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Impingement of Droplets in 60 Deg Elbows with Potential FlowTrajectories were determined for water droplets or other aerosol particles in air flowing through 600 elbows especially designed for two-dimensional potential motion. The elbows were established by selecting as walls of each elbow two streamlines of a flow field produced by a complex potential function that establishes a two-dimensional flow around. a 600 bend. An unlimited number of elbows with slightly different shapes can be established by selecting different pairs of streamlines as walls. Some of these have a pocket on the outside wall. The elbows produced by the complex potential function are suitable for use in aircraft air-inlet ducts and have the following characteristics: (1) The resultant velocity at any point inside the elbow is always greater than zero but never exceeds the velocity at the entrance. (2) The air flow field at the entrance and exit is almost uniform and rectilinear. (3) The elbows are symmetrical with respect to the bisector of the angle of bend. These elbows should have lower pressure losses than bends of constant cross-sectional area. The droplet impingement data derived from the trajectories are presented along with equations so that collection efficiency, area, rate, and distribution of droplet impingement can be determined for any elbow defined by any pair of streamlines within a portion of the flow field established by the complex potential function. Coordinates for some typical streamlines of the flow field and velocity components for several points along these streamlines are presented in tabular form. A comparison of the 600 elbow with previous calculations for a comparable 90 elbow indicated that the impingement characteristics of the two elbows were very similar.
Document ID
19810068701
Acquisition Source
Legacy CDMS
Document Type
Other - NACA Technical Note
Authors
Hacker, Paul T.
(National Advisory Committee for Aeronautics. Lewis Flight Propulsion Lab. Cleveland, OH, United States)
Saper, Paul G.
(National Advisory Committee for Aeronautics. Lewis Flight Propulsion Lab. Cleveland, OH, United States)
Kadow, Charles F.
(National Advisory Committee for Aeronautics. Lewis Flight Propulsion Lab. Cleveland, OH, United States)
Date Acquired
August 11, 2013
Publication Date
October 1, 1956
Subject Category
Fluid Mechanics And Heat Transfer
Report/Patent Number
NACA-TN-3770
Report Number: NACA-TN-3770
Accession Number
81N73123
Distribution Limits
Public
Copyright
Work of the US Gov. Public Use Permitted.
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