X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Sender: To: lml@lancaironline.net Date: Mon, 07 Oct 2013 13:37:09 -0400 Message-ID: X-Original-Return-Path: Received: from nm23-vm2.bullet.mail.gq1.yahoo.com ([98.136.217.81] verified) by logan.com (CommuniGate Pro SMTP 6.0.7) with ESMTPS id 6505629 for lml@lancaironline.net; Mon, 07 Oct 2013 12:48:07 -0400 Received-SPF: none receiver=logan.com; client-ip=98.136.217.81; envelope-from=dudewanarace@yahoo.com Received: from [98.137.12.56] by nm23.bullet.mail.gq1.yahoo.com with NNFMP; 07 Oct 2013 16:47:33 -0000 Received: from [98.137.12.249] by tm1.bullet.mail.gq1.yahoo.com with NNFMP; 07 Oct 2013 16:47:32 -0000 Received: from [127.0.0.1] by omp1057.mail.gq1.yahoo.com with NNFMP; 07 Oct 2013 16:45:45 -0000 X-Yahoo-Newman-Property: ymail-3 X-Yahoo-Newman-Id: 48814.29564.bm@omp1057.mail.gq1.yahoo.com Received: (qmail 46206 invoked by uid 60001); 7 Oct 2013 16:45:44 -0000 DomainKey-Signature:a=rsa-sha1; q=dns; c=nofws; s=s1024; d=yahoo.com; h=X-YMail-OSG:Received:X-Rocket-MIMEInfo:X-Mailer:Message-ID:Date:From:Reply-To:Subject:To:MIME-Version:Content-Type; b=rPuYuf727dhcm9xZF/4MCvmFmBFj3g1eGdUUeqycRfWR2H8dryCY6BRbbqNMllDe7KOpJCH0fumkhWUz0uBnSa40kZdvWoeCyyAO6R+xDcciFukX9FW/s21Zs6FktSQ1AClsATtSqGCjU6V70dzE67XVT7HPJWi5r+CJufll/qE=; X-YMail-OSG: LXVzclUVM1n9OFMnMvxTJOiiPlPtWRIRyta73lg0riJSHBV OW4d7AmSf4JWg4teI1YSSey3rgqhpCOYCxxnK76TpOHxlxYXwETChoTqEkOA DB679bHmC7UgLaD0_GsQljHv0SrCaYF2EEYBZFL7JqHXIYU5o4d9UKVYPTuv Z3Lpvkw3.gfZNil.UauWPnvC6ZcQTAPMNtZtaU3w7.ulVJxgdVYwFZlRz_cx rizHjvMyun1_wduKZUNvE06nKACF6Cm8Y9QlXVksYkX.vGZo_PbpT9r42wGW DyDRZ21T_iT8DpDcYMZe0Ww1PjrJoO23f3RljFc5Igl1iwbUHBhEG_DnqmgP J8rwIXfGODBMbVly_zIxC.wDqaZw4s_stV2_n4T2dS6wjKcfBjHxZAZwDLXQ wWnL.00Wmv0awz2iiKfZGWeXgL.cq4U465S25pg43dh19CAYJZ0fK8c9pVff mIdPViqD9ntRll1.Qnx9A0qHDVCRGV.dhC8Ka74_YeYRH.NWmwmFBRKNgFJC opsY.bS66iTprseLBArANn6xmG.fJ1Yu8vQC7Uw7kV8LafNBkJqKHV5s_8uz teKPY1aLjuVDlirJENUdb9MXGd_kULGBUsRDzsoewKgaPlyHAA5HVfRspMeI TQYIDDhYrDHCo77z44ACPLK5OwnybpKp9nko.fRqWIhKoV49HMfPsa1T6yrE id69YDnbOauf6BiWOl.HuiZNI9qemKrfyDW8q44tMZxWju9xoGd4YjMGeQLF 0tMd1Z5ZXcEClJMWW9_kH7dLW5F6TA_awCQshCeszMKnZrZu8UV8gGQT0gib x7BVi.c.jrNGKqEWBCUwOz13vdQ-- Received: from [24.2.15.88] by web120905.mail.ne1.yahoo.com via HTTP; Mon, 07 Oct 2013 09:45:43 PDT X-Rocket-MIMEInfo: 002.001,UmVhZGVycywKSSBzd2l0Y2hlZCB0aGUgdG9waWMgYXMgdGhlIGNvbnZlcnNhdGlvbiB3YXMgZ2V0dGluZyBhIGJpdCBsb3N0IGluIHRoZSAnb3RoZXInIHRocmVhZC4gwqBJIGNvcGllZCBteSBvcmlnaW5hbCBwb3N0IGF0IHRoZSBib3R0b20gb2YgdGhpcyBwb3N0LiDCoEkgYWRkcmVzc2VkIHNvbWUgcXVlc3Rpb25zIGluZGl2aWR1YWxseSBub3QgcmVhbGl6aW5nIGl0IHdvdWxkbid0IGFuc3dlciBmb3IgZXZlcnlvbmUuIMKgU28sIEknbGwgaGl0IHRoZSBoaWdobGlnaHRzIGhlcmU6CgpTdGFiaWxpdHkgYW4BMAEBAQE- X-Mailer: YahooMailWebService/0.8.160.587 X-Original-Message-ID: <1381164343.44667.YahooMailNeo@web120905.mail.ne1.yahoo.com> X-Original-Date: Mon, 7 Oct 2013 09:45:43 -0700 (PDT) From: dudewanarace@yahoo.com Reply-To: dudewanarace@yahoo.com Subject: Unleashed Flap/Fuse Mods X-Original-To: Lancair Mailing List MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="1517483800-975916103-1381164343=:44667" --1517483800-975916103-1381164343=:44667 Content-Type: text/plain; charset=iso-8859-1 Content-Transfer-Encoding: quoted-printable Readers,=0AI switched the topic as the conversation was getting a bit lost = in the 'other' thread. =A0I copied my original post at the bottom of this p= ost. =A0I addressed some questions individually not realizing it wouldn't a= nswer for everyone. =A0So, I'll hit the highlights here:=0A=0AStability and= general oddness=0AUnleashed is a small tail 360 that has been converted to= electric trim. =A0The trim tab extends aft of the trailing edge of the ele= vator, it is not a section of the elevator like most trim tabs. =A0Combine = that incorrect angle of incidence and a varying tab effectiveness and you e= nd up with a smaller trim window than most. =A0By that I mean, a smaller sp= eed range where you are able to trim to a neutral stick. =A0That range is a= bove a full flap condition, and below top 5% of the speed range. =A0The bot= tom end doesn't bother me at all, the top end gets annoying to say the leas= t. =A0A poor mans solution for the top end of the envelope is to pull the f= laps out of reflex a few degrees. =A0Doing this gets you back in the trim w= indow, barely. Removing the cusp in the flaps did change these results. =A0= It now requires you to pull even more flaps out of reflex to get it trimmed= . =A0Hopefully this will be resolved if/when I correct the horizontal angle= of incidence.