![]() |
If this is your first visit, be sure to check out the FAQ by clicking the link above. You may have to register before you can post: click the register link above to proceed. To start viewing messages, select the forum that you want to visit from the selection below. |
|
|
Thread Tools | Display Modes |
#11
|
|||
|
|||
![]()
At 23:51 05 January 2011, ProfChrisReed wrote:
I'm still not convinced by those who propose that the wings of the glider generate no extra lift (or even generate less lift) when climbing on tow. We know that on a winch launch the glider climbs because the wings generate more lift than in level/descending flight. This must be true because there is nothing pulling it up. However, we are told that on aerotow the wings generate the same (or less) lift as in level/descending flight and the tug just pulls the glider up the slope. Does this mean that the tug climbs in the same way, i.e. wings generate only enough lift to carry the weight of the tug, and the prop drags the tug up the slope? This doesn't match what I've read about how aircraft work. L=W only in level flight. I think the tug's wings generate more lift than its weight, and thus it climbs. If this is true, the same must be true for the glider behind it. Bring on an aerodynamicist to show me I'm wrong. Chris Yes, it does mean the tug climbs in the same way - the prop is dragging it uphill. In steady climb or descent the lift is actually slightly less than weight, with the remaning very small component of the weight balanced by the drag (in a glide) or the thrust (in a climb). This can be demonstrated very easily with a vector diagram of the forces acting on an aircraft, and you'll find this picture in every textbook on aircraft performance or flight dynamics. If you'd like to talk to an aerodynamicist, there are several contributing to this thread - but more locally Dr Graham Dorrington in the engineering department at Queen Mary has worked on an electric-powered sailplane http://www.flightglobal.com/articles...ane-flies.html and should be able to convince you. Doug (aerodynamicst & flight dynamicist at City University) |
Thread Tools | |
Display Modes | |
|
|
![]() |
||||
Thread | Thread Starter | Forum | Replies | Last Post |
another poor man's car engine conversion | jan olieslagers[_2_] | Home Built | 19 | February 22nd 09 03:49 PM |
Poor readability | Kees Mies | Owning | 2 | August 14th 04 04:22 AM |
Poor Guy | Bob Chilcoat | Owning | 6 | July 17th 04 06:45 PM |
I'm grateful for poor people who are willing to murder & die | Krztalizer | Military Aviation | 0 | April 20th 04 11:11 PM |
Concorde in FS2002: No lateral views | A. Bomanns | Simulators | 3 | July 19th 03 11:33 AM |