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For example, the NACA 2412 airfoil has a maximum camber of 2% located 40% (0.4 chords) from the leading edge with a maximum thickness of 12% of the chord. The NACA 0015 airfoil is symmetrical, the 00 indicating that it has no camber. The 15 indicates that the airfoil has a 15% thickness to chord length ratio: it is 15% as thick as it is long.
The lift coefficient C L is defined by [2] [3] = =, where is the lift force, is the relevant surface area and is the fluid dynamic pressure, in turn linked to the fluid density, and to the flow speed.
NACA experience provided a model for World War II research, the postwar government laboratories, and NACA's successor, the National Aeronautics and Space Administration (NASA). NACA also participated in development of the first aircraft to fly to the "edge of space", North American's X-15. NACA airfoils are still used on modern aircraft.
For any given value of lift, the AoA varies with speed. Graphs of C L and C D vs. speed are referred to as drag curves. Speed is shown increasing from left to right. The lift/drag ratio is given by the slope from the origin to some point on the curve and so the maximum L/D ratio does not occur at the point of least drag coefficient, the ...
Clark Y is the name of a particular airfoil profile, widely used in general purpose aircraft designs, and much studied in aerodynamics over the years. The profile was designed in 1922 by Virginius E. Clark using thickness distribution of the German-developed Goettingen 398 airfoil. [1]
An angle of attack limiter or an "alpha limiter" is a flight computer that automatically prevents pilot input from causing the plane to rise over the stall angle. Some alpha limiters can be disabled by the pilot. Stall warning systems often involve inputs from a broad range of sensors and systems to include a dedicated angle of attack sensor.
For bar charts and pie charts with midangle this also defines if the text is inside or outside the chart. angle (pie charts only): text angle in degrees or midangle (default) for dynamic angles based on the mid-angle of the pie sector. innerRadius: For pie charts: defines the inner radius to create a doughnut chart.
The NACA design is believed to work because the combination of the gentle ramp angle and the curvature profile of the walls creates counter-rotating vortices which deflect the boundary layer away from the inlet and draws in the faster moving air, while avoiding the form drag and flow separation that can occur with protruding scoop designs.