A aviation & planes forum. AviationBanter

If this is your first visit, be sure to check out the FAQ by clicking the link above. You may have to register before you can post: click the register link above to proceed. To start viewing messages, select the forum that you want to visit from the selection below.

Go Back   Home » AviationBanter forum » rec.aviation newsgroups » Soaring
Site Map Home Register Authors List Search Today's Posts Mark Forums Read Web Partners

varios not using a total energy probe



 
 
Thread Tools Display Modes
  #21  
Old April 25th 04, 11:24 PM
Martin Gregorie
external usenet poster
 
Posts: n/a
Default

On Fri, 23 Apr 2004 09:45:33 +1000, Mike Borgelt
wrote:

On Wed, 21 Apr 2004 11:57:40 +0100, Martin Gregorie
wrote:

On Wed, 21 Apr 2004 10:02:05 +1000, Mike Borgelt
wrote:

Generally pitot and static probes/ports are much more sensitive to
sideslip than are good TE probes.(Good TE probe = Irving type two hole
probe )

Mike, just a quick question:

My ASW-20 is fitted with a fin mounted Irving-type TE probe except
that it only has a single hole in place of the usual two holes. What
advantages would there be to swapping it for a two-hole version?



Martin,

While I have seen wind tunnel data that suggests that the suction
around the rear 180 deg of the tube is constant there do seem to be
variations and the two hole probe may be less sensitive to sideslip.

Also:

Many years ago now just after the Irving probe design became available
I built one in 1/4" tube and one in 3/16" tube and a Nicks(single hole
type)in 3/16" as per Oran Nicks drawings. I then flew my Mini Nimbus
with a second ASI connected to probe and pitot. I checked the two
instruments against each other and applied static system corrections
to the readings of the normal ASI and reckoned I could get down to an
error band of +/- 4%.

I had had a feeling that the Nicks tube was under compensating and the
test showed it to be short of suction by 20% and a little more at low
speeds.

The Irving probe made per Irving was within my error band and the
3/16" Irving was a little short on suction getting worse at low speeds
leading me to conclude that there may be a Reynolds number effect for
the low airspeeds and smaller diameter tubes.

Interestingly Nicks recommended the hole 2 x tube diameters from the
end and Irving said 1.5

Current Irving type tubes have settled on about 1.67 as the hole
distance from the end and the holes are closer together than on the
original Irving design and 6mm or 1/4" tube is used.

Mike Borgelt


Thanks, Mike. That's exactly what I wanted to know.

--
martin@ : Martin Gregorie
gregorie : Harlow, UK
demon :
co : Zappa fan & glider pilot
uk :

 




Thread Tools
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

vB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
Not to sound like an F-22 cheerleader but I thought this was interesting. . . Scott Ferrin Military Aviation 96 June 5th 04 04:24 PM
"I Want To FLY!"-(Youth) My store to raise funds for flying lessons Curtl33 General Aviation 7 January 10th 04 12:35 AM
Cleaning a 3-way TE probe Jack Glendening Soaring 37 November 5th 03 07:45 PM
I wish I'd never got into this... Kevin Neave Soaring 32 September 19th 03 12:18 PM
Question of the Day M B Soaring 16 September 10th 03 07:30 AM


All times are GMT +1. The time now is 01:19 PM.


Powered by vBulletin® Version 3.6.4
Copyright ©2000 - 2024, Jelsoft Enterprises Ltd.
Copyright ©2004-2024 AviationBanter.
The comments are property of their posters.