TY - JOUR
T1 - The Contraction Coefficient of a Free-Surface Flow Under Gravity Entering a Region Beneath a Semi-Infinite Plane
AU - L. H. Wiryanto & H. B. Supriyanto
JO - East Asian Journal on Applied Mathematics
VL - 4
SP - 342
EP - 352
PY - 2018
DA - 2018/02
SN - 2
DO - http://doi.org/10.4208/eajam.240912.141112a
UR - https://global-sci.org/intro/article_detail/eajam/10881.html
KW - Borda's mouthpiece, free-surface flow, boundary integral equation, contraction coefficient.
AB - <p style="text-align: justify;">Borda&#39;s mouthpiece consists of a long straight tube projecting into a large
vessel, where fluid enters the tube in a free surface flow that tends to become uniform
far downstream in the tube. A two-dimensional approximation to this flow under gravity
in the upper part of the tube leads to an evaluation of the contraction coefficient, the
ratio of the constant depth of the uniform flow to the width of the tube. The analysis
also applies to flow under gravity past a sluice gate, if the semi-infinite wall above the
channel is rotated to the vertical. The contraction coefficient depends upon the Froude
number F, and is generally less than the zero gravity value of 1/2 that is approached as $F → ∞$.</p>