On Tuesday, December 17, 2013 8:45:29 AM UTC-7, kirk.stant wrote:
On Tuesday, December 17, 2013 8:56:35 AM UTC-6, wrote:



I then had Rex install the locally sourced airvent that is placed on the top of the fuselage just behind the canopy. Immediately quieter cockpit. Now I could feel air moving past my face when the forward vent was opened.. The canopy airvent stays closed right up to redline.







Did it improve my L/D by 10 points? Can't tell you.



I'm seriously considering installing one on my LS6b this winter - where did you get yours from?



Kirk

66

This was discussed many, many years ago. As if you feel that with your cockpit vent open and your final glide is so critical, what Holighaus simply recommended was to "Close" your cockpit vent and stop doing final critictal glides! Whats needed is the cockpit air to "vent" and whats required to vent "all" that air. What one needs to also understand is that the fuselage is a main part of the structure strength for the prevention of flutter. It is highly suggested before cutting holes to discuss this with the manufacture.

On that DG vent, at the Worlds, it was used as a mental advantage ploy. As when statements were made that it "speeds up the exiting air" meant major discovery of a perpetual motion" had been discovered. Later, it was found as such and no performance increase was found. A sales ploy, well, maybe just another needed vent as getting "ALL" the air to exit takes more vents than gliders use. Also, exhausting air thru the wings has always been difficult to totally seal. This might help with that if used correctly.

A definition is needed on this:" Perpetual motion describes motion that continues indefinitely without any external source of energy.[2] This is impossible in practice because of friction and other sources of energy loss.[3][4][5] Furthermore, the term is often used in a stronger sense to describe a perpetual motion machine of the first kind, a "hypothetical machine which, once activated, would continue to function and produce work"[6] indefinitely with no input of energy. There is a scientific consensus that perpetual motion is impossible, as it would violate the first or second law of thermodynamics.[4][5]

Yes, JS did use a ASH 26 fuselage and agreements were then reached with AS on the continued use(my sources are very reliable on this). I have also used a very expensive manometer that reads down to a .0001 pressure difference.. I will say I wish I had my money back on that test. But my exhaust air has "more" than one way out as it escapes the aft area. If you load up your "behind head area" with all sorts of stuff, you are restricting the airflow out.

At least with the "new Vent" it stops you from doing this and this may be whats needed as a enlightenment for many folks and a few folks make a few more bucks!

Best, FWIW, #711.