Date   

Re: Aerodynamics: Airfoil Camber, Flaps, Slots-Slats & Drag: "Smoke Lifts" c...

Jay Scheevel
 

You are absolutely right Gary. Here is the model that I made of the whole configuration (including the "slot"). The tricky part is that these models do not accurately model the separation bubble from a stalled canard. The effect of separation is to rapidly increase the relative wind to the wing (putting it closer to stall) and to vector turbulent air under the wing in the vicinity of the leading edge of the main wing. Neither condition is good. Thanks for your experiential knowledge.

Cheers,
Jay


Re: Aerodynamics: Airfoil Camber, Flaps, Slots-Slats & Drag: "Smoke Lifts" c...

Gary McKirdy
 

Pat and Jay,
Jay's Third picture,
For anyone following this if that 3rd picture could happen you would lose main (rear) wing lift to the extent that the Q would over rotate into a tail slide.
1. The Eppler rear wing section was specifically chosen to prevent this. It is higher drag  than it needs to be as a consequence but its a very good trade off, trust me!
2. I am not aware of this rear wing stall ever causing a Q to crash. Please correct me if you know better.
3. I could only ever get close to rear wing stall by full aileron deflection at well aft C of G, so rolling violently left and right. 

Yes, during deliberate test flying I once felt it start to go tail down quick and recovered immediately by forward stick and was ready to add forward reflexor which in my case proved to be unnecessary.
In contrast I did 70hrs in a European built Rutan Defiant push/pull. Not tandem but canard 4/5 seat long Eze twin engine 320hp. That felt worse inside C of G envelope! 
It eventually went to Texas where it's new owner "filled her up". He then made 3 more fatal mistakes,  first 2 warned of in the POH by Burton Rutan!
1. Took off with side hinged canopy unlocked which once open couldn't be closed from P1 side whilst strapped in.(destroyed lift only on rear wing and strakes). Read nose up.
2. Didn't have a front seat passenger.(Aft end of COF G range. Read more nose up.
3. Throttled front engine back at a "safe height". Read more nose up.
IMHO Downthrust on front engine was only thing keeping it flying.
Once throttle closed to stop prop blast it entered a flat stall of Mainwing and canard and fell 700 ft from pattern height with nose barely dropping. Crashed and burnt completely. 
That was very sobering especially when I found out he was a brain surgeon from Lubbock!
Fly safe.
Gary


On Thu, 3 Jan 2019 16:35 Gary McKirdy, <gary.mckirdy21@...> wrote:
Hi Jay, 
Thanks for that. 
One thing to remember though, that Mainwing isn't represented in the canard smoke trail is it?
The Q benefits from the effective slot between main wing and canard enormously at high angles of attack.
The biggest benefit of the tandem wing arrangement however is the effective unwinding of the tip vortices between canard and rear wing.
I once flew mine at ridiculous aft C OF G when overloaded.
What I discovered to my utter amazement was that it not only flew faster, it climbed faster and by a significant amount.
The downside is loss of pitch stability meaning it has to be flown hands on as stick release will cause an accelerating diversion in pitch up or down.
From an induced drag minimization perspective the ideal is 50/50 weight distribution on canard and Mainwing. 
This is well outside the safe design envelope so don't be tempted to repeat what I did.
With knowledge and understanding and too much youth and curiosity I proved to myself all this to be the case.  
So nobody else needs to. Unless you have extremely fast reactions and/or a ballistic recovery chute.
The future of minimal aircraft parasite and induced drag lies in the tandem wing design. Great for minimum fuel requirement so electrification:)

Gary

On Thu, 3 Jan 2019 16:19 jay@... [Q-LIST], <Q-LIST@...> wrote:
 

A few years back, I ove-rposted some snaps from that same video on my Q2 canard to get an idea of the geometry of generalized airflow on it. Gary, you may like this three snap sequence.

Cheers,
Jay


Re: Aerodynamics: Airfoil Camber, Flaps, Slots-Slats & Drag: "Smoke Lifts" c...

Jay Scheevel
 

You are absolutely right Gary. Here is the model that I made of the whole configuration (including the "slot"). The tricky part is that these models do not accurately model the separation bubble from a stalled canard. The effect of separation is to rapidly increase the relative wind to the wing (putting it closer to stall) and to vector turbulent air under the wing in the vicinity of the leading edge of the main wing. Neither condition is good. Thanks for your experiential knowledge.

