vgstol(at)bigpond.net.au
Guest
|
 Posted: Thu May 13, 2010 2:06 am Post subject: 701 Top Window 7F19-1 bubble for more headroom |
 |
|
I really don't think you have to worry about disrupting the airflow to the tail by adding an airfoil over the cabin top. Tuft testing that we have done show that the cabin top of the 701 stalls completely at about 46kts and the airflow becomes totally turbulent, while on the Savannah with the full airfoil of the wing carry-through, the airflow is still attached and smooth flow right down to 26kts indicated. The Savannah has much better elevator authority than then 701, right down to stall speed. Not only is it a smoother airflow over the cabin for less drag, it's also generating lift right down to that speed, while the 701 cabin top has lost lift much earlier. We tried adding a partial airfoil over the cabin top, stuck down temporarily with duct tape. Just at lift-off speed the trailing edge ripped the duct tape loose and the panel flapped wildly and somewhat alarmingly! You know how well duct tape holds, so this shows how much lift was regained by that partial airfoil.... So Hans is planning to build a permanent airfoil up there, (it's only that he's been pretty slack lately in his retirement...). Can't really do a full airfoil due to the angle of the windshield, etc, but anything that will ease that abrupt corner at the top of the windshield and add curvature instead of the flat surface will be an improvement. But it must be securely installed to cope with the lift generated......
JG
On Thu, May 13, 2010 at 2:53 PM, dons701 <burdon1(at)comcast.net (burdon1(at)comcast.net)> wrote:
[quote] --> Zenith701801-List message posted by: "dons701" <burdon1(at)comcast.net (burdon1(at)comcast.net)>
Hi Kevin, I was thinking along the same lines, more head room and to carry the curvature of the windshield through the top panel. My concerns were to not disrupt the prop blast to the tail too much and possibly add more to the wing area. Thanks for the picture
--------
Zenith 701 #76120
Jabiru 2200A #2456 67 hours
Sensenich Wood 64-PJ-36 Prop
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=297562#297562
===========
-List" target="_blank">http://www.matronics.com/Navigator?Zenith701801-List
===========
http://forums.matronics.com
===========
le, List Admin.
="_blank">http://www.matronics.com/contribution
===========
[b]
| | - The Matronics Zenith701801-List Email Forum - | | | Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:
http://www.matronics.com/Navigator?Zenith701801-List |
|
|
|
Get Email Distribution Too!
FAQ
Search
Memberlist
Usergroups
Register
Profile
Log in to check your private messages
Log in
