annular effect

annular effect

[′an·yə·lər i′fekt]
(fluid mechanics)
A phenomenon observed in the flow of fluid in a tube when its motion is alternating rapidly, as in the propagation of sound waves, in which the mean velocity rises progressing from the center of the tube toward the walls and then falls within a thin laminar boundary layer to zero at the wall itself.
References in periodicals archive ?
It increases the annular effect, while still showing the central star, and allowing high powers to be used.