Topics

Sparrow strainer stall

One Sky Dog
 

Bruce,

I found your previous description of stalling the sparrow strainers.

What is the angle between the lower elevator surface and the bottom of the sparrow strainer airfoil?

On Mar 19, 2020, at 7:39 PM, Bruce Crain <jcrain2@...> wrote:


Thanks David, 
For a moment I thought it gave me a bit faster airspeed but the I realized that the air was pretty turbulent and I was having a hard time trimming for straight and level.  I do know that someone said "if you trim the elevator up and compensate level cruise trim with the reflexor you get more airspeed.  I cannot confirm that was the case.  And yes the zig zag did work.  Just made the airplane ride nose high for cruise.
 
Bruce

---------- Original Message ----------
From: "David J. Gall" <David@...>
To: main@q-list.groups.io
Subject: Re: [Q-List] Sparrow strainer stall
Date: Thu, 19 Mar 2020 12:10:51 -0700

Bruce,
 
I don’t think the zig-zag tape “created drag” the way you describe it. To me, your description seems like the tape was doing exactly what it was supposed to be doing: keeping the airflow energized and attached. The fact that the now-attached airflow made the elevator “ride up” is exactly what one would expect from an improvement in the air flow over the top of the airfoil; instead of matching the new elevator position with reflexor, you could have accepted the “new normal” and trimmed for it. My bet is that you’ll see similar or identical results with VGs. Was the airplane slower as a result? If so, perhaps that was caused by the nose-high attitude you created when you trimmed the reflexor TE up instead of elevator TE down, and not by “added drag” from the zig-zag tape.
 
The problem with the sparrow strainer being stalled is that the little beastie is too small and/or too close to the elevator hinge line. This could be fixed in any of several ways, including making it bigger or re-contouring the elevator. 
 
I wouldn’t count the zig-zag tape as a failure — according to your description, it was eminently successful!
 
David J. Gall

On Mar 18, 2020, at 6:25 PM, Bruce Crain <jcrain2@...> wrote:

Jon, 
I tried the zig zag tape and did get the stall to go away right up the last test where I finally had all of the zig zag cleaned off.  With the zig zag the stall would not happen on the strainer but it created drag and dragged the strainer up and thus the elevator also.  The elevator would ride up a half inch or so and stay and I would reflex the ailerons up to compensate.
 
I am going to test actual vortex generators next.  Trying to make them small enough so that they don't  create drag and pull the elevator up.  So the zig zag did work but with less than great results for the trim I am used to seeing.
 
Before the next tests I am pulling a cylinder to check for a leak around a cylinder base stud or cylinder base o ring perhaps.
 
Bruce Crain


---------- Original Message ----------
From: "Jon Finley" <jd@...>
To: main@Q-List.groups.io
Subject: Re: [Q-List] Sparrow strainer stall
Date: Wed, 18 Mar 2020 11:41:07 -0700

Howdy Jay,

I recently heard a woman admit that there are "degrees of yes" - I was stunned. Of course, I was very familiar with this phenomena but had never heard the other gender actually admit to it. Now you are talking about "degrees of stalled" - please confirm your gender!! 

:-)

Seriously, I know you are correct. I also saw this in my GU canard tuft testing (moving up/forward on the airfoil). 

Bruce; I don't know what to say on your strainers. I struggled to know how to set them (and eventually gave up on them on my GU, since they weren't needed/per-plans (instead, springs take up the load, as I recall)).  I imagine you have already tried reducing their angle of attack - and noted some change in stick force?? 

Jon  

 

Jay Scheevel
 

Hi Bruce,

 

If the tufts are pointing any direction other than straight back, they are caught up in the vortex within the separation bubble. The size of this bubble increases dependent on the airflow conditions. Could be that when you are in cruise the bubble is small and then when you see the “stalled strainer”, the bubble has become large enough to include the sparrow strainer.  I have superimposed some wind tunnel smoke trail snapshots on my canard at three different attack angles, so you can see the size of the bubble (where the smoke trails get jumbled). The tubuelence always there to some extent because of the pressure discontinuity at the trailing edge. The only time it goes away is on a symmetrical airfoil at zero incidence. The square edge on the trailing edge of the LS1 is an attempt to limit the size of that turbulence bubble at low AOA. It does not work very well when the elevator is deflected.

Cheers,

Jay

 

From: main@Q-List.groups.io <main@Q-List.groups.io> On Behalf Of Bruce Crain
Sent: Thursday, March 19, 2020 8:32 PM
To: main@Q-List.groups.io
Subject: Re: [Q-List] Sparrow strainer stall

 

Say Jay I

think the tufts on the elevator were moving the same direction in normal cruise (from outboard to inboard) regardless of the sparrow strainer stalling or not stalling.  It could be exacerbating where the air flow goes due to the strainers moving up and being blanked by the elevator perhaps.  I except when I pull the stick and lower the strainer back to cruise pitch or lower it still takes stalling the canard to alleviate the sparrow strainer stall.  Maybe my outboard strainer is the difference between my Q and others but then I believe DFly's have outboard maybe.  Charlie can you back me up on that?  Or maybe no one else has actually pulled up and unloaded their Quickie to the extent that I have.

 

It has bothered me for a few years that the airflow on the elevator move inboard like it does.  To an aerodynamisist it means a big loss in speed doesn't it?  I am sure when the LS1 airfoil came out they had it working well.  Maybe it's just me.

Bruce Crain  

Please note: message attached

From: "Jay Scheevel" <jay@...>
To: <main@Q-List.groups.io>
Subject: Re: [Q-List] Sparrow strainer stall
Date: Thu, 19 Mar 2020 09:39:12 -0600

David J. Gall
 

Bruce,

The LS-1 airfoil has been a poor choice since day one, precisely because of the elevator shape that causes it to float trailing-edge up requiring sparrow strainers to counteract. And QAC knew it; it was never “working well.” In fact, it resulted in Burt coming over from RAF and trying to get them to go a different direction, resulting in the “breakup” of RAF and QAC. A MUCH better airfoil was already under development at RAF, now known as the Roncz 1145MS “new” canard airfoil for the Long-EZ. 

