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Surface stresses and ripple formation due to low velocity air passing over a water surface

✍ Scribed by J.T. Davies; A. Qidwai; A. Hameed


Publisher
Elsevier Science
Year
1968
Tongue
English
Weight
600 KB
Volume
23
Category
Article
ISSN
0009-2509

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✦ Synopsis


batract -At low air speeds, from 24 cm set-a up to 100 cm set-1, the frktion coe6icient br of air passing over water decreases from 7.8 x lo-* to 4.9 x lo-'.

In our measurements we have used both Mm-covered water surfaces on which the stuface tension gradient exactly balances the wind stress, and also freely moving clean water surfaces. Though the results by both techniques are in agreement with each other, the former method is considerably more accuratethanthelatter.

Ripples become appreciable at air velocities of about 160 cm see-1 if the water surface is clean, but only above 320 cm sec~-~ if there is a captive monolayer on the surface. At tiual air velocitks. the amplitudes of the induced ripples when the monolayer is present are only about 9 per cent of those on a clean water surface.