6.4. SUSPENSION-DOMINATED MODELS
291
nature, as calm waves give way to storm conditions, could not be modeled
due to different model distortions required as wave period changes over the
course of the storm. Vellinga also remarked on the very small size of the
waves used in the tests conducted by Hallermeier in support of his modeling
relationship.
Fowler and Smith (1986) tested Hallermeier’s scaling relationship by
attempting to reproduce Saville’s (1957) prototype-scale accretive and erosive profiles developed from an initial plane sloping beach. Sand with d50
= 0.22 mm was used in the model, and the vertical scale was selected as
Nz - 30. Two different horizontal scales {Nz = 26, 34) were used in the
model to represent two different wave periods. Fowler and Smith reported
some cases of good correspondence between model and prototype, but only
for the accretive tests. Accretion was also observed for some of the cases
where erosion had occurred in the prototype.
The following example illustrates scale calculation using the suspensiondominated transport modeling relations discussed thus far.
Example 6.4. Comparison of Three Models
The National Foundation for the Advancement of Physical Modeling11 has
received funding to conduct a physical model study of equilibrium beach profile development occurring at Daytona Beach, Florida. Prior to model design, the dedicated
field crew, lead by none other than "George," spent an exhausting four days at Daytona Beach over Spring Break collecting vital data and communicating with local
beach visitors. They even remembered to bring home some sand samples.
Their careful analysis revealed that the native sediment was primarily quartz sand
having a relative density of ps/p = 2.65 and a median grain size diameter of about
movie set. The model sand had the same relative density as the prototype sand,
but its median diameter was d^o = 0.10 mm. The team decided to use the model
sand they had in stock, thus conserving a larger portion of their budget for necessary
semiannual PC software upgrades. This decision set the immersed sediment specific
weight scale, the immersed relative density scale, and the grain size diameter scale to
Nyi — Np> = 1
and
Nd = 2.6
respectively. These scale ratios were used to design the beach profile model using
the Noda Model, the Ito and Tsuchiya Model, and the Hallermeier Model. The
calculations are given below.
’A noble, but unfortunately fictitious, organization.
291
nature, as calm waves give way to storm conditions, could not be modeled
due to different model distortions required as wave period changes over the
course of the storm. Vellinga also remarked on the very small size of the
waves used in the tests conducted by Hallermeier in support of his modeling
relationship.
Fowler and Smith (1986) tested Hallermeier’s scaling relationship by
attempting to reproduce Saville’s (1957) prototype-scale accretive and erosive profiles developed from an initial plane sloping beach. Sand with d50
= 0.22 mm was used in the model, and the vertical scale was selected as
Nz - 30. Two different horizontal scales {Nz = 26, 34) were used in the
model to represent two different wave periods. Fowler and Smith reported
some cases of good correspondence between model and prototype, but only
for the accretive tests. Accretion was also observed for some of the cases
where erosion had occurred in the prototype.
The following example illustrates scale calculation using the suspensiondominated transport modeling relations discussed thus far.
Example 6.4. Comparison of Three Models
The National Foundation for the Advancement of Physical Modeling11 has
received funding to conduct a physical model study of equilibrium beach profile development occurring at Daytona Beach, Florida. Prior to model design, the dedicated
field crew, lead by none other than "George," spent an exhausting four days at Daytona Beach over Spring Break collecting vital data and communicating with local
beach visitors. They even remembered to bring home some sand samples.
Their careful analysis revealed that the native sediment was primarily quartz sand
having a relative density of ps/p = 2.65 and a median grain size diameter of about
movie set. The model sand had the same relative density as the prototype sand,
but its median diameter was d^o = 0.10 mm. The team decided to use the model
sand they had in stock, thus conserving a larger portion of their budget for necessary
semiannual PC software upgrades. This decision set the immersed sediment specific
weight scale, the immersed relative density scale, and the grain size diameter scale to
Nyi — Np> = 1
and
Nd = 2.6
respectively. These scale ratios were used to design the beach profile model using
the Noda Model, the Ito and Tsuchiya Model, and the Hallermeier Model. The
calculations are given below.
’A noble, but unfortunately fictitious, organization.