L = (1/2) d v2 s CL
L = Lift, which must equal the airplane's weight in pounds
d = density of the air. This will change due to altitude.
v = velocity of an aircraft expressed in feet per second
s = the wing area of an aircraft in square feet
CL = Coefficient of lift , which is determined by the type of airfoil and angle of attack.
Dave, this formula applies to any force generated by an aerofiol of any sort... including yacht sails. Even when the kite is over our head we have dynamic pressure. The air is doing the moving... or is it the earth, us and the kite that is moving? Or both?
Also, I believe you mean centrifugal force which is mostly generated by the acting lift force. There would need to be greater weight at the kite end to generate a significant centrifugal force.
Angular acceleration = (final angular velocity - initial angular velocity) ÷ time
The lift forces will tend to lift the kite up, while the centrifugal forces will tend to pull the kite down.
In the lift formula we can/ or nature can change the following:
(d)DENSITY: the denser the air, the more molecules there are for the same parcel of air. On a hot day compared to a cold one the kite would need to move faster relative to physical distance travelled to generate the same amount of lift. But remember, denser air also means increased drag.
(v)VELOCITY: This is fairly self explanetry. The faster we move the kite through the air, the more lift we will generate. But once again the drag increases with velocity unproportionately to a point where we need too much thrust to go any faster. A couple of JATO rockets on the wingtips of our kites might help here.
(S)SURFACE AREA: This can sort of change this with kites but not much. If it were rigid it could not change unless it were like a swept wing aircraft. Swept wing aircraft use this to their advantage for greater surface area exposed for slow controlled flight and swept back (lower drag) for high speed flight. There are other factors t play here as well such as manouverablity. More on the swept wing jet at the end to paint a picture.
(CL)Co-efficient Of Lift: With the kite we can shorten or lenghten lines to increase or decrease the 'angle of attack' (AOA). Or just pull back on the bar!
Angle of attack is the angle between the kites chord line and the direct airflow.
***The swept wing jet is cruising along, straight and level, 2000 ft agl at Mach .9 with its wings swept back. It now wants to slow down to 210 knots whilst maintaining straight and level.
Now if we take our Lift formula we can see that if we decrease velocity we need to increase atleast one other thing to maintain a Lift force equally opposing the weight force to maintain straight and level. We could increase the aircrafts angle of attack (still maintaing straight and level), the lower the velocity, the higher the angle of attack required until we reach our critical angle where the airflow over the top of the wing starts to break away, the centre of pressure moves forward and the nose drops... we have stalled.
Or we could extend the wings changing the shape & surface area. This is changing Co-effient of Lift AND surface area.
In fact, our swept wing jet will extend its wings and increase its angle of attack as it decreases velocity to maintain straight and level flight.
Something interesting to note is that aspect ratio is a powerful indicator of the general performance of a wing. Wingtip vortices greatly deteriorate the performance of a wing, and by reducing the amount of wing tip area, making it skinny or pointed for instance, you reduce the amount of energy lost to this process, and increase the lift generated by the wing. This is why high performance gliders have very long, skinny wings; with no engine power, they must be as efficient as possible in every respect in order to stay aloft.
Most birds have wings with a wide aspect ratio, and with tapered or elliptical tips. This is particularly noticeable on soaring birds such as the Albatross and Eagles. In addition, the V-formation (echelon) often seen in flights of geese, ducks and other migratory birds can be considered to act as a single swept wing with a very high aspect ratio - the vortices shed by the lead bird are smoothly transferred to the next and so on. This confers a huge efficiency advantage to the flight as a whole - perhaps as much as a 100% improvement compared to a single bird in flight. Note that the usual common explanation of the V-formation - that following birds are "shielded" from air resistance by the bird in front - may be misleading. While birds do "take turns" at being the lead bird, it is probably to give those at the tips a rest - they are the ones that will experience the most drag when the vortices are finally shed.
Basically my wife will know the formulas' for what you are asking.
I will see what I can come up with before I ask her, but I've tried to cover the stuff I do know. Centrifugal force is an area I need to do a little more study on. I understand how they work in an aerobatic aircraft.
Also, I reckon Brownee may be able to explain more as well.
If so i can help you. I have something here that will see to it that that enormous pulsating mass of grey matter between your shoulders never bothers you again.he he [}:)]
