Re: Sparrow strainer stall
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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
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
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
I think it looked more like this.
From: main@Q-List.groups.io <main@Q-List.groups.io> On Behalf Of Bruce Crain
Did they use the Roncz canard on the Amzoil Racer? Didn't Burt design that bird? Bruce 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
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
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