Topics

Sparrow strainer stall

Jay Scheevel
 

Thanks for the standard practice guidance, David. Always appreciated.

 

Cheers,

Jay

 

From: main@Q-List.groups.io <main@Q-List.groups.io> On Behalf Of David J. Gall
Sent: Tuesday, March 24, 2020 4:09 PM
To: main@q-list.groups.io
Subject: Re: [Q-List] Sparrow strainer stall

 

Jay,

 

Javafoil, of course! Try to design so that the elevator’s natural float angle is correct for the best rate-of-climb airspeed. This is the desired condition in case of trim failure and/or total loss of elevator control linkage. It’s slow, but allows completion of almost any long overwater flight before fuel exhaustion, and slow enough to do a reasonable job of landing using only power to “flare.” (Or reflex if you have one. 😉)

 

Springs as a primary pitch trim system are always a bad idea. If you use springs, try to use them as “down” springs only, meaning that the spring pushes the elevator in the same direction that forward control stick pressure would push it. The spring should work against the elevator’s natural aerodynamic desire to bring the nose up, except at very slow air speeds (slower than Vy) it’s OK to have a spring helping to bias the nose up, but limit that spring so that you can’t “trim into a stall” at least not at normal or forward CG. 

 

Matthew Curcio could probably chime in here with some industry-standard advice....

 

 

David J. Gall



On Mar 24, 2020, at 2:54 PM, Jay Scheevel <jay@...> wrote:



Thanks David,

 

I will keep at it. Maybe I will add a little reflex to the trailing edge. It is possible to design the elevator so pressure loads are essentially zero when it is not deflected. I can load the GU to see what it does, because it did not require sparrow strainers. It may have required some spring assisted trim, I don’t recall.

 

I am using Javafoil. It is Martin Hepperle’s freeware.  I like it because it is simple and I am simple.

 

Cheers,

Jay

 

From: main@Q-List.groups.io <main@Q-List.groups.io> On Behalf Of David J. Gall
Sent: Tuesday, March 24, 2020 3:36 PM
To: main@q-list.groups.io
Subject: Re: [Q-List] Sparrow strainer stall

 

Jay,

 

Nice work. Your modified LS1 elevator would go a long way toward reducing the workload required of the sparrow strainers, but you’d still need something like sparrow strainers to push the TE down for normal ops. The Roncz airfoil’s elevator is intentionally designed with a slight “reflex” on the trailing edge just so that it won’t need sparrow strainers or trim tabs. I suppose that with a little more work you could achieve the same with your modified LS1 elevator. 

 

Keep at it!

 

(BTW, what software is that?)

 

 

David J. Gall




On Mar 24, 2020, at 8:38 AM, Jay Scheevel <jay@...> wrote:



Hi Bruce,

 

A few years ago, I tried modeling the existing LS1 and only changing the shape of the elevator to try to eliminate the strong asymmetric pressure on the trailing edge (which is the reason you need the sparrow strainer). The reasoning was, that maybe someday, I would build a new set of elevators with the revised shape and leave the sparrow strainer off because it would not be needed. Here is a comparison of the pressure distribution on the the original LS1 for 0,3,and 6 degrees AOA (first graph) and for the same airfoil with the revised elevator (second graph), which would fit in the same slot. Note the difference in pressure on the top/bottom near the trailing edge. The modified version provides slightly lower lift than the original.

<image002.png>

<image001.png>

<image005.png>

<image006.png>

 

 

 

From: main@Q-List.groups.io <main@Q-List.groups.io> On Behalf Of Bruce Crain
Sent: Monday, March 23, 2020 9:04 PM
To: main@Q-List.groups.io
Subject: Re: [Q-List] Sparrow strainer stall

 

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
 

Jay,

Javafoil, of course! Try to design so that the elevator’s natural float angle is correct for the best rate-of-climb airspeed. This is the desired condition in case of trim failure and/or total loss of elevator control linkage. It’s slow, but allows completion of almost any long overwater flight before fuel exhaustion, and slow enough to do a reasonable job of landing using only power to “flare.” (Or reflex if you have one. 😉)

Springs as a primary pitch trim system are always a bad idea. If you use springs, try to use them as “down” springs only, meaning that the spring pushes the elevator in the same direction that forward control stick pressure would push it. The spring should work against the elevator’s natural aerodynamic desire to bring the nose up, except at very slow air speeds (slower than Vy) it’s OK to have a spring helping to bias the nose up, but limit that spring so that you can’t “trim into a stall” at least not at normal or forward CG. 

