6.4. SUSPENSION-DOMINATED MODELS
287
geometric distortion of Q = 2. (Use of the revised Eqns. 6.83 and 6.84
from Noda (1972) would have produced model scales of Nz = 173 and Nx
= 467, which would have been a significantly smaller model.) Chatham
reported that the scale model produced reasonable correspondence to profile shapes documented for large-scale wave tank experiments of a similar
perched beach.
Collins and Chestnutt (1975) conducted four laboratory tests of Noda’s
scaling guidance using slightly distorted models (Q = 1.2 to 1.5). They did
not have great success in correctly predicting prototype-scale equilibrium
profiles, but they did predict foreshore slope correctly in three of the four
tests. The shape of the offshore profile and inshore zones were not correctly
reproduced, and the movement of the shoreline was not correctly predicted.
Collins and Chestnutt recommended against general use of Noda’s (1972)
scaling criteria.
Dean (1985) reviewed Noda’s work and Collins and Chestnutt’s (1975)
results, and he commented that further efforts were needed to better define appropriate scaling for movable-bed models of surf zones (turbulencedominated sediment transport). Dean found particularly “bothersome” the
commitment to distorted models of the surf zone; and he offered his own
recommendations, which are discussed in detail in the section entitled Scale
Criteria Dependent on Fall Speed.
Hallermeier (1985) reviewed Noda’s scaling guidance, along with several
other sets of movable-bed modeling criteria. He objected to Noda’s use of
relatively mild, accretive conditions for establishing the modeling criteria,
and stated that this biased the results toward low energy waves and coarse
sediments. Hallermeier also felt that it was incorrect to limit the empirical
basis of the model to replication of just the beach foreshore slope.
Fowler and Smith (1986) examined the capability of Noda’s (1972) scaling relationships to reproduce both an accretive and an erosive profile from
an initial plane sloping beach. Saville’s (1957) large-scale wave tank tests
were taken as the prototype condition. Fowler and Smith conducted tests
using crushed coal (ps/p = 1.40, (/50 = 1.4 mm) and glass beads (ps/p -
2.42, d50 = 0.07 mm) as the model sediment. They reported all tests of
Noda’s (1972) model scaling to be unsuccessful, with all tests producing
erosion profiles even when accretion occurred in the prototype.
Ito and Tsuchiya’s Modeling Criteria
Ito and Tsuchiya (1984) conducted experiments in two wave flumes of different size and used the results to develop movable-bed scale criteria for
modeling equilibrium beach profiles. The equilibrium profiles that developed in the larger flume were considered to be the prototype, and tests in
287
geometric distortion of Q = 2. (Use of the revised Eqns. 6.83 and 6.84
from Noda (1972) would have produced model scales of Nz = 173 and Nx
= 467, which would have been a significantly smaller model.) Chatham
reported that the scale model produced reasonable correspondence to profile shapes documented for large-scale wave tank experiments of a similar
perched beach.
Collins and Chestnutt (1975) conducted four laboratory tests of Noda’s
scaling guidance using slightly distorted models (Q = 1.2 to 1.5). They did
not have great success in correctly predicting prototype-scale equilibrium
profiles, but they did predict foreshore slope correctly in three of the four
tests. The shape of the offshore profile and inshore zones were not correctly
reproduced, and the movement of the shoreline was not correctly predicted.
Collins and Chestnutt recommended against general use of Noda’s (1972)
scaling criteria.
Dean (1985) reviewed Noda’s work and Collins and Chestnutt’s (1975)
results, and he commented that further efforts were needed to better define appropriate scaling for movable-bed models of surf zones (turbulencedominated sediment transport). Dean found particularly “bothersome” the
commitment to distorted models of the surf zone; and he offered his own
recommendations, which are discussed in detail in the section entitled Scale
Criteria Dependent on Fall Speed.
Hallermeier (1985) reviewed Noda’s scaling guidance, along with several
other sets of movable-bed modeling criteria. He objected to Noda’s use of
relatively mild, accretive conditions for establishing the modeling criteria,
and stated that this biased the results toward low energy waves and coarse
sediments. Hallermeier also felt that it was incorrect to limit the empirical
basis of the model to replication of just the beach foreshore slope.
Fowler and Smith (1986) examined the capability of Noda’s (1972) scaling relationships to reproduce both an accretive and an erosive profile from
an initial plane sloping beach. Saville’s (1957) large-scale wave tank tests
were taken as the prototype condition. Fowler and Smith conducted tests
using crushed coal (ps/p = 1.40, (/50 = 1.4 mm) and glass beads (ps/p -
2.42, d50 = 0.07 mm) as the model sediment. They reported all tests of
Noda’s (1972) model scaling to be unsuccessful, with all tests producing
erosion profiles even when accretion occurred in the prototype.
Ito and Tsuchiya’s Modeling Criteria
Ito and Tsuchiya (1984) conducted experiments in two wave flumes of different size and used the results to develop movable-bed scale criteria for
modeling equilibrium beach profiles. The equilibrium profiles that developed in the larger flume were considered to be the prototype, and tests in