What you’re dealing with is uncharted territory since you’ve placed your sparrow strainers in a different location from “the plans,” but I would argue that even “the plans” had a less than thoroughly worked out specification for them. Nowhere has QAC ever addressed the stick-force and stick-position gradients or neutral point and CG range, or the corrections needed for airplanes that end up out of trim as a result of construction variances. These issues were thoroughly discussed in Rutan’s “Canard Pusher” newsletter but were never echoed in any QAC guidance.

All QAC ever addressed was ground handling, and they did it by various aerodynamic band-aids that contribute to bizarre and outright aberrant flight control positions in flight — and yet, there have been (to my knowledge) no resulting loss of control incidents. That’s NOT a testament to great aerodynamic design work, but to the cautious and judicious approach to flight testing and operations of the various builders, and this community of builders working together to corral the Mavericks before somebody hurts themselves. 

You’ve identified a regime in which your control forces change in an unexpected and undesirable manner. A stalled sparrow strainer is a potentially dangerous condition since the sparrow strainers are so intimately tied to the tactile and visceral kinesthetic sense we humans use to operate machinery “intuitively” when our higher brain functions are engaged in more pressing matters. In other words, in a clutch, the damn plane can unpredictably depart from expected behavior just when you really need it to be predictable. I hope you figure out how to fix this. But don’t expect that QAC ever really had it dialed in, either.

David J. Gall

On Mar 19, 2020, at 7:33 PM, Bruce Crain <jcrain2@...> wrote:


Say Jay I
think the tufts on the elevator were moving the same direction in normal cruise (from outboard to inboard) regardless of the sparrow strainer stalling or not stalling.  It could be exacerbating where the air flow goes due to the strainers moving up and being blanked by the elevator perhaps.  I except when I pull the stick and lower the strainer back to cruise pitch or lower it still takes stalling the canard to alleviate the sparrow strainer stall.  Maybe my outboard strainer is the difference between my Q and others but then I believe DFly's have outboard maybe.  Charlie can you back me up on that?  Or maybe no one else has actually pulled up and unloaded their Quickie to the extent that I have.
 
It has bothered me for a few years that the airflow on the elevator move inboard like it does.  To an aerodynamisist it means a big loss in speed doesn't it?  I am sure when the LS1 airfoil came out they had it working well.  Maybe it's just me.
Bruce Crain  

Please note: message attached

From: "Jay Scheevel" <jay@...>
To: <main@Q-List.groups.io>
Subject: Re: [Q-List] Sparrow strainer stall
Date: Thu, 19 Mar 2020 09:39:12 -0600

<mime-attachment>

Bruce Crain
 

Copy that David.
I wonder if the Roncz canard has the elevator top air moving in board at cruise or was it designed out?
I think Mark Shuck was working on a Roncz canard to the Quickie.  I don't know what he was planning to do with the calcs.  Would be interesting to see what he came up with and if it would work on the Quickie.  Need for speed!!
Bruce
 

---------- Original Message ----------
From: "David J. Gall" <David@...>
To: main@q-list.groups.io
Subject: Re: [Q-List] Sparrow strainer stall
Date: Fri, 20 Mar 2020 09:06:05 -0700

Bruce,
 
The LS-1 airfoil has been a poor choice since day one, precisely because of the elevator shape that causes it to float trailing-edge up requiring sparrow strainers to counteract. And QAC knew it; it was never “working well.” In fact, it resulted in Burt coming over from RAF and trying to get them to go a different direction, resulting in the “breakup” of RAF and QAC. A MUCH better airfoil was already under development at RAF, now known as the Roncz 1145MS “new” canard airfoil for the Long-EZ. 
 
What you’re dealing with is uncharted territory since you’ve placed your sparrow strainers in a different location from “the plans,” but I would argue that even “the plans” had a less than thoroughly worked out specification for them. Nowhere has QAC ever addressed the stick-force and stick-position gradients or neutral point and CG range, or the corrections needed for airplanes that end up out of trim as a result of construction variances. These issues were thoroughly discussed in Rutan’s “Canard Pusher” newsletter but were never echoed in any QAC guidance.
 
All QAC ever addressed was ground handling, and they did it by various aerodynamic band-aids that contribute to bizarre and outright aberrant flight control positions in flight — and yet, there have been (to my knowledge) no resulting loss of control incidents. That’s NOT a testament to great aerodynamic design work, but to the cautious and judicious approach to flight testing and operations of the various builders, and this community of builders working together to corral the Mavericks before somebody hurts themselves. 
 
You’ve identified a regime in which your control forces change in an unexpected and undesirable manner. A stalled sparrow strainer is a potentially dangerous condition since the sparrow strainers are so intimately tied to the tactile and visceral kinesthetic sense we humans use to operate machinery “intuitively” when our higher brain functions are engaged in more pressing matters. In other words, in a clutch, the damn plane can unpredictably depart from expected behavior just when you really need it to be predictable. I hope you figure out how to fix this. But don’t expect that QAC ever really had it dialed in, either.
 
David J. Gall

On Mar 19, 2020, at 7:33 PM, Bruce Crain <jcrain2@...> wrote:

Say Jay I
think the tufts on the elevator were moving the same direction in normal cruise (from outboard to inboard) regardless of the sparrow strainer stalling or not stalling.  It could be exacerbating where the air flow goes due to the strainers moving up and being blanked by the elevator perhaps.  I except when I pull the stick and lower the strainer back to cruise pitch or lower it still takes stalling the canard to alleviate the sparrow strainer stall.  Maybe my outboard strainer is the difference between my Q and others but then I believe DFly's have outboard maybe.  Charlie can you back me up on that?  Or maybe no one else has actually pulled up and unloaded their Quickie to the extent that I have.
 
