Geoscience Reference
In-Depth Information
Table 3.1
Values of
M
,
N
, and
n
Author
M
N
n
Rubey (1933)
24
2.1
1
Zhang (1961)
34
1.2
1
Zanke (1977)
24
1.1
1
Raudkivi (1990)
32
1.2
1
Julien (1995)
24
1.5
1
Cheng (1997)
32
1
1.5
Eqs. (3.9), (3.12), (3.13), and (3.16) are valid for naturally worn sediment particles,
the Corey shape factors of which usually are about 0.7. Krumbein (1942), Corey
(1949), McNown
et al.
(1951), Wilde (1952), and Schulz
et al.
(1954) experimentally
investigated the effect of particle shape on settling velocity. Based on these experiments,
the Subcommittee on Sedimentation of the U.S. Interagency Committee on Water
Resources (1957) recommended a series of curves shown in Fig. 3.2 to determine the
settling velocity of sediment particles for given particle size, Corey shape factor, and
water temperature. However, this graphical relation is inconvenient to use, because
several interpolations must be conducted to obtain the sought solution. In addition,
all the data used in the calibration were in the range of
R
e
>
3, and the relation was
extended to the range of
R
e
<
3 based on the assumption that it approaches the Stokes
law, Eq. (3.5), for spheres.
Romanovskii (1972) also performed experiments to investigate the effect of particle
shape on settling velocity and obtained a relation of settling velocity with particle size
Figure 3.2
Relation of fall velocity with particle size, shape factor, and temperature
(U.S. Interagency Committee, 1957).
