Wind Deflectors - Fiberglass RV


Reply
 
Thread Tools Search this Thread Display Modes
 
Old 06-14-2009, 05:15 PM   #1
Senior Member
 
Roger C H's Avatar
 
Name: Roger
Trailer: 2009 Trillium 1300 "Homelet"/2014 Subaru Outback "Rosie"
Washington
Posts: 2,172
Registry
Unhappy

Has anyone had any experience with wind deflectors?

http://www.jcwhitney.com/Roof-Top-Wind-Def...s/600001569.jcw

Are they worth the money?
__________________

__________________
A charter member of the Buffalo Plaid Brigade!

Whether you think you can or think you can't, you're right.
Roger C H is offline   Reply With Quote
Old 06-14-2009, 05:57 PM   #2
Senior Member
 
Trailer:
Posts: 787
This isn't personal experience, but some tests were conducted back in the 80s when deflectors like this were popular in Europe - these were proper full scale wind tunnel tests by aerodynamicists, rather than claims by manufacturers.

These drawings show the actual profiles of the three test cases - you may recognise the outline of the then Volkswagen Passat car:


Click image for larger version

Name:	spoiler_drag.jpg
Views:	68
Size:	22.2 KB
ID:	20941


In the first and last cases, the drag coefficient is 0.53 while in the middle case with a deflector it is 0.45 - that's a solid 15% drag reduction and so you would expect a fuel economy improvement of at least 10%.

The other part of these tests was to measure the aerodynamic lift on the front of the trailer, as a reduction in hitch weight at 50mph. In the first case, the hitch weight reduced by 75 pounds which, compared to a typical low European hitch weight (typically 100-150 pounds), is very significant.

With the roof deflector, the reduction was 70 pounds, but with a slope-fronted trailer and no deflector, there was no reduction in hitch weight and so no reduction in trailer stability - this is the main reason why you will find a sloping front on just about every European trailer made since then.

Of course these results don't compare directly to typical American towing practice, but it does show categorically that deflectors can work well in the right conditions.

Andrew
__________________
Andrew Gibbens is offline   Reply With Quote
Reply


Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Wind Power Perry Mac Donald General Chat 10 04-24-2010 09:04 PM
Wind Power Tamid Electrical | Charging, Systems, Solar and Generators 9 01-23-2010 04:28 PM
Wind deflector Richard LP Classified Archives 0 08-15-2009 03:37 PM
Wind Power Lainey Care and Feeding of Molded Fiberglass Trailers 2 05-18-2009 10:14 PM
The wind Gina D. Problem Solving | Owners Helping Owners 10 02-16-2006 12:04 AM

» Upcoming Events
No events scheduled in
the next 465 days.
» Virginia Campgrounds

Reviews provided by


Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -6. The time now is 03:47 AM.


Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.