Re: Sparrow strainer stall

Bruce Crain
 

On the bottom as the stall was happening on the underneath side of the strainer.  The tufts on the aft of the strainers were disappearing underneath the strainers.
Bruce 


---------- Original Message ----------
From: "Jay Scheevel" <jay@...>
To: main@Q-List.groups.io
Subject: Re: [Q-List] Sparrow strainer stall
Date: Wed, 18 Mar 2020 19:44:54 -0600

Bruce,
which side of the strainer did you put the zigzag tape on? Top or bottom?
Jay
 
 
Sent from my Verizon Wireless 4G LTE DROID



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  

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