Aerodynamics

Ingles Tecnico
Aerodynamics


Aerodynamics
The word aerodynamics comes from two Greek words “Aerios” concerning the air and dynamics which mean “Force”. Knowing this, we can deduce aerodynamics study the force what air make over the things, saying in other way, aerodynamics is the way that air moves around things and their rules describe how the airplanes are able to fly or how the cars movethrough air, how the buildings react to strong winds, and also how people get energy with the wind.
Since the Wright brother we have improved the air planes thanks to the aerodynamics, now we have complex and efficient high-speed airplanes, the biggest airport on the history, the sonic barrier is not a barrier any more, and the speed records are farther that someone would have thought.Nevertheless the real development on the aerodynamics started in the half-twenty century actually nowadays man whose study aerodynamics have to be example of co-cooperation between men and mathematics, but we see on the past the man whose study aerodynamics were a artistic with inspiration on birds as Leonardo Da Vinci. Actually nowadays we use the seems inspiration, the experts said that only are twoways to fly, the first one is like a bird do and the second method is like the helicopter do in this days whose propulsion and sustentation are produced by the motion of the prop.
Actually the studies of aerodynamics are too ass old ass the science of mechanics, for example Aristotle 384-322 B.C mentions the problem of solid bodies moving in air.
Galileo Galilee 1564-1642. He said that themovement of a pendulum was slowly amortized by air resistance and actually tried to determine the dependence of air resistance on velocity.
Giovanni Battista Venturi 1746-18822 was an iltalian physicst he mentions the the Vinturi effect. This effect is the venture effect describe the reduction on the fuid pressure when a fluid flows through a constricted section of pipe
Sir Isaac Newton observe thatthe force between a solid body and a fluid are the same if the solid body move through the fluid with constant velocity and the fluid move against the solid body.
Experimental evidence has show that three of Newton’s statements were correct
1. The proportionality to the density
2. The proportionality to the square of the liner dimension
3. The proportionality to the square ofvelocity.

Of course the last of these is restricted to small or moderate speeds because knows even in the Newton’s time, it does not apply to velocities superior to the velocity of sound. These three laws contributed to the pessimistic forecast one could find in the scientific literature on the possibilities of powered flight.
In1878 lord Rayleigh, studied the flow around a circular cylinder and hefound that, if the cylinder is exposed to a parallel uniform flow or moves uniformly through a fluid at rest, but the superposition of a circulatory flow upon a parallel uniform flow produces a force perpendicular to the direction of the original flow, or perpendicular to the direction of the original flow, or perpendicular to the direction on the motion of the cylinder. This result was used toexplain the so-called Magnus effect.

The physical laws that govern fluid flow are deceptively simple. Paramount among them is Newton’s second law of motion which states that
Mass x acceleration = applied force
In fluid mechanics we prefer to use the equivalent form od
Rate of change od momentum = applied force
Apart from the principles of conservation of mass of energy, the reaming physicallaws required relate solely to determining the force involved. For a wide range of applications in aerodynamics the only force involved are the body forces due to the action of gravity.
Air flow
Consider an airplane in steady flight. To an observe on the ground the airplane is flying into the air substantially at rest, assuming no wing and any movement of air is caused directly by the motion of...