=0A=0AFlap Cusp Removed=0AThe common question is how much fas= ter. =A0Well, it is almost not measurable at this point. =A0Maybe a few mph= , but hard to tell. =A0I have reached the limit of this propeller so it cou= ld be false indication of potential speed gains. =A0Meaning any aero improv= ements may not show up just because the propeller is no longer pulling. =A0= What I do notice is the speed it accelerates has been improved. =A0Also, it= appears to bleed less energy under G's. =A0As Chris pointed out, this is p= robably due to the better lift coefficient under G's at these speeds. =A0Th= us, removing the cusp giving the wing less camber was probably an improveme= nt. =A0The "on track" report from Dave Morss was that it seemed to accelera= te out of the corners much better than it used to. =A0If anybody had a good= view of that, he did! =A0See video below=0Ahttp://youtu.be/iegd6ylVHI4=0A= =0AAlthough he got me on Sunday.. damn it!=0A=0ABeluga Belly Fuselage Mod= =0AFirst, this represents the change in shape. =A0Rather drastic:=0Ahttp://= www.n54sg.com/wp-content/uploads/2013/07/teaser_beluga.jpg=0A=0AWhat starte= d this mod was an odd thing that would happen at high indicated airspeeds a= nd high propeller rpm. =A0 The vertical airspeed indicator would start to s= wing wildly from +500 to -500 in about a 2 to 3 second interval. =A0My stat= ic ports are in the stock location just below the rear windows, on each sid= e. =A0I suspected this false indication was caused by a rather drastic pres= sure change happening in that area. =A0I didn't have any pre-modification t= uft pictures, only word of mouth from a friend in formation, sadly not fast= enough to cause the wild swing in VSI. =A0But, from word of mouth, the tuf= ts in that area and aft of the wing were angled up rather high. =A0Somethin= g in the order of 30 to 45 degrees.=0A=0ANow, my number 1 rule, cheat first= . =A0Plenty of super fast legacies have made a modification to this area. = =A0The idea being to keep the fuselage perpendicular to the wing from its w= idest point to 5% of the chord aft of the trailing edge, then blend it in. = =A0Soooo let the wing do its lift thing, before you turn it in to the fusel= age. =A0How you make that turn is rather critical, and I may have done it d= ifferently now that I know more. =A0But, from this pic you can see the tuft= s for the entire side are nowhere near 45 degrees up, so I have changed the= relative flow for the entire area.=0Ahttp://www.n54sg.com/images/tuft_test= _08.jpg=0A=0ANow, for the record, I was in a hurry and stuck those on in ab= out 2 min. =A0It lacks the resolution I would really want to see and yellow= string was far from ideal. =A0Also, the last two on the upper row were sta= rting to peel off so the tape was screwing with their indication. =A0I'll d= o it again now that I have more time and would love to compare to a "stock"= 360 sometime.=0A=0AMoral of the story, LOTS of work, and it may not be wor= th it at the slower speeds. =A0The faster I go, the more important it may b= e. =A0Again I can't give what I think is a realistic mph gain, as the prope= ller could be limiting the results.=0A=0AFor some interesting info on the c= oncepts check out this image. =A0This a project out of Brazil called Anequi= m. =A0The Magenta area is laminar flow. =A0The difference in the left desig= n and the right design is a change in the canopy! =A0Notice the diferrence = in laminar flow near the wing root.=0Ahttps://fbcdn-sphotos-a-a.akamaihd.ne= t/hphotos-ak-ash2/483140_470387089689885_1079016313_n.jpg=0A=0AIt all works= together.=0A=0ATom McNerney=0Awww.N54SG.com=A0=0A=0A=0A=0AOriginal Post=0A= =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0= =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0=A0=0AReade= rs,=0AI have been watching this conversation with interest. =A0I have some = odd experiences with stability in my small tail 360 that was improperly bui= lt (not by me). =A0Geez, that is going to hurt resale.. haha=0A=0AAnyway, I= have been waiting to comment as it will just fog the data that has been pr= esented given my totally odd arrangement and lack of any real data. =A0All = of my 'data' is seat of the pants, thus not worth mentioning. =A0But, figur= ed I could expand on an envelope probably few have visited just for interes= ting reading.=0A=0AThis is my elevator angle with the airplane in a forward= C.G. condition (header fuel only, single pilot), flaps in reflex and, well= , going as fast as an RV-7 will go in formation. :)=0Ahttp://www.n54sg.com/= images/tuft_test_08.jpg=0A=0A=0ASo, this problem poses a few issues.