It has bothered me for a few years that the airflow on the elevator move inboard like it does.  To an aerodynamisist it means a big loss in speed doesn't it?  I am sure when the LS1 airfoil came out they had it working well.  Maybe it's just me.
Bruce Crain  

Please note: message attached

From: "Jay Scheevel" <jay@...>
To: <main@Q-List.groups.io>
Subject: Re: [Q-List] Sparrow strainer stall
Date: Thu, 19 Mar 2020 09:39:12 -0600

<mime-attachment>

Bruce Crain
 

I don't  have a clue as it has been a looong time ago when I set up the strainers.  They were adjustable at first but the  extra bolt heads sticking out in the wind and also the rough texture of the unfinished stainers made the elevator ride up until I put an upside down flap on both of them to make them ride level in cruise.  When I finally glassed them into place they were more effective without the bolt heads so I sanded off enough of the upside down flap to get back cruise level.  Then I filled and sanded the strainers and again they were more effective so I had to sand off equal amounts of upside down flap on the strainers for cruise pitch.  Then lastly I finished primed and painted them and I ended up sanding all but a very small amount of those upside down flaps.  So I got back to almost plans built for level.  Then the stall showed  up when pushing over to lower the nose.
I probably have the most experience with the strainers in "Quickiedom" but then mine are a bit non standard.
 
I am almost finished with pulling the number 4 cylinder chasing an oil seep.  I looks like the through bolts can leak through the treads on many engines so I am putting an o ring into the 2 through bolts and remounting the cylinder and will let you all know how this plays out.
Stay tuned for the "Old and the restless quest for Quickie perfection"!
 
Bruce Crain 


---------- Original Message ----------
From: "One Sky Dog via Groups.Io" <Oneskydog@...>
To: main@q-list.groups.io
Subject: Re: [Q-List] Sparrow strainer stall
Date: Fri, 20 Mar 2020 03:55:32 -0700

Bruce,

 
I found your previous description of stalling the sparrow strainers.
 
What is the angle between the lower elevator surface and the bottom of the sparrow strainer airfoil?
 
Regards,


On Mar 19, 2020, at 7:39 PM, Bruce Crain <jcrain2@...> wrote:

Thanks David, 
For a moment I thought it gave me a bit faster airspeed but the I realized that the air was pretty turbulent and I was having a hard time trimming for straight and level.  I do know that someone said "if you trim the elevator up and compensate level cruise trim with the reflexor you get more airspeed.  I cannot confirm that was the case.  And yes the zig zag did work.  Just made the airplane ride nose high for cruise.
 
Bruce

---------- Original Message ----------
From: "David J. Gall" <David@...>
To: main@q-list.groups.io
Subject: Re: [Q-List] Sparrow strainer stall
Date: Thu, 19 Mar 2020 12:10:51 -0700

 

Bruce,
 
I don’t think the zig-zag tape “created drag” the way you describe it. To me, your description seems like the tape was doing exactly what it was supposed to be doing: keeping the airflow energized and attached. The fact that the now-attached airflow made the elevator “ride up” is exactly what one would expect from an improvement in the air flow over the top of the airfoil; instead of matching the new elevator position with reflexor, you could have accepted the “new normal” and trimmed for it. My bet is that you’ll see similar or identical results with VGs. Was the airplane slower as a result? If so, perhaps that was caused by the nose-high attitude you created when you trimmed the reflexor TE up instead of elevator TE down, and not by “added drag” from the zig-zag tape.
 
The problem with the sparrow strainer being stalled is that the little beastie is too small and/or too close to the elevator hinge line. This could be fixed in any of several ways, including making it bigger or re-contouring the elevator. 
 
I wouldn’t count the zig-zag tape as a failure — according to your description, it was eminently successful!
 
David J. Gall

On Mar 18, 2020, at 6:25 PM, Bruce Crain <jcrain2@...> wrote:

Jon, 
I tried the zig zag tape and did get the stall to go away right up the last test where I finally had all of the zig zag cleaned off.  With the zig zag the stall would not happen on the strainer but it created drag and dragged the strainer up and thus the elevator also.  The elevator would ride up a half inch or so and stay and I would reflex the ailerons up to compensate.
 
I am going to test actual vortex generators next.  Trying to make them small enough so that they don't  create drag and pull the elevator up.  So the zig zag did work but with less than great results for the trim I am used to seeing.
 
Before the next tests I am pulling a cylinder to check for a leak around a cylinder base stud or cylinder base o ring perhaps.
 
Bruce Crain


---------- Original Message ----------
From: "Jon Finley" <jd@...>
To: main@Q-List.groups.io
Subject: Re: [Q-List] Sparrow strainer stall
Date: Wed, 18 Mar 2020 11:41:07 -0700

Howdy Jay,

I recently heard a woman admit that there are "degrees of yes" - I was stunned. Of course, I was very familiar with this phenomena but had never heard the other gender actually admit to it. Now you are talking about "degrees of stalled" - please confirm your gender!! 

:-)

Seriously, I know you are correct. I also saw this in my GU canard tuft testing (moving up/forward on the airfoil). 

Bruce; I don't know what to say on your strainers. I struggled to know how to set them (and eventually gave up on them on my GU, since they weren't needed/per-plans (instead, springs take up the load, as I recall)).  I imagine you have already tried reducing their angle of attack - and noted some change in stick force?? 

Jon  

 

Jay Scheevel
 

Comparison model data of Roncz versus a few other airfoils of that vintage.

 

Cheers,

Jay

 

From: main@Q-List.groups.io <main@Q-List.groups.io> On Behalf Of Bruce Crain
Sent: Friday, March 20, 2020 4:30 PM
To: main@Q-List.groups.io
Subject: Re: [Q-List] Sparrow strainer stall

 

Copy that David.

I wonder if the Roncz canard has the elevator top air moving in board at cruise or was it designed out?

