On Jan 1, 2015 1:36 PM, "Mac McConnell-Wood via KRnet" <krnet at list.krnet.org> wrote: > > Avro's should have read that before designing the Vulcan air > brakes....fancy putting those solid slabs upwind of the flying controls..! > > See the pairs of yellow lines indicating position. >
That main control surfaces on a Delta wing is way out of the turbulence of the air brake... The vert is humongous! > Regards and a HNY to all our readers > Mac > > On Wed, Dec 31, 2014 at 1:19 PM, Mike via KRnet <krnet at list.krnet.org> > wrote: > > > A little science from English researchers in 1957 > > http://naca.central.cranfield.ac.uk/reports/arc/cp/0323.pdf but I'm sure > > there must be more recent published findings from elsewhere. > > > > This suggests that a solid airbrake produces a bubble of reduced airflow > > behind the brake with airflow velocity fluctuations occurring around the > > edge of the brake which may cause vibrations to the structure. Perforations > > in the airbrake reduce this effect and were found to be more effective > > towards the centre of the plate than around the periphery. > > > > From the Pprune forum, this explanation was offered: "Perforation reduces > > buffeting downrange of the speed brake, and reduces its interference with > > flying surfaces or the fuselage or wing or horizontal stab. Remember, the > > speed brake is there to create drag, but not undesirable flight > > characteristics. A perforated brake doesn't create nearly the airflow > > disruption, pitch change, or load on the surrounding and supporting > > structure that a solid brake might create. The number and placement of > > holes > > are important considerations, and part of the design. Holes permit a > > lighter > > structure that takes less of an airload, reducing not only the weight of > > the > > brake assembly but the force required to actuate it and the structure > > around > > it that must support the load. Remember that much of the time, that speed > > brake isn't anything but dead weight." > > > > Mike Mold > > Devon, UK. > > > > -----Original Message----- > > From: KRnet [mailto:krnet-bounces at list.krnet.org] On Behalf Of Mac > > McConnell-Wood via KRnet > > Sent: 31 December 2014 10:35 > > To: Herbert F?rle; KRnet > > Subject: Re: KR> Bellyboard > > > > The RAF Vulcan bomber had solid airbrakes-no holes (which enabled this 90 > > ton delta to descend vertically-..been there..) > > Mac > > > > On Wed, Dec 31, 2014 at 9:51 AM, Herbert F?rle <krnet at list.krnet.org> > > wrote: > > > > > > > > ....any Test,however it is performed,gives a lot of informations! The > > > aerodynamic principles are always the same ,also in the case of the hot" > > > bellyboard -drag" discusion.For me it's important the location of the > > board > > > and I think the place underneath the rearspar is very well chosen ( far > > > enough behind the CG ,to give the Kr a small amount of direction > > stability > > > like a dragchute and the waketurbulences does'nt hit the HS !) I 'm > > > convinced,a board without holes are more effectiv ( one big > > waketurbulence > > > produce more drag compared to many small ones). > > > I'm also think,a big advantage of the bellyboard is the fact ,that you > > can > > > lower the nose of the Kr on final for better sight( wether you have to > > push > > > or pull the stik )! > > > Herbert > > > German Kr builder . > > > > > > > > > Von meinem iPad gesendet > > > _______________________________________________ > > > Search the KRnet Archives at http://tugantek.com/archmailv2-kr/search. > > > To UNsubscribe from KRnet, send a message to KRnet-leave at list.krnet.org > > > please see other KRnet info at http://www.krnet.org/info.html > > > see http://list.krnet.org/mailman/listinfo/krnet_list.krnet.org to > > change > > > options > > > > > _______________________________________________ > > Search the KRnet Archives at http://tugantek.com/archmailv2-kr/search. > > To UNsubscribe from KRnet, send a message to KRnet-leave at list.krnet.org > > please see other KRnet info at http://www.krnet.org/info.html > > see http://list.krnet.org/mailman/listinfo/krnet_list.krnet.org to change > > options > > > > > > _______________________________________________ > > Search the KRnet Archives at http://tugantek.com/archmailv2-kr/search. > > To UNsubscribe from KRnet, send a message to KRnet-leave at list.krnet.org > > please see other KRnet info at http://www.krnet.org/info.html > > see http://list.krnet.org/mailman/listinfo/krnet_list.krnet.org to change > > options > > > > _______________________________________________ > Search the KRnet Archives at http://tugantek.com/archmailv2-kr/search. > To UNsubscribe from KRnet, send a message to KRnet-leave at list.krnet.org > please see other KRnet info at http://www.krnet.org/info.html > see http://list.krnet.org/mailman/listinfo/krnet_list.krnet.org to change options >
