TITLE:
Utilizing Dimensional Analysis with Observed Data to Determine the Significance of Hydrodynamic Solutions in Coastal Hydrology
AUTHORS:
Eric D. Swain, Jeremy D. Decker, Joseph D. Hughes
KEYWORDS:
Hydrodynamic, Dimensional Analysis, Coastal, Numerical Modeling
JOURNAL NAME:
Computational Water, Energy, and Environmental Engineering,
Vol.3 No.2,
April
25,
2014
ABSTRACT: In this paper, the
authors present an analysis of the magnitude of the temporal and spatial acceleration (inertial) terms in the surface-water flow equations and determine the
conditions under which these inertial terms have sufficient magnitude to be
required in the computations. Data from two South Florida field sites are
examined and the relative magnitudes of temporal acceleration, spatial
acceleration, and the gravity and friction terms are compared. Parameters are
derived by using dimensionless numbers and applied to quantify the
significance of the hydrodynamic effects. The time series of the ratio of the
inertial and gravity terms from field sites are presented and compared with
both a simplified indicator parameter and a more complex parameter called the
Hydrodynamic Significance Number (HSN).
Two test-case models were developed by using the SWIFT2D hydrodynamic simulator
to examine flow behavior with and without the inertial terms and compute the HSN. The first model represented one of
the previously-mentioned field sites during gate operations of a
structure-managed coastal canal. The second model was a synthetic test case
illustrating the drainage of water down a sloped surface from an initial stage
while under constant flow. The analyses indicate that the times of substantial
hydrodynamic effects are sporadic but significant. The simplified indicator
parameter correlates much better with the hydrodynamic effect magnitude for a
constant width channel such as Miami Canal than at the non-uniform North River.
Higher HSN values indicate flow
situations where the inertial terms are large and need to be taken into
account.