Cheers,
Jay


Re: Aerodynamics: Airfoil Camber, Flaps, Slots-Slats & Drag: "Smoke Lifts" c...

Jay Scheevel
 

Just an estimate, Pat. My modeling shows that there is also influence of the flow due to the presence or absence of the rear wing, so this is really just a cartoon, but keep in mind that the air between the two lines is turbulent, so lacking the conditions nescessary for proper flow over the rear wing. A region of flight best avoided, so caution against accellerated pitch changes in this configuration.

Cheers,
Jay


Re: Aerodynamics: Airfoil Camber, Flaps, Slots-Slats & Drag: "Smoke Lifts" c...

Gary McKirdy
 

Hi Jay, 
Thanks for that. 
One thing to remember though, that Mainwing isn't represented in the canard smoke trail is it?
The Q benefits from the effective slot between main wing and canard enormously at high angles of attack.
The biggest benefit of the tandem wing arrangement however is the effective unwinding of the tip vortices between canard and rear wing.
I once flew mine at ridiculous aft C OF G when overloaded.
What I discovered to my utter amazement was that it not only flew faster, it climbed faster and by a significant amount.
The downside is loss of pitch stability meaning it has to be flown hands on as stick release will cause an accelerating diversion in pitch up or down.
From an induced drag minimization perspective the ideal is 50/50 weight distribution on canard and Mainwing. 
This is well outside the safe design envelope so don't be tempted to repeat what I did.
With knowledge and understanding and too much youth and curiosity I proved to myself all this to be the case.  
So nobody else needs to. Unless you have extremely fast reactions and/or a ballistic recovery chute.
The future of minimal aircraft parasite and induced drag lies in the tandem wing design. Great for minimum fuel requirement so electrification:)

Gary

On Thu, 3 Jan 2019 16:19 jay@... [Q-LIST], <Q-LIST@...> wrote:
 

A few years back, I ove-rposted some snaps from that same video on my Q2 canard to get an idea of the geometry of generalized airflow on it. Gary, you may like this three snap sequence.

Cheers,
Jay


Re: Aerodynamics: Airfoil Camber, Flaps, Slots-Slats & Drag: "Smoke Lifts" c...

Patrick Panzera
 

Jay,

On that third photo, how did you determine that the upper dashed red line would go over the top of the wing?
The smoke lines above the canard show a trajectory of under the wing, even if you don't factor the tendency of the upper and lower smoke lines converging. 

Pat



On Thu, Jan 3, 2019 at 8:18 AM jay@... [Q-LIST] <Q-LIST@...> wrote:
 

A few years back, I ove-rposted some snaps from that same video on my Q2 canard to get an idea of the geometry of generalized airflow on it. Gary, you may like this three snap sequence.

Cheers,
Jay


Re: Aerodynamics: Airfoil Camber, Flaps, Slots-Slats & Drag: "Smoke Lifts" c...

Jay Scheevel
 

A few years back, I ove-rposted some snaps from that same video on my Q2 canard to get an idea of the geometry of generalized airflow on it. Gary, you may like this three snap sequence.

Cheers,
Jay


Re: Aerodynamics: Airfoil Camber, Flaps, Slots-Slats & Drag: "Smoke Lifts" c...

Gary McKirdy
 

That's great. Analogue beats digital for me!


On Wed, 2 Jan 2019 20:41 Charlie oneskydog@... [Q-LIST], <Q-LIST@...> wrote:
 

History lesson visuals of air around your wing and canard. Caution dated music!

One Sky Dog

https://youtu.be/q_eMQvDoDWk



Re: Flight Report

Jay Scheevel
 

Hi Bruce,

I have a thermostatically controlled oil cooler adapter. It is fully open to the cooler at 190F. Oil flow goes from pump through filter, through cooler to gallery. The pressure sensor is on the gallery and pressures are mid-range of the recommended, so I know I have flow through the cooler. the oil cooler has a dedicated scoop (actually the induction air intake for on the O-200 cowl). The cooler flow is isolated from the airflow over the cylinder barrels. The coolant system (left and right independent) also have their own dedicated scoop and ducts that are isolated from the flow over the cylinder barrels. Each side has its own exit air flap that is adjustable from the cockpit. If I need more oil cooling after the engine is broken in, I have the option of installing heat exchangers that will run off of the coolant circuit. Those are very efficient. Will see about that. Right now, I am letting the temps work their way down to an equilibrium. The oil cooler is off of one side of a Cessna 310, has been reconditioned, so it should be sufficient.

