---------------------------------------------------------- Pietenpol-List Digest Archive --- Total Messages Posted Wed 02/18/04: 4 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 07:01 AM - Re: wind tunnel (Robert Haines) 2. 08:19 AM - Re: Re: wind tunnel (Gnwac@cs.com) 3. 09:34 AM - Re: Re: wind tunnel (bike.mike) 4. 12:41 PM - Re: Re: wind tunnel (Fred Weaver) ________________________________ Message 1 _____________________________________ Time: 07:01:08 AM PST US From: "Robert Haines" Subject: Pietenpol-List: Re: wind tunnel --> Pietenpol-List message posted by: "Robert Haines" Max - starting on my airplane is currently in the queue, it's right behind restoring my 1866 house (I had it lifted off the foundation and replaced the basement last winter) and my 1930 Model-A, and this last summer we had our second son (yea, my friends and family think I'm nuts). I've got my hands busy after hours. This wind tunnel thing is something I can sneak in on my lunch hour. More to the point, it's actually part of what I would consider my pre-building "homework" to an aircraft design that I'm sure I will modify. Until my after-work projects run their course, I'm doing OK flying 152's periodically, at least I'm flying. Chris - So if I added little bumps and dips on the 24" scaled wing section the test would then be valid? Otherwise, the information is meaningless? Please reread my previous post regarding error in testing, all testing has error. At 1/10 scale (I'm considering a wing section with a 6" cord) the surface irregularities due to rib stitching is too small to matter. The deformation of the skin between the ribs is a consideration, but you would have to be a fortune teller to be able to guess what that deformation is to any accuracy since the deformation changes under different speeds and angle of attack. Not to mention there are those who consider adding an aluminum or plywood wrap around the front edge to midigate this and this would then be another set of models. Gesh, I'm just trying to do something that would be helpful to the group. Respectfully, Robert Haines Du Quoin, Illinois ________________________________ Message 2 _____________________________________ Time: 08:19:25 AM PST US From: Gnwac@cs.com Subject: Re: Pietenpol-List: Re: wind tunnel Robert, Any help and information you can add to the Group would be helpful regarding the FC 10. Please continue. I would like to see what you come up with in the end. Greg Menoche Delaware ________________________________ Message 3 _____________________________________ Time: 09:34:41 AM PST US From: "bike.mike" Subject: Re: Pietenpol-List: Re: wind tunnel --> Pietenpol-List message posted by: "bike.mike" Robert, et al: What is it that you expect to learn by performing a wind tunnel test? If you want to enjoy the scientific lab work of building a model, setting up and running a test, and analyzing results, the wind tunnel is a great exercise that is fun in its own way. If, however, you want to learn how the Piet wing performs, in its full-scale, bug-smashed, real-life, application, there are thousands and thousands of hours of actual flight, reported by the thousands of Piet pilots of every possible skill level and scientific background who have built and flown this little beauty in every conceivable configuration and modification over the last 75 years. A wind tunnel test of any sort, even a full-scale airplane in a large section tunnel at Langley in Virginia or at Ames in California, is only going to give you an approximation of what is learned in actual flight. Enjoy your tunnel testing, but don't expect it to tell you anything usable that hasn't already been learned. Mike Hardaway (More hours in airplanes than on tunnels, but have enjoyed both for their own sakes.) ----- Original Message ----- From: Robert Haines Subject: Pietenpol-List: Re: wind tunnel > --> Pietenpol-List message posted by: "Robert Haines" > > Max - starting on my airplane is currently in the queue, it's right behind > restoring my 1866 house (I had it lifted off the foundation and replaced the > basement last winter) and my 1930 Model-A, and this last summer we had our > second son (yea, my friends and family think I'm nuts). I've got my hands > busy after hours. This wind tunnel thing is something I can sneak in on my > lunch hour. More to the point, it's actually part of what I would consider > my pre-building "homework" to an aircraft design that I'm sure I will > modify. Until