=0AFirs= t, this is obviously drag, probably a measurable amount thus for me the dri= ving force behind correcting it one day. =A0Second is the available elevato= r travel. =A0If you read the manual, I have the correct amount of up / down= elevator travel. =A0But, if the photo is my starting point, it means I hav= e much less up, and way too much down available to use. =A0The important pa= rt being the elevator up while in the flare. =A0Given a forward C.G. and a = huge amount of flaps, this can be an issue. (ask me how I know...)=0A=0ANex= t I would like to mention that not all small tails trim the same. =A0Some u= se a spring system to bias the entire elevator. =A0Others use trim tabs. = =A0I have a tab that due to its placement and odd elevator deflection has a= limited functional envelope. =A0Another driving force to change incidence.= =0A=0ANow the often obvious question people ask is why haven't I fixed it y= et. =A0Well, because the job of fixing it is going to totally suck, and I w= anted it to be the last thing I do as my other aerodynamic changes may affe= ct the angle of incidence. =A0This brings me to the next subject, what I ha= ve changed.=0A=0ASo I have this airplane going faster than most and figured= why stop now.. I made a rather drastic change that some call the beluga be= lly. =A0It has been done to a few Legacys that race with varied application= s of the same idea. =A0Those familiar with the 320/360 fuselage will notice= it in this picture:=0Ahttp://www.n54sg.com/images/tuft_test_04.jpg=0A=0AI'= m working on a write up for my website detailing the project and its purpos= e and will have that posted sometime soon. =A0But, I will report that this = did change the downwash on my horiztonal and did change my required angle o= f incidence. Hence, I'm glad I waited to change that. =A0It actually requir= es less up elevator than it did before so less negative incidence. =A0The g= eneral theory is I have corrected some flow around the fuselage thus making= the entire horizontal a bit more effective. =A0Some modified Legacys exper= ienced something similar. =A0I only wish it would have corrected it more! = =A0I now know more about this mod and maybe would have applied it different= ly. =A0Just not sure I'm willing to do the work again for unknown gains.=0A= =0AThe other aerodynamic change I made (that relates to the original stabil= ity post) is I removed the cusp from the bottom surface of my flaps as sugg= ested in a book about GA airfoils by Harry Riblett. =A0Below is a simplifie= d version of his drawing. =A0(Not accurate, just for explanation purposes) = =A0The solid black is the modification.=0Ahttp://www.n54sg.com/images/Flap_= Drawing.jpg=0A=0ASo, what I have done to the camber of the wing is a bit od= d I suppose, but it was odd to start with. =A0Keep in mind, the 320 / 360 a= ilerons already have this modification. =A0I didn't get the 10 kts I though= t I would. =A0(Aren't all mods worth 10 kts? haha) =A0But, it is a differen= t airfoil. =A0Stall was no different, but the pitch force did increase with= flaps extended. =A0Not a bad thing in my opinion. =A0Overall it is hard to= explain, it is a different wing, just can't pinpoint how.=A0=0A=0AIn the e= nd I think I have made the airplane aerodynamically better, but I have move= d the problem. =A0It seems with just a little bit cleaner airplane I ran in= to the limit of the propeller. =A0Previously more rpm always netted more s= peed. =A0Now the top 250ish rpm doesn't do much at all. =A0Total bummer! = =A0Having to learn a lot more about propellers than I ever thought I would = now...=0A=0AResults of my airplane at Reno this year:=0AQualifying: 268.272= mph=0ASport Medallion: 1st 261.906 mph (only 2600 rpm!)=0AHeat 1C: 3rd 268= .300 mph=0AHeat 2C: 2nd 265.030 mph=0AHeat 3C: 2nd 266.717 mph=0ABronze Rac= e: 2nd 266..944 mph=0A=0A=0AI have some really cool video from my helmet/da= sh cameras, just trying to get it all edited. =A0Hear is a teaser of some V= ERY close racing with Dave Morss in his Legacy:http://youtu.be/iegd6ylVHI4= =0ABest to watch in full screen in HD. =A0Keep in mind, objects in a wide a= ngle lens are closer than they appear! haha=0A=0ATom McNerney=0Awww.N54SG.c= om --1517483800-975916103-1381164343=:44667 Content-Type: text/html; charset=iso-8859-1 Content-Transfer-Encoding: quoted-printable
Readers,
I switched the top= ic as the conversation was getting a bit lost in the 'other' thread.  = I copied my original post at the bottom of this post.  I addressed som= e questions individually not realizing it wouldn't answer for everyone. &nb= sp;So, I'll hit the highlights here:

Stability and general oddn= ess
Unleashed is a small tail 360 that has been converted to electric= trim.  The trim tab extends aft of the trailing edge of the elevator,= it is not a section of the elevator like most trim tabs.  Combine tha= t incorrect angle of incidence and a varying tab effectiveness and you end = up with a smaller trim window than most.  By that I mean, a smaller sp= eed range where you are able to trim to a neutral stick.  That range i= s above a full flap condition, and below top 5% of the speed range.  T= he bottom end doesn't bother me at all, the top end gets annoying to say th= e least.  A poor mans solution for the top end of the envelope is to p= ull the flaps out of reflex a few degrees.  Doing this gets you back i= n the trim window, barely. Removing the cusp in the flaps did change these = results.  It now requires you to pull even more flaps out of reflex to= get it trimmed.  Hopefully this will be resolved if/when I correct the horizontal angle of incidence.

Flap Cusp Removed
Th= e common question is how much faster.  Well, it is almost not measurab= le at this point.  Maybe a few mph, but hard to tell.  I have rea= ched the limit of this propeller so it could be false indication of potenti= al speed gains.  Meaning any aero improvements may not show up just be= cause the propeller is no longer pulling.  What I do notice is the spe= ed it accelerates has been improved.  Also, it appears to bleed less energy under G's.  As Chris pointed out, this is probably due to the = better lift coefficient under G's at these speeds.  Thus, removing the= cusp giving the wing less camber was probably an improvement.  The "o= n track" report from Dave Morss was that it seemed to accelerate out of the= corners much better than it used to.  If anybody had a good view of t= hat, he did!  See video below
Although he got me on Sunday.. damn= it!