I think Mark Shuck was working on a Roncz canard to the Quickie.  I don't know what he was planning to do with the calcs.  Would be interesting to see what he came up with and if it would work on the Quickie.  Need for speed!!

Bruce

 


---------- Original Message ----------
From: "David J. Gall" <David@...>
To: main@q-list.groups.io
Subject: Re: [Q-List] Sparrow strainer stall
Date: Fri, 20 Mar 2020 09:06:05 -0700

Bruce,

 

The LS-1 airfoil has been a poor choice since day one, precisely because of the elevator shape that causes it to float trailing-edge up requiring sparrow strainers to counteract. And QAC knew it; it was never “working well.” In fact, it resulted in Burt coming over from RAF and trying to get them to go a different direction, resulting in the “breakup” of RAF and QAC. A MUCH better airfoil was already under development at RAF, now known as the Roncz 1145MS “new” canard airfoil for the Long-EZ. 

 

What you’re dealing with is uncharted territory since you’ve placed your sparrow strainers in a different location from “the plans,” but I would argue that even “the plans” had a less than thoroughly worked out specification for them. Nowhere has QAC ever addressed the stick-force and stick-position gradients or neutral point and CG range, or the corrections needed for airplanes that end up out of trim as a result of construction variances. These issues were thoroughly discussed in Rutan’s “Canard Pusher” newsletter but were never echoed in any QAC guidance.

 

All QAC ever addressed was ground handling, and they did it by various aerodynamic band-aids that contribute to bizarre and outright aberrant flight control positions in flight — and yet, there have been (to my knowledge) no resulting loss of control incidents. That’s NOT a testament to great aerodynamic design work, but to the cautious and judicious approach to flight testing and operations of the various builders, and this community of builders working together to corral the Mavericks before somebody hurts themselves. 

 

You’ve identified a regime in which your control forces change in an unexpected and undesirable manner. A stalled sparrow strainer is a potentially dangerous condition since the sparrow strainers are so intimately tied to the tactile and visceral kinesthetic sense we humans use to operate machinery “intuitively” when our higher brain functions are engaged in more pressing matters. In other words, in a clutch, the damn plane can unpredictably depart from expected behavior just when you really need it to be predictable. I hope you figure out how to fix this. But don’t expect that QAC ever really had it dialed in, either.

 

David J. Gall

 

On Mar 19, 2020, at 7:33 PM, Bruce Crain <jcrain2@...> wrote:

Say Jay I

think the tufts on the elevator were moving the same direction in normal cruise (from outboard to inboard) regardless of the sparrow strainer stalling or not stalling.  It could be exacerbating where the air flow goes due to the strainers moving up and being blanked by the elevator perhaps.  I except when I pull the stick and lower the strainer back to cruise pitch or lower it still takes stalling the canard to alleviate the sparrow strainer stall.  Maybe my outboard strainer is the difference between my Q and others but then I believe DFly's have outboard maybe.  Charlie can you back me up on that?  Or maybe no one else has actually pulled up and unloaded their Quickie to the extent that I have.

 

It has bothered me for a few years that the airflow on the elevator move inboard like it does.  To an aerodynamisist it means a big loss in speed doesn't it?  I am sure when the LS1 airfoil came out they had it working well.  Maybe it's just me.

Bruce Crain  

Please note: message attached

From: "Jay Scheevel" <jay@...>
To: <main@Q-List.groups.io>
Subject: Re: [Q-List] Sparrow strainer stall
Date: Thu, 19 Mar 2020 09:39:12 -0600

<mime-attachment>

Jay Scheevel
 

Comparison of shape of Roncz, and LS-1 airfoils. (from Q-talk 97)

 

From: main@Q-List.groups.io <main@Q-List.groups.io> On Behalf Of Bruce Crain
Sent: Friday, March 20, 2020 4:30 PM
To: main@Q-List.groups.io
Subject: Re: [Q-List] Sparrow strainer stall

 

Copy that David.

I wonder if the Roncz canard has the elevator top air moving in board at cruise or was it designed out?

I think Mark Shuck was working on a Roncz canard to the Quickie.  I don't know what he was planning to do with the calcs.  Would be interesting to see what he came up with and if it would work on the Quickie.  Need for speed!!

Bruce

 


---------- Original Message ----------
From: "David J. Gall" <David@...>
To: main@q-list.groups.io
Subject: Re: [Q-List] Sparrow strainer stall
Date: Fri, 20 Mar 2020 09:06:05 -0700

Bruce,

 

The LS-1 airfoil has been a poor choice since day one, precisely because of the elevator shape that causes it to float trailing-edge up requiring sparrow strainers to counteract. And QAC knew it; it was never “working well.” In fact, it resulted in Burt coming over from RAF and trying to get them to go a different direction, resulting in the “breakup” of RAF and QAC. A MUCH better airfoil was already under development at RAF, now known as the Roncz 1145MS “new” canard airfoil for the Long-EZ. 

 

What you’re dealing with is uncharted territory since you’ve placed your sparrow strainers in a different location from “the plans,” but I would argue that even “the plans” had a less than thoroughly worked out specification for them. Nowhere has QAC ever addressed the stick-force and stick-position gradients or neutral point and CG range, or the corrections needed for airplanes that end up out of trim as a result of construction variances. These issues were thoroughly discussed in Rutan’s “Canard Pusher” newsletter but were never echoed in any QAC guidance.

 

All QAC ever addressed was ground handling, and they did it by various aerodynamic band-aids that contribute to bizarre and outright aberrant flight control positions in flight — and yet, there have been (to my knowledge) no resulting loss of control incidents. That’s NOT a testament to great aerodynamic design work, but to the cautious and judicious approach to flight testing and operations of the various builders, and this community of builders working together to corral the Mavericks before somebody hurts themselves. 

