TY - JOUR
T1 - Numerical modeling of flow characteristics in a rotating annular flume
AU - Yang, Zhaoqing
AU - Baptista, Ant́nio
AU - Darland, Jeffrey
N1 - Funding Information:
This research was supported in part by the Office of Naval Research grant N00014-96-1-0893 and by the National Science Foundation grant OCE-9807686.
PY - 2000/1
Y1 - 2000/1
N2 - A rotating annular flume (RALF) has been constructed at the Center of Coastal and Land-Margin Research (CCALMR) to study the biogeochemistry of sediment-water interfaces. The flume was designed to allow for evolving, integrated measurements of physical, chemical, and biological parameters, as often as possible in a real-time, computer-controlled mode. Several numerical models have or are being developed/applied to provide a virtual representation of the flume, with the dual objective of assisting the design of experiments and of assessing our level of understanding of processes and process interactions. We will concentrate here on the characterization of the flow in the flume, a basic but interestingly complex problem. The operational challenge is to minimize secondary circulation and lateral variability of shear stress, factors that prevent the flume flow to match the idealized concept of an endless channel flow. Satisfactory minimization of these factors can be achieved by allowing both the top and the bottom rings of the flume to rotate in contrary directions, a concept introduced by earlier research efforts and verified in RALF via Acoustic Doppler Velocimeter (ADV) measurements and 3D numerical modeling. Once logistics (e.g., in the form of the size of the ADV’s sampling volume and of the vertical discretization of the numerical grids) are appropriately handled, observations and model results show good agreement. This agreement legitimates the use of the model as a design and investigative tool, in particular to define optimal rotation ratios of the top and bottom rings. The ratios that minimize secondary flow and lateral variability of shear stress are distinct. This is a logical (generating mechanisms are different) but often not recognized aspect of the operation of annular flumes.
AB - A rotating annular flume (RALF) has been constructed at the Center of Coastal and Land-Margin Research (CCALMR) to study the biogeochemistry of sediment-water interfaces. The flume was designed to allow for evolving, integrated measurements of physical, chemical, and biological parameters, as often as possible in a real-time, computer-controlled mode. Several numerical models have or are being developed/applied to provide a virtual representation of the flume, with the dual objective of assisting the design of experiments and of assessing our level of understanding of processes and process interactions. We will concentrate here on the characterization of the flow in the flume, a basic but interestingly complex problem. The operational challenge is to minimize secondary circulation and lateral variability of shear stress, factors that prevent the flume flow to match the idealized concept of an endless channel flow. Satisfactory minimization of these factors can be achieved by allowing both the top and the bottom rings of the flume to rotate in contrary directions, a concept introduced by earlier research efforts and verified in RALF via Acoustic Doppler Velocimeter (ADV) measurements and 3D numerical modeling. Once logistics (e.g., in the form of the size of the ADV’s sampling volume and of the vertical discretization of the numerical grids) are appropriately handled, observations and model results show good agreement. This agreement legitimates the use of the model as a design and investigative tool, in particular to define optimal rotation ratios of the top and bottom rings. The ratios that minimize secondary flow and lateral variability of shear stress are distinct. This is a logical (generating mechanisms are different) but often not recognized aspect of the operation of annular flumes.
KW - Acoustic Doppler Velocimeter
KW - Center of Coastal and Land-Margin Research
KW - Rotating annular flume
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U2 - 10.1016/S0377-0265(99)00037-8
DO - 10.1016/S0377-0265(99)00037-8
M3 - Article
AN - SCOPUS:0034006499
SN - 0377-0265
VL - 31
SP - 271
EP - 294
JO - Dynamics of Atmospheres and Oceans
JF - Dynamics of Atmospheres and Oceans
IS - 1-4
ER -