Original Posted By: rhartwig11(at)juno.com
Subject: Pietenpol-List: Wind Tunnel
Pietenpol-List: Wind Tunnel
RE: Pietenpol-List: Wind Tunnel
Original Posted By: "Ken Chambers"
Re: Pietenpol-List: Wind Tunnel
Original Posted By:
Dick,I appreciate what your ironic letter was trying to accomplish; I, too, thinkmore knowledge is better. I have spent a good portion of my life infurthering the quest for aerodynamic knowledge.However, the wind tunnel testing that has been bandied about on the listwon't produce any usable knowledge that hasn't already been learned,sometimes the hard way, in flight.For example, it has long been known that a more rounded leading edge on the"FC-10" makes for more gentle and predictable stall characteristics. A windtunnel test, if it is properly scaled, set up and analyzed, will show thesame thing. If it is not properly done, though, it may show somethingcompletely different. If those results lead someone to, for instance,sharpen the leading edge, the result could be disastrous. (At smallReynolds Numbers, a sharp leading edge works very well.)There are many other examples where an improperly run wind tunnel test canproduce results that don't help, and can even hurt, the acquisition ofknowledge.You mention the Wright brothers' wind tunnel testing. They did learn somevery useful things in their little tunnel. They also learned, or thoughtthey did, that a canard configuration that was unstable in pitch and rollwas best for the 1903 flyer. They didn't "unlearn" that until the 1908 and1910 airplanes.Mike Hardaway----- Original Message -----
Dick,I appreciate what your ironic letter was trying to accomplish; I, too, thinkmore knowledge is better. I have spent a good portion of my life infurthering the quest for aerodynamic knowledge.However, the wind tunnel testing that has been bandied about on the listwon't produce any usable knowledge that hasn't already been learned,sometimes the hard way, in flight.For example, it has long been known that a more rounded leading edge on the"FC-10" makes for more gentle and predictable stall characteristics. A windtunnel test, if it is properly scaled, set up and analyzed, will show thesame thing. If it is not properly done, though, it may show somethingcompletely different. If those results lead someone to, for instance,sharpen the leading edge, the result could be disastrous. (At smallReynolds Numbers, a sharp leading edge works very well.)There are many other examples where an improperly run wind tunnel test canproduce results that don't help, and can even hurt, the acquisition ofknowledge.You mention the Wright brothers' wind tunnel testing. They did learn somevery useful things in their little tunnel. They also learned, or thoughtthey did, that a canard configuration that was unstable in pitch and rollwas best for the 1903 flyer. They didn't "unlearn" that until the 1908 and1910 airplanes.Mike Hardaway----- Original Message -----
Re: Pietenpol-List: Wind Tunnel
Original Posted By: "Ted Brousseau"
Subject: Re: Pietenpol-List: Wind TunnelTo Dick and Ken and Others:I disagree! I would like to know as much about the plane I am going to fly for my sake and the sake of the passengers I will be responsible for when I do. We ALL know that the plane BHP designed is GOOD, SOUND and RELIABLE. Who said anything about changing the BHP design! I believe that Robert's whole concept with the FC10 airfoil and wind tunnel plan is for general all purpose,wouldn't be neat to know, you could win beers at parties with this stuff, DATA. The design doesn't have to change and I don't think anyone has stated oris encouraging any changes. I am planning on building mine as close as possible to the plans with most of the notable improvements (Cont. 85, tail wheel,...). If anything does come of the tunnel tests and data is placed on the list, if you don't want to save it, store it or use it, please press DELETE. Knowledgeis power. Know all there is to know about what your sitting in.Greg MenocheDelaware________________________________________________________________________________
Subject: Re: Pietenpol-List: Wind TunnelTo Dick and Ken and Others:I disagree! I would like to know as much about the plane I am going to fly for my sake and the sake of the passengers I will be responsible for when I do. We ALL know that the plane BHP designed is GOOD, SOUND and RELIABLE. Who said anything about changing the BHP design! I believe that Robert's whole concept with the FC10 airfoil and wind tunnel plan is for general all purpose,wouldn't be neat to know, you could win beers at parties with this stuff, DATA. The design doesn't have to change and I don't think anyone has stated oris encouraging any changes. I am planning on building mine as close as possible to the plans with most of the notable improvements (Cont. 85, tail wheel,...). If anything does come of the tunnel tests and data is placed on the list, if you don't want to save it, store it or use it, please press DELETE. Knowledgeis power. Know all there is to know about what your sitting in.Greg MenocheDelaware________________________________________________________________________________
Re: Pietenpol-List: Wind Tunnel
Original Posted By: jimboyer(at)direcway.com
Mike Hardaway,You go out and fly around and when you land, please graph out the polar forthe FC-10. That will spare us all a lot of work trying to come up with itthe best we can the more traditional way.Oh, also, I need the chordwise lift distribution at AOA's from -4 to 19degrees to size spars.I will eagerly await your results.chris bobka________________________________________________________________________________Date: Thu, 19 Feb 2004 22:18:25 -0800
Mike Hardaway,You go out and fly around and when you land, please graph out the polar forthe FC-10. That will spare us all a lot of work trying to come up with itthe best we can the more traditional way.Oh, also, I need the chordwise lift distribution at AOA's from -4 to 19degrees to size spars.I will eagerly await your results.chris bobka________________________________________________________________________________Date: Thu, 19 Feb 2004 22:18:25 -0800
Re: Pietenpol-List: Wind Tunnel
Original Posted By:----- Original Message ----- Christian Bobka
Coming right up, Chris, as soon as I install the strain gauges on the flyingwires and getting the multi-channel data link to work. Oh, and finish theairplane.
Coming right up, Chris, as soon as I install the strain gauges on the flyingwires and getting the multi-channel data link to work. Oh, and finish theairplane.