Matthew Curcio could probably chime in here with some industry-standard advice....


David J. Gall

On Mar 24, 2020, at 2:54 PM, Jay Scheevel <jay@...> wrote:



Thanks David,

 

I will keep at it. Maybe I will add a little reflex to the trailing edge. It is possible to design the elevator so pressure loads are essentially zero when it is not deflected. I can load the GU to see what it does, because it did not require sparrow strainers. It may have required some spring assisted trim, I don’t recall.

 

I am using Javafoil. It is Martin Hepperle’s freeware.  I like it because it is simple and I am simple.

 

Cheers,

Jay

 

From: main@Q-List.groups.io <main@Q-List.groups.io> On Behalf Of David J. Gall
Sent: Tuesday, March 24, 2020 3:36 PM
To: main@q-list.groups.io
Subject: Re: [Q-List] Sparrow strainer stall

 

Jay,

 

Nice work. Your modified LS1 elevator would go a long way toward reducing the workload required of the sparrow strainers, but you’d still need something like sparrow strainers to push the TE down for normal ops. The Roncz airfoil’s elevator is intentionally designed with a slight “reflex” on the trailing edge just so that it won’t need sparrow strainers or trim tabs. I suppose that with a little more work you could achieve the same with your modified LS1 elevator. 

 

Keep at it!

 

(BTW, what software is that?)

 

 

David J. Gall



On Mar 24, 2020, at 8:38 AM, Jay Scheevel <jay@...> wrote:



Hi Bruce,

 

A few years ago, I tried modeling the existing LS1 and only changing the shape of the elevator to try to eliminate the strong asymmetric pressure on the trailing edge (which is the reason you need the sparrow strainer). The reasoning was, that maybe someday, I would build a new set of elevators with the revised shape and leave the sparrow strainer off because it would not be needed. Here is a comparison of the pressure distribution on the the original LS1 for 0,3,and 6 degrees AOA (first graph) and for the same airfoil with the revised elevator (second graph), which would fit in the same slot. Note the difference in pressure on the top/bottom near the trailing edge. The modified version provides slightly lower lift than the original.

<image002.png>

<image001.png>

<image005.png>

<image006.png>

 

 

 

From: main@Q-List.groups.io <main@Q-List.groups.io> On Behalf Of Bruce Crain
Sent: Monday, March 23, 2020 9:04 PM
To: main@Q-List.groups.io
Subject: Re: [Q-List] Sparrow strainer stall

 

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

Jay Scheevel
 

Thanks David,

 

I will keep at it. Maybe I will add a little reflex to the trailing edge. It is possible to design the elevator so pressure loads are essentially zero when it is not deflected. I can load the GU to see what it does, because it did not require sparrow strainers. It may have required some spring assisted trim, I don’t recall.

 

I am using Javafoil. It is Martin Hepperle’s freeware.  I like it because it is simple and I am simple.

 

Cheers,

Jay

 

From: main@Q-List.groups.io <main@Q-List.groups.io> On Behalf Of David J. Gall
Sent: Tuesday, March 24, 2020 3:36 PM
To: main@q-list.groups.io
Subject: Re: [Q-List] Sparrow strainer stall

 

Jay,

 

Nice work. Your modified LS1 elevator would go a long way toward reducing the workload required of the sparrow strainers, but you’d still need something like sparrow strainers to push the TE down for normal ops. The Roncz airfoil’s elevator is intentionally designed with a slight “reflex” on the trailing edge just so that it won’t need sparrow strainers or trim tabs. I suppose that with a little more work you could achieve the same with your modified LS1 elevator. 

