Chris,

 

Dittos.  Didn't Bob Belshe say he eventually retained the vortex generator only forward of the ailerons with better low speed control with them and less reduction in cruise speed.  If ya add gap seals ya can get the cruise speed back and even increase control surface aukthority..............

 

Grayhawk

 

Being somewhat interested in aircraft efficiency, two quotes from the VG website jumped out at me.

On the Lancair page:

" A 10 knot reduction in the stall speed; much better low speed handling and no reduction in the cruise speed."

Then on the FAQ page:

" At maximum power, you may experience a 0-4 mph reduction, but this depends on the particular aircraft. At normal cruising speed there is no noticeable reduction. "

For me maximum power typically is cruise power.  The speed loss will tend to be on the higher side in a low drag airframe.

VGs locally energize the boundary layer to keep the flow attached.  This takes energy. Unfortunately a nice laminar flow section is turned into a partially turbulent flow wing. Everything is a trade-off.

A previous link on the LML to Bob Belshe's 235 VG mod also reported a reduction in cruise speed of a couple knots.

Here is another link to a flight test report of a Bonanza with a VG upgrade.

http://www.nar-associates.com/technical-flying/vortex/Vgs_cruise_wide_screen.pdf

Chris Zavatson

N91CZ

360std

www.N91CZ.net

Sent from my spiffy iPad

On Jun 4, 2013, at 3:55 AM, Rob Murawski <rob@robmurawski.com> wrote:

Nice info on the VG's!  I've been contemplating whether to install the extended wingtips on my 360 MkII, now it looks like I have another option to reduce the stall speed.  Assuming I even need that.

This doesn't make the decision-making process any easier.

-Rob

Lancair 360MkII

15% Complete

Pittsburgh, PA

From: PETER WILLIAMS <peterpawaviation@hotmail.com>
Reply-To: Lancair Mailing List <lml@lancaironline.net>
Date: Tuesday, June 4, 2013 7:42 AM
To: <lml@lancaironline.net>
Subject: [LML] VORTEX GENERATORS

HI THERE

here is the link for vortex generator kits for Lancair aircraft

http://www.pnwaero.com/Lancair.htm

i was very happy with the company and with the results

peter williams

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