NACA cowling: Difference between revisions
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The test aircraft, a [[Curtis Hawk]] AT-5A biplane, featuring a Wright Whirlwind J-5 radial engine, reached an airspeed of 220km/h equipped with the NACA cowling compared to 190km/h without it. |
The test aircraft, a [[Curtis Hawk]] AT-5A biplane, featuring a Wright Whirlwind J-5 radial engine, reached an airspeed of 220km/h equipped with the NACA cowling compared to 190km/h without it. |
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The NACA cowling directs cool air to flow onto the center of the motor, where it is routed across the motor's hottest parts, i.e. the [[cylinders]] and even more importantly, the [[cylinder heads]]. Furthermore, turbulence after the air passes the free-standing cylinders is greatly reduced. The sum of all these effects reduces drag by 60%. |
The NACA cowling directs cool air to flow onto the center of the motor, where it is routed across the motor's hottest parts, i.e. the [[cylinders]] and even more importantly, the [[cylinder heads]]. Furthermore, turbulence after the air passes the free-standing cylinders is greatly reduced. The sum of all these effects reduces drag by as much as 60%. |
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The test conclusions resulted in almost every aircraft being equipped with this cowling, starting in [[1932]]. |
The test conclusions resulted in almost every aircraft being equipped with this cowling, starting in [[1932]]. |
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Revision as of 16:25, 20 October 2006
The NACA cowling is a type of aerodynamic fairing used to streamline radial engines for use on airplanes. Developed by the National Advisory Committee for Aeronautics in 1927, it was a major advancement in drag reduction, and paid for its development and installation costs many times over due to the gains in fuel economy that it enabled.
The test aircraft, a Curtis Hawk AT-5A biplane, featuring a Wright Whirlwind J-5 radial engine, reached an airspeed of 220km/h equipped with the NACA cowling compared to 190km/h without it.
The NACA cowling directs cool air to flow onto the center of the motor, where it is routed across the motor's hottest parts, i.e. the cylinders and even more importantly, the cylinder heads. Furthermore, turbulence after the air passes the free-standing cylinders is greatly reduced. The sum of all these effects reduces drag by as much as 60%.
The test conclusions resulted in almost every aircraft being equipped with this cowling, starting in 1932.
See also
External links
- NACA Low-Drag Engine Cowling Essay - details on development of the cowling.
- NACA Technical Note 301 - Fred Weick's original (all-text) report of November 1928. [PDF, 1.4 MB]