Date: Mon, 01 Aug 94 09:01:53 CDT
Sender: Vanagon Mailing List <vanagon@vanagon.com>
From: Joel Walker <JWALKER@ua1vm.ua.edu>
Subject: aerodynamics: kinetically induced noise due to boundary layer separation
uhhhh ... my experimentation has conclusively shown that it is the mirrors
that cause the noise at the front vent windows. :) and opening the vent
windows disrupts the flow around the mirror and thus quietens the noise.
this can be noticed on the buses with the power mirrors (which are somewhat
more aero shaped and a little less noisy. also check the mirrors on the
eurovan ... less area between the mirror and the body = less noise)
likewise the front vent (dash control) being open DEcreases the stagnant
atmospheric/barometric/hypobaric pressure (stagnation pressure zone) at
the front of the vehicle ... by bleeding off pressure, the noise is
decreased. the crappy job vw did of sealing that big vent up there doesn't
help. mine has been blowing little pieces of the gasket out for a couple of
years now. and i don't see any way to replace it without removing the whole
dash! :( <yes. i looked. you can't get there from the outside>
for a good cement to re-attach those drip rail covers (which, in case anyone
is interested, come also in BLACK plastic and shouldn't cost more than about
$8 each), get some 3M General Purpose Adhesive Remover (to clean up the old
stuff), and some 3M Super Weatherstrip Adhesive (the black stuff). it works
real well.
7-seater jump-down turn-around: i did that in my old 80 bus (reverse the
middle seat), but never drilled the holes ... just used it for carrying some
junk. it works pretty good, but i recall something about an armrest banging
into the wall. ?? did the old vinyl middle seats have an armrest for the
person next to the sliding door? can't recall. monday. :(
once upon a time, in my old 71 bus, i took the middle seat out, and put it
back in 90 degrees to the 'right position', over under the side window. it
wasn't tied down (and nobody sat in it), but it worked pretty neat for just
sitting. then we loaded up the furniture and i took off for virginia. had
to go through a toll-tunnel in mobile (way back when) and the cretin in the
toll-booth tried to charge me a truck rate cause i didn't have a middle seat
and was hauling furniture! i told him i wasn't gonna pay it (as i was
properly licensed as a station wagon) and we went round and round for a while.
when i finally got really pissed and demanded to see his supervisor, he
shutup and let me through at the passenger car rate. :) i think the twenty
or so cars piling up behind me had something to do with it as well.
oh, god. another monday. :(
joel