 

You’ve identified a regime in which your control forces change in an unexpected and undesirable manner. A stalled sparrow strainer is a potentially dangerous condition since the sparrow strainers are so intimately tied to the tactile and visceral kinesthetic sense we humans use to operate machinery “intuitively” when our higher brain functions are engaged in more pressing matters. In other words, in a clutch, the damn plane can unpredictably depart from expected behavior just when you really need it to be predictable. I hope you figure out how to fix this. But don’t expect that QAC ever really had it dialed in, either.

 

David J. Gall

 

On Mar 19, 2020, at 7:33 PM, Bruce Crain <jcrain2@...> wrote:

Say Jay I

think the tufts on the elevator were moving the same direction in normal cruise (from outboard to inboard) regardless of the sparrow strainer stalling or not stalling.  It could be exacerbating where the air flow goes due to the strainers moving up and being blanked by the elevator perhaps.  I except when I pull the stick and lower the strainer back to cruise pitch or lower it still takes stalling the canard to alleviate the sparrow strainer stall.  Maybe my outboard strainer is the difference between my Q and others but then I believe DFly's have outboard maybe.  Charlie can you back me up on that?  Or maybe no one else has actually pulled up and unloaded their Quickie to the extent that I have.

 

It has bothered me for a few years that the airflow on the elevator move inboard like it does.  To an aerodynamisist it means a big loss in speed doesn't it?  I am sure when the LS1 airfoil came out they had it working well.  Maybe it's just me.

Bruce Crain  

Please note: message attached

From: "Jay Scheevel" <jay@...>
To: <main@Q-List.groups.io>
Subject: Re: [Q-List] Sparrow strainer stall
Date: Thu, 19 Mar 2020 09:39:12 -0600

<mime-attachment>

Bruce Crain
 

I like this picture.  I wasn't smart 'nough to understand the others you sent Jay.
 
I am noticing the aft end of the airfoils look different.  It looks like there is negative camber on the aft end of the LS1.  The Epler does away with that negative camber.  Would that negative camber make the aft end want to pull up on the elevator?  Plus would it make the airflow blurble up after the trailing edge of the elevator.  
Not sure about the top of the LS1 airflow going inboard with respect to the 2 airfoils!
Any speculation Jay?
Do we need to design a new airfoil for the canard on the Quickie to make it go faster or slow the stall speed?
"Not a Rock Scientist"  
Bruce Crain


Please note: message attached

From: "Jay Scheevel" <jay@...>
To: <main@Q-List.groups.io>
Subject: Re: [Q-List] Sparrow strainer stall
Date: Fri, 20 Mar 2020 17:54:41 -0600

Jay Scheevel
 

I think that the Roncz airfoil would probably have been the way to go, but unfortunately, as David said, Burt Rutan did not win that argument. I think, if that airfoil had been used, there would have been no need for the carbon fiber spar.  Maybe the next time Sam replaces his canard, he can use that airfoil 😊

 

Cheers,

Jay

 

From: main@Q-List.groups.io <main@Q-List.groups.io> On Behalf Of Bruce Crain
Sent: Saturday, March 21, 2020 3:56 PM
To: main@Q-List.groups.io
Subject: Re: [Q-List] Sparrow strainer stall

 

I like this picture.  I wasn't smart 'nough to understand the others you sent Jay.

 

I am noticing the aft end of the airfoils look different.  It looks like there is negative camber on the aft end of the LS1.  The Epler does away with that negative camber.  Would that negative camber make the aft end want to pull up on the elevator?  Plus would it make the airflow blurble up after the trailing edge of the elevator.  

Not sure about the top of the LS1 airflow going inboard with respect to the 2 airfoils!

Any speculation Jay?

Do we need to design a new airfoil for the canard on the Quickie to make it go faster or slow the stall speed?

"Not a Rock Scientist"  

Bruce Crain



Please note: message attached

From: "Jay Scheevel" <jay@...>
To: <main@Q-List.groups.io>
Subject: Re: [Q-List] Sparrow strainer stall
Date: Fri, 20 Mar 2020 17:54:41 -0600

Bruce Crain
 

Did they use the Roncz canard on the Amzoil Racer?  Didn't Burt design that bird?
Bruce


---------- Original Message ----------
From: "Jay Scheevel" <jay@...>
To: <main@Q-List.groups.io>
Subject: Re: [Q-List] Sparrow strainer stall
Date: Sun, 22 Mar 2020 20:05:32 -0600

I think that the Roncz airfoil would probably have been the way to go, but unfortunately, as David said, Burt Rutan did not win that argument. I think, if that airfoil had been used, there would have been no need for the carbon fiber spar.  Maybe the next time Sam replaces his canard, he can use that airfoil 😊

 

Cheers,

Jay

 

From: main@Q-List.groups.io <main@Q-List.groups.io> On Behalf Of Bruce Crain
Sent: Saturday, March 21, 2020 3:56 PM
To: main@Q-List.groups.io
Subject: Re: [Q-List] Sparrow strainer stall

 

I like this picture.  I wasn't smart 'nough to understand the others you sent Jay.

 

I am noticing the aft end of the airfoils look different.  It looks like there is negative camber on the aft end of the LS1.  The Epler does away with that negative camber.  Would that negative camber make the aft end want to pull up on the elevator?  Plus would it make the airflow blurble up after the trailing edge of the elevator.  

Not sure about the top of the LS1 airflow going inboard with respect to the 2 airfoils!

Any speculation Jay?

Do we need to design a new airfoil for the canard on the Quickie to make it go faster or slow the stall speed?

"Not a Rock Scientist"  

Bruce Crain



Please note: message attached

From: "Jay Scheevel" <jay@...>
To: <main@Q-List.groups.io>
Subject: Re: [Q-List] Sparrow strainer stall
Date: Fri, 20 Mar 2020 17:54:41 -0600

 

Jay Scheevel
 

I think it looked more like this.

