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Aerodynamics   Subsonic Wings Learn Aerospace Engineering, WHAT MAKES A WING WORK? Let's use a wing to help get a better understanding of lift at subsonic speeds. With a typical subsonic wing, the upper surface is more curved than the lower surface. The curved upper surface constricts the flow of air more than the flatter lower surface, causing the air above the wing to speed up more than the air below. The faster the air speeds up, the lower its pressure becomes. So the faster moving air above has less pressure than the slower moving air below. (Remember, this relationship between pressure and speed is called Bernoulli’s principle.) The higher air pressure below pushes the wing up—lift.  Any further increase in the speed of the air will increase the difference in pressure and increase the lifting force on the wing.    

Aerodynamics Air in Motion Learn Aerospace Engineering, FLIGHT BEGINS WITH AIR IN MOTION As an airplane moves through the air, its wings cause changes in the speed and pressure of the air moving past them. These changes result in the upward force called lift. To understand lift, you first have to understand how air (a gas) behaves under certain conditions. BERNOULLI PRINCIPLE Let's start with the Bernoulli principle. The Bernoulli principle states that an increase in the speed of a fluid occurs simultaneously with a decrease in the pressure exerted by the fluid. WHY DOES THE AIR  SPEED UP? When moving air encounters an obstacle—a person, a tree, a wing—its path narrows as it flows around the object. Even so, the amount of air moving past any point at any given moment within the airflow is the same. For this to happen, the air must either compress or speed up where its flow narrows. While air can be compressed more easily than water, freely flowing air acts much like water—at least ...

Aerodynamics Aerodynamics of Automobiles Learn Aerospace Engineering, Aerodynamics of Automobiles Automobiles started using aerodynamic body shapes in the early part of their history. As engines became more powerful and cars became faster, automobile engineers realized that wind resistance significantly hindered their speed. The first cars to adopt improved aerodynamics, or streamlining, were racing cars and those attempting to break the  land speed record . "Dreamers, engineers, racers and entrepreneurs were lured by the potential for the profound gains aerodynamics offered," wrote Paul Niedermeyer, author of " Automotive History: An Illustrated History Of Automotive Aerodynamics ," on the website Curbside Classic. "The efforts to do so yielded some of the more remarkable cars ever made, even if they challenged the aesthetic assumptions of their times." Regarding the  aerodynamics of a racing car , Dr. Joe David, professor of mechanical and aerospace engi...

Aerodynamics What Is Aerodynamics? Learn Aerospace Engineering, What Is Aerodynamics? Aerodynamics is the study of how gases interact with moving bodies. Because the gas that we encounter most is air, aerodynamics is primarily concerned with the forces of drag and lift, which are caused by air passing over and around solid bodies. Engineers apply the principles of aerodynamics to the designs of many different things, including buildings, bridges and even soccer balls; however, of primary concern is the aerodynamics of aircraft and automobiles. Aerodynamics comes into play in the study of flight and the science of building and operating an aircraft, which is called aeronautics. Aeronautical engineers use the fundamentals of aerodynamics to design aircraft that fly through the Earth's atmosphere. Aerodynamic  drag The most significant aerodynamic force that applies to nearly everything that moves through the air is drag. Drag is the force that opposes an aircraft's motion through...

  Aerodynamics Introduction to Aerodynamics Learn Aerospace Engineering, Introduction to Aerodynamics Flying still kind of magic every time. The math describing Fluid Dynamics was extensively studied and eventually written down in a complete set of Partial Differential Equations known as the  Navier -Stokes .  Those equations are so involved that mathematicians had been working on them for years trying to find out some assumption that could lead to a simplified sub-set, detailed enough to study basic aerodynamics in closed form. One of the most abused assumption was to   discard the friction from the equation (potential flow only) .   That looked to be a reasonable assumption (as friction in the air is low compared to other factors),  however it leads to the impossible result that no drag exists   and thus nothing can fly! ( known  as the  D'Alambert  paradox). It was only in early 1900 that  two brothers  figured it out, ...