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The flow profile of laminar flow in a tube can be calculated by dividing the flow into thin cylindrical elements and applying the viscous force to them. [ 5 ] Another example is the flow of air over an aircraft wing .
A laminar flow wing has a maximum thickness in the middle camber line. Analyzing the Navier–Stokes equations in the linear regime shows that a negative pressure gradient along the flow has the same effect as reducing the speed.
Maintaining laminar flow by controlling the pressure distribution on an airfoil is called Natural laminar flow (NLF) [7] and has been achieved by sailplane designers with great success. [9] On swept wings a favorable pressure gradient becomes destabilizing due to cross flow and suction is necessary to control cross flow. [10]
An example of this type of boundary layer flow is near-wall air flow over a wing in flight. The unbounded boundary layer concept is depicted for steady laminar flow along a flat plate in Figure 2. The lower dashed curve represents the location of the maximum velocity u max ( x ) and the upper dashed curve represents the location where u ( x , y ...
Laminar boundary layer flow. The laminar boundary is a very smooth flow, while the turbulent boundary layer contains swirls or "eddies." The laminar flow creates less skin friction drag than the turbulent flow, but is less stable. Boundary layer flow over a wing surface begins as a smooth laminar flow.
"a=" followed by a decimal number describing the fraction of chord over which laminar flow is maintained. a=1 is the default if no value is given. For example, the NACA 65 4 -415, has the minimum pressure placed at 50% of the chord, has a maximum thickness of 15% of the chord, design lift coefficient of 0.4 and maintains laminar flow for lift ...
A reasonable assessment of whether the boundary layer will be laminar or turbulent can be made by calculating the Reynolds number of the local flow conditions. Separation occurs in flow that is slowing down, with pressure increasing, after passing the thickest part of a streamline body or passing through a widening passage, for example.
The Davis wing is a World War II-era aircraft wing design that was used by Consolidated Aircraft on the Consolidated B-24 Liberator, as well as other models. The airfoil had a lower drag coefficient than most contemporary designs, which allowed higher speeds, and created significant lift at relatively low angles of attack.