Frans...see indented comments below...Fred
On Aug 6, 2012, at 3:42 AM, Frans Veldman wrote:
> How much air is going to this gap with the flaps extended? Is it
> possible to make the underside of the wing flush with the flaps when
> the
> flaps are retracted?
..."possible"...but not necessarily desireable...this type of gap
seal was installed on Cessna 180s with decidedly mixed
results...though it was a factory engineered mod which (presumably)
thru testing showed benefits, many Cessna owners have faulted them as
the source of nasty manners during landings & takeoffs...I found a
current thread on the subject w/ the help of Mr. Google, and by chance
had a lengthy conversation w/ a 180 owner this weekend who is very
happy that he removed them.
> This would reduce the size of the gap with the flaps extended, does
> this have consequences?
I would think so, and not necessarily positive. I'd classify the
Europa flap as a "slotted flap" which is generally designed to allow
substantial airflow thru the slot which I believe is intended to
promote the attachment of the boundary layer to the upper surface of
the flap...a good thing, no?
I would think that if the compressible flap gap seal which John
Lawton recommends was sliced from a circular rod of closed cell foam
(known as "backer rod" and used in the US for sealing the joint
between concrete and the sill plate of a wood wall) would have minimal
disruption of airflow thru the slot.
As you can read from my use of terms that I have only a fuzzy
awareness of this stuff, so take my comments with a grain of salt.
Fred
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