my after-work projects run their course, I'm doing OK flying > 152's periodically, at least I'm flying. > > Chris - So if I added little bumps and dips on the 24" scaled wing section > the test would then be valid? Otherwise, the information is meaningless? > Please reread my previous post regarding error in testing, all testing has > error. At 1/10 scale (I'm considering a wing section with a 6" cord) the > surface irregularities due to rib stitching is too small to matter. The > deformation of the skin between the ribs is a consideration, but you would > have to be a fortune teller to be able to guess what that deformation is to > any accuracy since the deformation changes under different speeds and angle > of attack. Not to mention there are those who consider adding an aluminum > or plywood wrap around the front edge to midigate this and this would then > be another set of models. > > Gesh, I'm just trying to do something that would be helpful to the group. > > > Respectfully, > > Robert Haines > Du Quoin, Illinois > > ________________________________ Message 4 _____________________________________ Time: 12:41:12 PM PST US From: "Fred Weaver" Subject: Re: Pietenpol-List: Re: wind tunnel --> Pietenpol-List message posted by: "Fred Weaver" Thanks Mike! Well said.... ----- Original Message ----- From: "bike.mike" Subject: Re: Pietenpol-List: Re: wind tunnel > --> Pietenpol-List message posted by: "bike.mike" > > Robert, et al: > > What is it that you expect to learn by performing a wind tunnel test? > If you want to enjoy the scientific lab work of building a model, setting up > and running a test, and analyzing results, the wind tunnel is a great > exercise that is fun in its own way. > If, however, you want to learn how the Piet wing performs, in its > full-scale, bug-smashed, real-life, application, there are thousands and > thousands of hours of actual flight, reported by the thousands of Piet > pilots of every possible skill level and scientific background who have > built and flown this little beauty in every conceivable configuration and > modification over the last 75 years. A wind tunnel test of any sort, even a > full-scale airplane in a large section tunnel at Langley in Virginia or at > Ames in California, is only going to give you an approximation of what is > learned in actual flight. > Enjoy your tunnel testing, but don't expect it to tell you anything usable > that hasn't already been learned. > > Mike Hardaway > (More hours in airplanes than on tunnels, but have enjoyed both for their > own sakes.) > > ----- Original Message ----- > From: Robert Haines > To: > Sent: Wednesday, February 18, 2004 7:00 AM > Subject: Pietenpol-List: Re: wind tunnel > > > > --> Pietenpol-List message posted by: "Robert Haines" > > > > > Max - starting on my airplane is currently in the queue, it's right behind > > restoring my 1866 house (I had it lifted off the foundation and replaced > the > > basement last winter) and my 1930 Model-A, and this last summer we had our > > second son (yea, my friends and family think I'm nuts). I've got my hands > > busy after hours. This wind tunnel thing is something I can sneak in on > my > > lunch hour. More to the point, it's actually part of what I would > consider > > my pre-building "homework" to an aircraft design that I'm sure I will > > modify. Until my after-work projects run their course, I'm doing OK > flying > > 152's periodically, at least I'm flying. > > > > Chris - So if I added little bumps and dips on the 24" scaled wing section > > the test would then be valid? Otherwise, the information is meaningless? > > Please reread my previous post regarding error in testing, all testing has > > error. At 1/10 scale (I'm considering a wing section with a 6" cord) the > > surface irregularities due to rib stitching is too small to matter. The > > deformation of the skin between the ribs is a consideration, but you would > > have to be a fortune teller to be able to guess what that deformation is > to > > any accuracy since the deformation changes under different speeds and > angle > > of attack. Not to mention there are those who consider adding an aluminum > > or plywood wrap around the front edge to midigate this and this would then > > be another set of models. > > > > Gesh, I'm just trying to do something that would be helpful to the group. > > > > > > Respectfully, > > > > Robert Haines > > Du Quoin, Illinois > > > > > > > > > > > > > > > > > > > >