CJC-3
Quiz: Who's this design, when?
I know it's Chinese, but I am not sure whether it's the first of its kind
 
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