Cheers,
Jay


Re: Flight Report

Jay Scheevel
 

Hi Matthew,

Yes I am concerned about summer time, but right now I do not think OAT is the primary factor. I will continue to watch the progression as Oil Temps decrease with each flight. Will assess, come springtime. We don't get to 80 until about June, so I should have time to make any changes. Just glad I waited til winter to start testing.

Cheers,
Jay


Re: Flight Report

Jay Scheevel
 

Hi Bruce,

I have a thermostatically controlled oil cooler adapter. It is fully open to the cooler at 190F. Oil flow goes from pump through filter, through cooler to gallery. The pressure sensor is on the gallery and pressures are mid-range of the recommended, so I know I have flow through the cooler. the oil cooler has a dedicated scoop (actually the induction air intake for on the O-200 cowl). The cooler flow is isolated from the airflow over the cylinder barrels. The coolant system (left and right independent) also have their own dedicated scoop and ducts that are isolated from the flow over the cylinder barrels. Each side has its own exit air flap that is adjustable from the cockpit. If I need more oil cooling after the engine is broken in, I have the option of installing heat exchangers that will run off of the coolant circuit. Those are very efficient. Will see about that. Right now, I am letting the temps work their way down to an equilibrium. The oil cooler is off of one side of a Cessna 310, has been reconditioned, so it should be sufficient.

Cheers,
Jay


Re: Looking for Early Lightspeed AEI 42 Documentation

Michel Royer
 

Hi Robert.... 
Maybe your lucky day, I had one installed on a Zenith CH-300 and decided
to go dual P-Mag last summer. The system was still working great but I wanted to replace
my old mechanical mag and once I did that I wasn't totally happy with the LSE and P-Mag combo
so that is when I removed the LSE for a second P-Mag..

I have the installation/operation manual and some Bulletin from the stone age and
exchange communications with Klaus...

Michel .


Re: Happy New Year

Dan Thomas
 

Received crystal clear Sam.  Congrats on your 2019 first day flight.       --Dan Thomas,  Everett, WA




On Wednesday, January 2, 2019, 10:36:00 AM PST, sam.hoskins@... [Q-LIST] wrote:


 

This is a test. Is Yahoo still working?


Aerodynamics: Airfoil Camber, Flaps, Slots-Slats & Drag: "Smoke Lifts" c...

One Sky Dog
 

History lesson visuals of air around your wing and canard. Caution dated music!

One Sky Dog


https://youtu.be/q_eMQvDoDWk


Q-artwork!

Jay Scheevel
 

Hi All,

 

I was reviewing my test flights so far on Google Earth. Thought it made some nice artwork. The yellow track to the left side is the one that went up to 12000+ MSL. Having too much fun, Bruce!

 

Happy New Year to all! (too cold and snowy to fly out here now). Where is your flight report, Mike?

 

Cheers,

Jay Scheevel, N8WQ


Happy New Year

Sam Hoskins
 

This is a test. Is Yahoo still working?


Aerodynamics: Airfoil Camber, Flaps, Slots-Slats & Drag: "Smoke Lifts" c...

One Sky Dog
 

History lesson visuals of air around your wing and canard. Caution dated music!

One Sky Dog


https://youtu.be/q_eMQvDoDWk


Re: Flight Report

Jim Patillo
 

Test


Re: Flight Report - 2019

Jim Patillo
 

Forgive me if this posts more than once, Yahoo is acting weird for me.

I made my first flight of the year this morning at 10:00 am to beautiful blue Northern California skies. Temp 46F, Wind 350@15K, takeoff Runway 7 @ KLVK. A great way to start 2019.

Jim Patillo
N46JP - Q200


Re: Flight Report

Bruce Crain
 

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