 

Keep at it!

 

(BTW, what software is that?)

 

 

David J. Gall



On Mar 24, 2020, at 8:38 AM, Jay Scheevel <jay@...> wrote:



Hi Bruce,

 

A few years ago, I tried modeling the existing LS1 and only changing the shape of the elevator to try to eliminate the strong asymmetric pressure on the trailing edge (which is the reason you need the sparrow strainer). The reasoning was, that maybe someday, I would build a new set of elevators with the revised shape and leave the sparrow strainer off because it would not be needed. Here is a comparison of the pressure distribution on the the original LS1 for 0,3,and 6 degrees AOA (first graph) and for the same airfoil with the revised elevator (second graph), which would fit in the same slot. Note the difference in pressure on the top/bottom near the trailing edge. The modified version provides slightly lower lift than the original.

<image002.png>

<image001.png>

<image005.png>

<image006.png>

 

 

 

From: main@Q-List.groups.io <main@Q-List.groups.io> On Behalf Of Bruce Crain
Sent: Monday, March 23, 2020 9:04 PM
To: main@Q-List.groups.io
Subject: Re: [Q-List] Sparrow strainer stall

 

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,

Jay’s elevator needs a bit more “reflex” on its trailing edge before it could completely go without a sparrow strainer or trim tab. But he’s on the right track. 

Washout is not a hindrance to airfoil substitution, but willpower is. Would a Jay Scheevel-modified LS1 be “better” than a Roncz airfoil? Define “better:” if you already have an LS1 canard, changing out the elevator is “better” than building a new canard. If “better” means more suitable for new construction, then having QAC carbon spars on hand might weight the contest. If “better” means “higher cruise speed” or “lower landing speed,” well... you get the idea. 

To me, the Roncz airfoil is appealing for new construction because it’s almost the same thickness as the GU — I think I could fudge it a bit and use the same structure as the GU. BUT, then I’d be limited to the lower gross weight of the Q2 instead of the Q200 unless I beefed up the structure. Then I’d be in structural design and analysis mode, so 🤷‍♂️! However, for the Q1 it would be a drop-in replacement............. 🤔

David J. Gall

On Mar 24, 2020, at 11:23 AM, Bruce Crain <jcrain2@...> wrote:


So Jay,
Are you saying that the LS1 with a different elevator would not need a sparrow strainer?  Would it be better than a Roncz canard?
 
I also remember the main wing has wash out.  But I cannot remember if the canard does.  i would have to get out my templates to look unless someone remembers.  If there is wash out that would make designing a Roncz canard off of the templates pretty difficult.  Is it even possible?
Bruce

Please note: message attached

From: "Jay Scheevel" <jay@...>
To: <main@Q-List.groups.io>
Subject: Re: [Q-List] Sparrow strainer stall
Date: Tue, 24 Mar 2020 09:38:13 -0600

<mime-attachment>

David J. Gall
 

Jay,

Nice work. Your modified LS1 elevator would go a long way toward reducing the workload required of the sparrow strainers, but you’d still need something like sparrow strainers to push the TE down for normal ops. The Roncz airfoil’s elevator is intentionally designed with a slight “reflex” on the trailing edge just so that it won’t need sparrow strainers or trim tabs. I suppose that with a little more work you could achieve the same with your modified LS1 elevator. 

Keep at it!

(BTW, what software is that?)


David J. Gall

On Mar 24, 2020, at 8:38 AM, Jay Scheevel <jay@...> wrote:



Hi Bruce,

 

A few years ago, I tried modeling the existing LS1 and only changing the shape of the elevator to try to eliminate the strong asymmetric pressure on the trailing edge (which is the reason you need the sparrow strainer). The reasoning was, that maybe someday, I would build a new set of elevators with the revised shape and leave the sparrow strainer off because it would not be needed. Here is a comparison of the pressure distribution on the the original LS1 for 0,3,and 6 degrees AOA (first graph) and for the same airfoil with the revised elevator (second graph), which would fit in the same slot. Note the difference in pressure on the top/bottom near the trailing edge. The modified version provides slightly lower lift than the original.

