Hi Gang I down loaded the profilli software as suggested by steve J - brilliant - I will send the owner the $10 or whatever to get the full version.
I figured steve was talking through his neck - P51 wing sectrion - oh yeah - well I the P51 section is there and I did the comparrison he reccomended - P51 against the AS 5046 - amazing similarity. Then came the discussion from the airfoil boffs about the cusp (tuck???). Take the cusp out of a 4046 and you have a P51 root section - I will do it like that. Ron > > > I am interested in the strange "tuck" underneath the trailing > > > edge - the last few mm seem to droop down leaving a > > > concave area right at the back (underneath). > >That trailing edge cusp does several different things. When comparing to a >related airfoil without the cusp, the coefficient of lift will be higher at >a given angle of attack, the pitch moment will be more negative, and the >boundary layer separation will tend to stay closer to the trailing >edge. The maximum coefficient of lift of the two different airfoils will >be approximately the same, but the cusped airfoil will reach it at a lower >angle of attack. All of these parameters are compromises that affect the >overall design of the airplane. > >It can be an acceptable airfoil for a wing root but will be a poor choice >for a control surface. Aileron control forces will be high. It is a less >than optimum choice for an airfoil that is intended to be laminar over a >wide range angle of attack. > > >Don Reid - donreid "at" erols.com >Bumpass, Va > >Visit my web sites at: > >AeroFoil, a 2-D Airfoil Design And Analysis Computer Program: >http://www.eaa231.org/AeroFoil/index.htm > >KR2XL construction: http://users.erols.com/donreid/kr_page.htm >Aviation Surplus: http://users.erols.com/donreid/Airparts.htm >EAA Chapter 231: http://eaa231.org >Ultralights: http://usua250.org >VA EAA State Fly-in: http://vaeaa.org >_______________________________________ >to UNsubscribe from KRnet, send a message to krnet-le...@mylist.net >please see other KRnet info at http://www.krnet.org/info.html _________________________________________________________________ Tax headache? MSN Money provides relief with tax tips, tools, IRS forms and more! http://moneycentral.msn.com/tax/workshop/welcome.asp
