No CrossRef data available.
We use cookies to distinguish you from other users and to provide you with a better experience on our websites. Close this message to accept cookies or find out how to manage your cookie settings.
We use cookies to distinguish you from other users and to provide you with a better experience on our websites. Close this message to accept cookies or find out how to manage your cookie settings.
Published online by Cambridge University Press: 14 September 2016
In “Die Naturwissenschaften,” 6th February, 1925, p. 93, there appears an article by Prandtl entitled “ Magnuseffekt und Windkraftschiff,” giving the following explanation of the phenomena under consideration.
In a stream of viscous fluid a non-rotating cylinder builds up an accumulation of retarded fluid with considerable vorticity (Fig. 5). This fluid reaches the neighbourhood of the near dead water point with a loss of kinetic energy and velocity by dissipation. At the somewhat indeterminate boundary of the boundary layer it is in contact with fluid which has lost its kinetic energy and velocity in acquiring an increase of pressure approaching the dead water pressure. The retarded fluid is pushed away from the dead water point by the higher pressure fluid (Figs. 6, 7), and ultimately it breaks up into cylindrical masses which are detached and carried away by the stream (Fig. 8).
Erratum p. 104, line 11, for “non-rotating cylinder,” read “cylinder without end caps.”
* It is seen that there is complete incompatibility between this explanation, and that suggested by the writer in the last article. The grounds of disagreement are wider than a particular result. The writer's explanation was not a guess hazarded at random, but was carefully constructed on the basis of views first stated by Kelvin, and developed by Riabouschinsky. There are, moreover, several difficulties raised by Prandtl's theory, some of which seem fundamental. The writer does not propose to go into detailed comment here, but rather to complete his views on the physical processes of fluid motion for statement later as a whole. The whole matter must remain somewhat speculative until many crucial experiments have been carried out.