Beluga Belly Fuselage Mod
First, this represents the change in shape.  Rather dra= stic:
http://www.n54sg.com/wp-content/uploads/2013/07/te= aser_beluga.jpg
What star= ted this mod was an odd thing that would happen at high indicated airspeeds and high pr= opeller rpm.   The vertical airspeed indicator would start to swing wi= ldly from +500 to -500 in about a 2 to 3 second interval.  My static p= orts are in the stock location just below the rear windows, on each side. &= nbsp;I suspected this false indication was caused by a rather drastic press= ure change happening in that area.  I didn't have any pre-modification tuft pictures, only word of= mouth from a friend in formation, sadly not fast enough to cause the wild = swing in VSI.  But, from word of mouth, the tufts in that area and aft= of the wing were angled up rather high.  Something in the order of 30= to 45 degrees.

Now, my= number 1 rule, cheat first.  Plenty of super fast legacies have made = a modification to this area.  The idea being to keep the fuselage perp= endicular to the wing from its widest point to 5% of the chord aft of the t= railing edge, then blend it in.  Soooo let the wing do its lift thing,= before you turn it in to the fuselage.  How you make that turn is rat= her critical, and I may have done it differently now that I know more. &nbs= p;But, from this pic you can see the tufts for the entire side are nowhere = near 45 degrees up, so I have changed the relative flow for the entire area= .
No= w, for the record, I was in a hurry and stuck those on in about 2 min. &nbs= p;It lacks the resolution I would really want to see and yellow string was = far from ideal.  Also, the last two on the upper row were starting to = peel off so the tape was screwing with their indication.  I'll do it a= gain now that I have more time and would love to compare to a "stock" 360 s= ometime.

Moral of the story, LOTS of work, and it may not be = worth it at the slower speeds.  The faster I go, the more important it= may be.  Again I can't give what I think is a realistic mph gain, as = the propeller could be limiting the results.

For some interes= ting info on the concepts check out this image.  This a project out of Bra= zil called Anequim.  The Magenta area is laminar flow.  The diffe= rence in the left design and the right design is a change in the canopy! &n= bsp;Notice the diferrence in laminar flow near the wing root.
https://fbcdn-sphotos-a-a.akamaihd.net/h= photos-ak-ash2/483140_470387089689885_1079016313_n.jpg
It all works together.