 

 

From: main@Q-List.groups.io <main@Q-List.groups.io> On Behalf Of Bruce Crain
Sent: Sunday, March 22, 2020 8:21 PM
To: main@Q-List.groups.io
Subject: Re: [Q-List] Sparrow strainer stall

 

Did they use the Roncz canard on the Amzoil Racer?  Didn't Burt design that bird?

Bruce

---------- Original Message ----------
From: "Jay Scheevel" <jay@...>
To: <main@Q-List.groups.io>
Subject: Re: [Q-List] Sparrow strainer stall
Date: Sun, 22 Mar 2020 20:05:32 -0600

I think that the Roncz airfoil would probably have been the way to go, but unfortunately, as David said, Burt Rutan did not win that argument. I think, if that airfoil had been used, there would have been no need for the carbon fiber spar.  Maybe the next time Sam replaces his canard, he can use that airfoil 😊

 

Cheers,

Jay

 

From: main@Q-List.groups.io <main@Q-List.groups.io> On Behalf Of Bruce Crain
Sent: Saturday, March 21, 2020 3:56 PM
To: main@Q-List.groups.io
Subject: Re: [Q-List] Sparrow strainer stall

 

I like this picture.  I wasn't smart 'nough to understand the others you sent Jay.

 

I am noticing the aft end of the airfoils look different.  It looks like there is negative camber on the aft end of the LS1.  The Epler does away with that negative camber.  Would that negative camber make the aft end want to pull up on the elevator?  Plus would it make the airflow blurble up after the trailing edge of the elevator.  

Not sure about the top of the LS1 airflow going inboard with respect to the 2 airfoils!

Any speculation Jay?

Do we need to design a new airfoil for the canard on the Quickie to make it go faster or slow the stall speed?

"Not a Rock Scientist"  

Bruce Crain



Please note: message attached

From: "Jay Scheevel" <jay@...>
To: <main@Q-List.groups.io>
Subject: Re: [Q-List] Sparrow strainer stall
Date: Fri, 20 Mar 2020 17:54:41 -0600

 

Bruce Crain
 

Looks almost symmetrical!  Would perhaps need a bit of up incidence for cruise.  But then you're not looking for just cruise when racing!
Bruce

Please note: message attached

From: "Jay Scheevel" <jay@...>
To: <main@Q-List.groups.io>
Subject: Re: [Q-List] Sparrow strainer stall
Date: Sun, 22 Mar 2020 21:07:55 -0600

Jay Scheevel
 

Since it was built as a pylon racer, the mission was quite different than fast cruise. Not sure, but I think Roncz designed the Amsoil airfoils also. Take a look at the area behind the 50% chord, you will see the camber there, but you are right, it is close to symmetrical.

 

Cheers,

Jay

 

From: main@Q-List.groups.io <main@Q-List.groups.io> On Behalf Of Bruce Crain
Sent: Monday, March 23, 2020 8:14 AM
To: main@Q-List.groups.io
Subject: Re: [Q-List] Sparrow strainer stall

 

Looks almost symmetrical!  Would perhaps need a bit of up incidence for cruise.  But then you're not looking for just cruise when racing!

Bruce

Please note: message attached

From: "Jay Scheevel" <jay@...>
To: <main@Q-List.groups.io>
Subject: Re: [Q-List] Sparrow strainer stall
Date: Sun, 22 Mar 2020 21:07:55 -0600

Rik
 

To date, has there been a Q with the Roncz airfoil built and flown?

David J. Gall
 

Jay,

 

I think you’ve got the wrong airfoil there. The topic of discussion is canard airfoil, you’re showing the Amsoil Racer *wing* airfoil.

 

That said, what airfoil software are you using?

 

 

David J. Gall

 

From: main@Q-List.groups.io <main@Q-List.groups.io> On Behalf Of Jay Scheevel
Sent: Sunday, March 22, 2020 8:08 PM
To: main@Q-List.groups.io
Subject: Re: [Q-List] Sparrow strainer stall

 

I think it looked more like this.

 

 

From: main@Q-List.groups.io <main@Q-List.groups.io> On Behalf Of Bruce Crain
Sent: Sunday, March 22, 2020 8:21 PM
To: main@Q-List.groups.io
Subject: Re: [Q-List] Sparrow strainer stall

 

Did they use the Roncz canard on the Amzoil Racer?  Didn't Burt design that bird?

Bruce

---------- Original Message ----------
From: "Jay Scheevel" <jay@...>
To: <main@Q-List.groups.io>
Subject: Re: [Q-List] Sparrow strainer stall
Date: Sun, 22 Mar 2020 20:05:32 -0600

I think that the Roncz airfoil would probably have been the way to go, but unfortunately, as David said, Burt Rutan did not win that argument. I think, if that airfoil had been used, there would have been no need for the carbon fiber spar.  Maybe the next time Sam replaces his canard, he can use that airfoil 😊

 

Cheers,

Jay

 

From: main@Q-List.groups.io <main@Q-List.groups.io> On Behalf Of Bruce Crain
Sent: Saturday, March 21, 2020 3:56 PM
To: main@Q-List.groups.io
Subject: Re: [Q-List] Sparrow strainer stall

 

I like this picture.  I wasn't smart 'nough to understand the others you sent Jay.

 

I am noticing the aft end of the airfoils look different.  It looks like there is negative camber on the aft end of the LS1.  The Epler does away with that negative camber.  Would that negative camber make the aft end want to pull up on the elevator?  Plus would it make the airflow blurble up after the trailing edge of the elevator.  

Not sure about the top of the LS1 airflow going inboard with respect to the 2 airfoils!

Any speculation Jay?

Do we need to design a new airfoil for the canard on the Quickie to make it go faster or slow the stall speed?

