This has a compounding effect, as the air that gets rubbed in turn slows down and rubs the air above (or below) it, cascading into a layer of “sticky air” known as the boundary layer. The reason this happens is because air moving close to the wing of an airplane actually sticks to the surface of the wing and rub against the air passing around the wing, inducing friction (which is called drag when talking about objects like airplanes). As air is a fluid as well, friction is the result of air rubbing against an airplane. Excessive kinetic energy in turbulent fluids results in seemingly random shifts in pressure and flow velocity, which appear as eddies, whorls, and vortices. The main reason to design against turbulent airflow is to reduce the drag on an airfoil or wing. If not designed against, turbulent flow can be much more present in a flying object than its counterpart. It is smooth, continuous, and predictable where turbulence is not. Laminar vs Turbulent FlowĪs discussed above, laminar is the opposite of turbulent. These wings were proof of the laminar flow theories first developed by German scientist Ludwig Prandtl years before real attempts were made at bringing these wings to flight.

Initially designed mathematically, a quarter scale model was tested in a wind tunnel by the California Institute of Technology.Īt first many manufacturers declined to continue developing wings with laminar flow in mind, as obtaining a totally smooth airfoil within exact tolerance proved to be too difficult for the days of the early 1930’s.Įventually, however, engineers were able to solve the smoothness conundrum by painting the entirety of the wings, and produced at least partially laminar flow wings. It is still up for debate upon historical review if the surface quality of wing material was sufficient enough to induce laminar flow in these early models. The P-51 Mustang was one of if not the first aircraft to intentionally be designed with laminar flow wings, by the National Advisory Committee for Aeronautics, the precursor to NASA. Minimizing this drag is important for safe and efficient airplane flight. It means bumpy, discontinuous flow that interrupts in point and ultimately creates drag through friction with the air. Turbulent air, on the other hand, does not just mean faster air. Laminar means smooth, continuous flow over the surface of a wing or airfoil, and it also means predictable. While that may seem obvious, it’s an important distinction. The distinction of what exactly laminar means, is that it is the opposite of turbulent, in simplest terms. In the case of an airplane, this flow occurs over streamlined parts of the airplane like a wing or fuselage. Flow is what happens as a fluid, either gas or liquid, moves in an uninterrupted fashion over an object. First we should define what exactly laminar flow is.

Laminar flow airfoil