Tom McNerney
www.N54SG.com = ;



Original P= ost
                &nbs= p;                     &n= bsp;                     =           
Readers,
I have b= een watching this conversation with interest.  I have some odd experience= s with stability in my small tail 360 that was improperly built (not by me)= .  Geez, that is going to hurt resale.. haha

Anyway, I have been waiting to comment as it will just= fog the data that has been presented given my totally odd arrangement and = lack of any real data.  All of my 'data' is seat of the pants, thus no= t worth mentioning.  But, figured I could expand on an envelope probab= ly few have visited just for interesting reading.

This is my elevator angle with the airplane in a forward C.G. condition (header fuel only, sin= gle pilot), flaps in reflex and, well, going as fast as an RV-7 will go in = formation. :)

So, this p= roblem poses a few issues.
First, this is obviously drag, probably a measur= able amount thus for me the driving force behind correcting it one day. &nb= sp;Second is the available elevator travel.  If you read the manual, I= have the correct amount of up / down elevator travel.  But, if the ph= oto is my starting point, it means I have much less up, and way too much do= wn available to use.  The important part being the elevator up while i= n the flare.  Given a forward C.G. and a huge amount of flaps, this ca= n be an issue. (ask me how I know...)


Now the often obvious question people ask is why h= aven't I fixed it yet.  Well, because the job of fixing it is going to= totally suck, and I wanted it to be the last thing I do as my other aerody= namic changes may affect the angle of incidence.  This brings me to th= e next subject, what I have changed.

So I have this airplane going fas= ter than most and figured why stop now.. I made a rather drastic change tha= t some call the beluga belly.  It has been done to a few Legacys that = race with varied applications of the same idea.  Those familiar with t= he 320/360 fuselage will notice it in this picture:
I'm working on a write up for my website detailing the project and its pur= pose and will have that posted sometime soon.  But, I will report that= this did change the downwash on my horiztonal and did change my required a= ngle of incidence. Hence, I'm glad I waited to change that.  It actual= ly requires less up elevator than it did before so less negative incidence.=  The general theory is I have corrected some flow around the fuselage= thus making the entire horizontal a bit more effective.  Some modifie= d Legacys experienced something similar.  I only wish it would have co= rrected it more!  I now know more about this mod and maybe would have = applied it differently.  Just not sure I'm willing to do the work agai= n for unknown gains.

The other aerodynam= ic change I made (that relates to the original stability post) is I removed= the cusp from the bottom surface of my flaps as suggested in a book about = GA airfoils by Harry Riblett.  Below is a simplified version of his dr= awing.  (Not accurate, just for explanation purposes)  The solid = black is the modification.
So, what I have done to the ca= mber of the wing is a bit odd I suppose, but it was odd to start with. &nbs= p;Keep in mind, the 320 / 360 ailerons already have this modification. &nbs= p;I didn't get the 10 kts I thought I would.  (Aren't all mods worth 1= 0 kts? haha)  But, it is a different airfoil.  Stall was no diffe= rent, but the pitch force did increase with flaps extended.  Not a bad= thing in my opinion.  Overall it is hard to explain, it is a differen= t wing, just can't pinpoint how. 
=
In the end I think I have made the= airplane aerodynamically better, but I have moved the problem.  It se= ems with just a little bit cleaner airplane I ran in to the limit of the propeller.  Previously more rpm always netted more speed.  Now t= he top 250ish rpm doesn't do much at all.  Total bummer!  Having = to learn a lot more about propellers than I ever thought I would now...

R= esults of my airplane at Reno this year:
Qualif= ying: 268.272 mph
Sport Medallion: 1st 261.906 mph (only 2600 rpm!)
Heat 1C: 3rd 268.300 mph
Heat 2C: 2nd 2= 65.030 mph
Hea= t 3C: 2nd 266.717 mph
Bronze Race: 2nd 266..944 mph

I have some really coo= l video from my helmet/dash cameras, just trying to get it all edited. &nbs= p;Hear is a teaser of some VERY close racing with Dave Morss in his Legacy:= http://youtu.be/iegd6ylVHI4
Best to watch in full screen in HD.  Keep in mind, ob= jects in a wide angle lens are closer than they appear! haha

Tom McNerney=
--1517483800-975916103-1381164343=:44667--