"Not a Rock Scientist"  

Bruce Crain



Please note: message attached

From: "Jay Scheevel" <jay@...>
To: <main@Q-List.groups.io>
Subject: Re: [Q-List] Sparrow strainer stall
Date: Fri, 20 Mar 2020 17:54:41 -0600

 

Jay Scheevel
 

Hi David,

 

This is what I got off the University of Illinois airfoil database. There are two airfoils there listed under Rutan Amsoil racer. They look to be very similar. I wonder if they used nearly the same airfoil on both wings, but with differing incidences. Here is the only photo I could find of it but it is difficult to tell from this angle (I thin this is the second one built, first was destroyed in the crash).

 

From: main@Q-List.groups.io <main@Q-List.groups.io> On Behalf Of David J. Gall
Sent: Monday, March 23, 2020 5:17 PM
To: main@Q-List.groups.io
Subject: Re: [Q-List] Sparrow strainer stall

 

Jay,

 

I think you’ve got the wrong airfoil there. The topic of discussion is canard airfoil, you’re showing the Amsoil Racer *wing* airfoil.

 

That said, what airfoil software are you using?

 

 

David J. Gall

 

From: main@Q-List.groups.io <main@Q-List.groups.io> On Behalf Of Jay Scheevel
Sent: Sunday, March 22, 2020 8:08 PM
To: main@Q-List.groups.io
Subject: Re: [Q-List] Sparrow strainer stall

 

I think it looked more like this.

 

 

From: main@Q-List.groups.io <main@Q-List.groups.io> On Behalf Of Bruce Crain
Sent: Sunday, March 22, 2020 8:21 PM
To: main@Q-List.groups.io
Subject: Re: [Q-List] Sparrow strainer stall

 

Did they use the Roncz canard on the Amzoil Racer?  Didn't Burt design that bird?

Bruce

---------- Original Message ----------
From: "Jay Scheevel" <jay@...>
To: <main@Q-List.groups.io>
Subject: Re: [Q-List] Sparrow strainer stall
Date: Sun, 22 Mar 2020 20:05:32 -0600

I think that the Roncz airfoil would probably have been the way to go, but unfortunately, as David said, Burt Rutan did not win that argument. I think, if that airfoil had been used, there would have been no need for the carbon fiber spar.  Maybe the next time Sam replaces his canard, he can use that airfoil 😊

 

Cheers,

Jay

 

From: main@Q-List.groups.io <main@Q-List.groups.io> On Behalf Of Bruce Crain
Sent: Saturday, March 21, 2020 3:56 PM
To: main@Q-List.groups.io
Subject: Re: [Q-List] Sparrow strainer stall

 

I like this picture.  I wasn't smart 'nough to understand the others you sent Jay.

 

I am noticing the aft end of the airfoils look different.  It looks like there is negative camber on the aft end of the LS1.  The Epler does away with that negative camber.  Would that negative camber make the aft end want to pull up on the elevator?  Plus would it make the airflow blurble up after the trailing edge of the elevator.  

Not sure about the top of the LS1 airflow going inboard with respect to the 2 airfoils!

Any speculation Jay?

Do we need to design a new airfoil for the canard on the Quickie to make it go faster or slow the stall speed?

"Not a Rock Scientist"  

Bruce Crain



Please note: message attached

From: "Jay Scheevel" <jay@...>
To: <main@Q-List.groups.io>
Subject: Re: [Q-List] Sparrow strainer stall
Date: Fri, 20 Mar 2020 17:54:41 -0600

 

Jay Scheevel
 

 

Here’s another one:

From: main@Q-List.groups.io <main@Q-List.groups.io> On Behalf Of Jay Scheevel
Sent: Monday, March 23, 2020 6:09 PM
To: main@Q-List.groups.io
Subject: Re: [Q-List] Sparrow strainer stall

 

Hi David,

 

This is what I got off the University of Illinois airfoil database. There are two airfoils there listed under Rutan Amsoil racer. They look to be very similar. I wonder if they used nearly the same airfoil on both wings, but with differing incidences. Here is the only photo I could find of it but it is difficult to tell from this angle (I thin this is the second one built, first was destroyed in the crash).

 

From: main@Q-List.groups.io <main@Q-List.groups.io> On Behalf Of David J. Gall
Sent: Monday, March 23, 2020 5:17 PM
To: main@Q-List.groups.io
Subject: Re: [Q-List] Sparrow strainer stall

 

Jay,

 

I think you’ve got the wrong airfoil there. The topic of discussion is canard airfoil, you’re showing the Amsoil Racer *wing* airfoil.

 

That said, what airfoil software are you using?

 

 

David J. Gall

 

From: main@Q-List.groups.io <main@Q-List.groups.io> On Behalf Of Jay Scheevel
Sent: Sunday, March 22, 2020 8:08 PM
To: main@Q-List.groups.io
Subject: Re: [Q-List] Sparrow strainer stall

 

I think it looked more like this.

 

 

From: main@Q-List.groups.io <main@Q-List.groups.io> On Behalf Of Bruce Crain
Sent: Sunday, March 22, 2020 8:21 PM
To: main@Q-List.groups.io
Subject: Re: [Q-List] Sparrow strainer stall

 

Did they use the Roncz canard on the Amzoil Racer?  Didn't Burt design that bird?

Bruce

---------- Original Message ----------
From: "Jay Scheevel" <jay@...>
To: <main@Q-List.groups.io>
Subject: Re: [Q-List] Sparrow strainer stall
Date: Sun, 22 Mar 2020 20:05:32 -0600

I think that the Roncz airfoil would probably have been the way to go, but unfortunately, as David said, Burt Rutan did not win that argument. I think, if that airfoil had been used, there would have been no need for the carbon fiber spar.  Maybe the next time Sam replaces his canard, he can use that airfoil 😊

 

Cheers,

Jay

 

From: main@Q-List.groups.io <main@Q-List.groups.io> On Behalf Of Bruce Crain
Sent: Saturday, March 21, 2020 3:56 PM
To: main@Q-List.groups.io
Subject: Re: [Q-List] Sparrow strainer stall

 

I like this picture.  I wasn't smart 'nough to understand the others you sent Jay.

