TY  - JOUR
T1  - Lateral Behaviour of Velocity and Turbulence Characteristics in Open Channels with
Submerged Heterogeneous Bed
AU - Peter Folorunso, Olatunji AU - Olugbenga Aribisala, James 
JO  - Research Journal of Applied Sciences
VL  - 15
IS  - 3
SP  - 122
EP  - 129
PY  - 2020
DA  - 2001/08/19
SN  - 1815-932x
DO  - rjasci.2020.122.129
UR  - https://makhillpublications.co/view-article.php?doi=rjasci.2020.122.129
KW  - Channels
KW  -velocity
KW  -concentration
KW  -dominant
KW  -stresses
KW  -grass bed
AB  - Most open channels are not comprised of
uniform boundary roughness but instead in any given
cross section consist of different roughness with varying
frictional surface resistance, this heterogeneous bed
roughness is ubiquitous in natural rivers and often
influence and control the mean and turbulent flow
structures in open channels thereby impacting on the
conveyance capacity. This study describes the interaction
of flexible vegetation and gravel bed on the mean and
turbulent flow characteristics of an idealized
heterogeneous open channel modelled using Astroturf
(as grass vegetation) and gravel, the bed interaction is
established alternately at both sides of the flume to form
a partly vegetated open channel in a checkerboard pattern
under a fully submerged condition. Mean velocities and
turbulent properties are measured using the Acoustic
Doppler Velocimeter (ADV). From the measured data, the
cross sectional distribution of velocity and turbulent
properties are obtained. The study shows flow
concentration at the free surface and a reduced mean flow
near bed over the grass bed. Estimated pattern of
secondary flow reveals the interaction between the two
bed roughness. The primary source of velocity shear as
the dominant cause of the increased Reynolds shear
stresses and turbulent activities occurred over the grass
bed.
ER  -