<image002.png>

<image001.png>

<image005.png>

<image006.png>

 

 

 

From: main@Q-List.groups.io <main@Q-List.groups.io> On Behalf Of Bruce Crain
Sent: Monday, March 23, 2020 9:04 PM
To: main@Q-List.groups.io
Subject: Re: [Q-List] Sparrow strainer stall

 

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

Bruce Crain
 

Soooo maybe when we meet at Oshkosh for our "40 Year Reunion" this summer we can corner Burt and see if he could advise.  He is available at times.  Huuuumm.
Bruce

Please note: message attached

From: "Jay Scheevel" <jay@...>
To: <main@Q-List.groups.io>
Subject: Re: [Q-List] Sparrow strainer stall
Date: Tue, 24 Mar 2020 13:47:47 -0600

Jay Scheevel
 

With a different elevator, there would be no need for the sparrow strainer, but it would not produce as much lift, so may need more incidence or other adjustments. Not sure about the Roncz canard, I have never modeled it. The LS1 canard also has washout, not as much as the main wing, but I don’t remember how much. Here is a picture of the three: BL16, BL50, and BL100 templates, level lines horizontal and trailing edges matched up.

 

Cheers,

Jay

 

From: main@Q-List.groups.io <main@Q-List.groups.io> On Behalf Of Bruce Crain
Sent: Tuesday, March 24, 2020 12:22 PM
To: main@Q-List.groups.io
Subject: Re: [Q-List] Sparrow strainer stall

 

So Jay,

Are you saying that the LS1 with a different elevator would not need a sparrow strainer?  Would it be better than a Roncz canard?

 

I also remember the main wing has wash out.  But I cannot remember if the canard does.  i would have to get out my templates to look unless someone remembers.  If there is wash out that would make designing a Roncz canard off of the templates pretty difficult.  Is it even possible?

Bruce

Please note: message attached

From: "Jay Scheevel" <jay@...>
To: <main@Q-List.groups.io>
Subject: Re: [Q-List] Sparrow strainer stall
Date: Tue, 24 Mar 2020 09:38:13 -0600

Bruce Crain
 

So Jay,
Are you saying that the LS1 with a different elevator would not need a sparrow strainer?  Would it be better than a Roncz canard?
 
I also remember the main wing has wash out.  But I cannot remember if the canard does.  i would have to get out my templates to look unless someone remembers.  If there is wash out that would make designing a Roncz canard off of the templates pretty difficult.  Is it even possible?
Bruce

Please note: message attached

From: "Jay Scheevel" <jay@...>
To: <main@Q-List.groups.io>
Subject: Re: [Q-List] Sparrow strainer stall
Date: Tue, 24 Mar 2020 09:38:13 -0600

Bruce Crain
 

Sweet!  I built the Waddelow Canard for my TriQ 200.  With you that assortment of spar caps and 2 shear webs etc make for a Roncz mid?
Bruce Crain


On Mar 24, 2020, at 9:40 AM, David J. Gall <David@...> wrote:


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>

Jay Scheevel
 

Hi Bruce,

 

A few years ago, I tried modeling the existing LS1 and only changing the shape of the elevator to try to eliminate the strong asymmetric pressure on the trailing edge (which is the reason you need the sparrow strainer). The reasoning was, that maybe someday, I would build a new set of elevators with the revised shape and leave the sparrow strainer off because it would not be needed. Here is a comparison of the pressure distribution on the the original LS1 for 0,3,and 6 degrees AOA (first graph) and for the same airfoil with the revised elevator (second graph), which would fit in the same slot. Note the difference in pressure on the top/bottom near the trailing edge. The modified version provides slightly lower lift than the original.

 

 

 

From: main@Q-List.groups.io <main@Q-List.groups.io> On Behalf Of Bruce Crain
Sent: Monday, March 23, 2020 9:04 PM
To: main@Q-List.groups.io
Subject: Re: [Q-List] Sparrow strainer stall

 

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>

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
 

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

 

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

 

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

 

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

 

Rik
 

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

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

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
 

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