 

I am noticing the aft end of the airfoils look different.  It looks like there is negative camber on the aft end of the LS1.  The Epler does away with that negative camber.  Would that negative camber make the aft end want to pull up on the elevator?  Plus would it make the airflow blurble up after the trailing edge of the elevator.  

Not sure about the top of the LS1 airflow going inboard with respect to the 2 airfoils!

Any speculation Jay?

Do we need to design a new airfoil for the canard on the Quickie to make it go faster or slow the stall speed?

"Not a Rock Scientist"  

Bruce Crain



Please note: message attached

From: "Jay Scheevel" <jay@...>
To: <main@Q-List.groups.io>
Subject: Re: [Q-List] Sparrow strainer stall
Date: Fri, 20 Mar 2020 17:54:41 -0600

 

David J. Gall
 

Jay,

 

The UIUC airfoil database has two files: AMSOIL1.DAT is the canard airfoil, AMSOIL2.DAT is the wing airfoil. They’re similar, but the canard airfoil has more camber. I’ve done zero analysis on them….

 

 

David J. Gall

 

 

From: main@Q-List.groups.io <main@Q-List.groups.io> On Behalf Of Jay Scheevel
Sent: Monday, March 23, 2020 5:13 PM
To: main@Q-List.groups.io
Subject: Re: [Q-List] Sparrow strainer stall

 

 

Here’s another one:

From: main@Q-List.groups.io <main@Q-List.groups.io> On Behalf Of Jay Scheevel
Sent: Monday, March 23, 2020 6:09 PM
To: main@Q-List.groups.io
Subject: Re: [Q-List] Sparrow strainer stall

 

Hi David,

 

This is what I got off the University of Illinois airfoil database. There are two airfoils there listed under Rutan Amsoil racer. They look to be very similar. I wonder if they used nearly the same airfoil on both wings, but with differing incidences. Here is the only photo I could find of it but it is difficult to tell from this angle (I thin this is the second one built, first was destroyed in the crash).

 

From: main@Q-List.groups.io <main@Q-List.groups.io> On Behalf Of David J. Gall
Sent: Monday, March 23, 2020 5:17 PM
To: main@Q-List.groups.io
Subject: Re: [Q-List] Sparrow strainer stall

 

Jay,

 

I think you’ve got the wrong airfoil there. The topic of discussion is canard airfoil, you’re showing the Amsoil Racer *wing* airfoil.

 

That said, what airfoil software are you using?

 

 

David J. Gall

 

From: main@Q-List.groups.io <main@Q-List.groups.io> On Behalf Of Jay Scheevel
Sent: Sunday, March 22, 2020 8:08 PM
To: main@Q-List.groups.io
Subject: Re: [Q-List] Sparrow strainer stall

 

I think it looked more like this.

 

 

From: main@Q-List.groups.io <main@Q-List.groups.io> On Behalf Of Bruce Crain
Sent: Sunday, March 22, 2020 8:21 PM
To: main@Q-List.groups.io
Subject: Re: [Q-List] Sparrow strainer stall

 

Did they use the Roncz canard on the Amzoil Racer?  Didn't Burt design that bird?

Bruce

---------- Original Message ----------
From: "Jay Scheevel" <jay@...>
To: <main@Q-List.groups.io>
Subject: Re: [Q-List] Sparrow strainer stall
Date: Sun, 22 Mar 2020 20:05:32 -0600

I think that the Roncz airfoil would probably have been the way to go, but unfortunately, as David said, Burt Rutan did not win that argument. I think, if that airfoil had been used, there would have been no need for the carbon fiber spar.  Maybe the next time Sam replaces his canard, he can use that airfoil 😊

 

Cheers,

Jay

 

From: main@Q-List.groups.io <main@Q-List.groups.io> On Behalf Of Bruce Crain
Sent: Saturday, March 21, 2020 3:56 PM
To: main@Q-List.groups.io
Subject: Re: [Q-List] Sparrow strainer stall

 

I like this picture.  I wasn't smart 'nough to understand the others you sent Jay.

 

I am noticing the aft end of the airfoils look different.  It looks like there is negative camber on the aft end of the LS1.  The Epler does away with that negative camber.  Would that negative camber make the aft end want to pull up on the elevator?  Plus would it make the airflow blurble up after the trailing edge of the elevator.  

Not sure about the top of the LS1 airflow going inboard with respect to the 2 airfoils!

Any speculation Jay?

Do we need to design a new airfoil for the canard on the Quickie to make it go faster or slow the stall speed?

"Not a Rock Scientist"  

Bruce Crain



Please note: message attached

From: "Jay Scheevel" <jay@...>
To: <main@Q-List.groups.io>
Subject: Re: [Q-List] Sparrow strainer stall
Date: Fri, 20 Mar 2020 17:54:41 -0600

 

Bruce Crain
 

I see no Sparrow Strainer!  We've been "punked"!  Shoulda, Coulda Woulda!
B

Please note: message attached

From: "Jay Scheevel" <jay@...>
To: <main@Q-List.groups.io>
Subject: Re: [Q-List] Sparrow strainer stall
Date: Mon, 23 Mar 2020 18:13:28 -0600

David J. Gall
 

Bruce,

There would be no sparrow strainers on a Roncz canard, and the Roncz airfoil is thick enough (20.5%) vs. the GU thickness (21%) that the standard GU canard construction method could be used with, perhaps, a slight tweak to the spar layup schedule (no carbon spar needed).

Punked, indeed!

David J. Gall

On Mar 23, 2020, at 8:06 PM, Bruce Crain <jcrain2@...> wrote:


I see no Sparrow Strainer!  We've been "punked"!  Shoulda, Coulda Woulda!
B

Please note: message attached

From: "Jay Scheevel" <jay@...>
To: <main@Q-List.groups.io>
Subject: Re: [Q-List] Sparrow strainer stall
Date: Mon, 23 Mar 2020 18:13:28 -0600

<mime-attachment>