Flume studies

Moog and Jirka then calibrated the lead coefficient and studied the predictive capability of 10 calibrated empirical equations to predict reaeration coefficients that were the result of 331 field studies. The result was surprising, because the best predictive equation was developed by Thackston and Krenkel s (1969) from laboratory flume studies, and the comparison was with field equations. In dimensionless form, Thackston and Krenkel s (1969) cahbrated (multiplying the lead coefficient by 0.69) equation can be converted to a dimensionless form utilizing Sherwood, Schmidt, Reynolds, and Froude numbers ... 

Krone, R.B. (1962) Flume studies of the transport of sediment in estuarial shoaling processes. Univ. of California, Hydraulics and Engineering Lab. and Sanitarian Engineering Research Lab. Berkeley, pp. 110. 

Finelli, C.M. (2000) Velocity and concentration distributions in turbulent odor plumes in the presence of vegetation mimics a flume study, Mar. Ecol. Prog. Ser.207, 297-309. 

Shi, Z., Pethick, J., and Pye, K. (1995) Flow structure in and above the various heights of a saltmarsh canopy A laboratory flume study, Journal of Coastal Research, 11, 1204-1209. 

Four field techniques have been used to estimate the import/export of nutrients between saltmarshes and the adjacent coastal water community budgeting, direct creek studies, flume studies and diffusion chamber studies. The direct tidal creek method is the only one which takes account of the processes in all of the saltmarsh subsystems and hence appears to be the best technique, provided the uncertainties in water discharge are minimised. 

Equations 6 and 7 were used to determine the mass transfer coefficient Ki and K2 for sediments and plants. Detailed studies on 85Sr showed that Ki values ranged from 0.0045 and 0.011 hr 1 for flow conditions having a Reynolds number of 2440 and 3700, respectively (7). Flume studies also indicated that Kp for 85Sr ranged from 664 to 683 dpm/gram per dpm/ml and values of K2 varied from 0.0126 to 0.0322 hr 1 with an average of 0.022 hr 1 (1). 

Peterson, Jr., D.F., Mohanty, P.K. (1960). Flume studies on flow in steep, rough channels. Proc. 

One of the first experiments was a flume study of tsunami runup on a vertical wall to study the effect of complex bathymetry on this highly nonlinear phenomenon. This study was used as Benchmark Problem 3 in the International Workshop on Long Wave Modek to validate numeric models. Kanoglu and Synolakis actively participated and validated their anal3dic method using this data. Bathymetric contours from Revere Beach, MA, were molded in the flume. This model of opportunity was selected to take advantage of a realistic complex bathymetry for a much reduced construction cost. The compound-slope, fixed-bed bathymetry consisted of three different slopes (rise run = 1 53, 1 150, and 1 13) and a flat section in the deep end (Fig. 39.6). The vertical wall was located at the landward end of the 1 13 slope. The water depth in the flat section of the flume measured 21.8cm. 

Krone, R.B. 1962. Flume Studies of the Transport of Sediment in Estuarial Processes. Final Report, Hydraulic Engineering Laboratory and Sanitary Engineering Research Laboratory, University of California, Berkeley. 

To summarise, flume and chamber studies are helpful for investigating the relative importance of surface diffusion, wash off and plant uptake/release from aerial shoots, when used in conjunction with direct tidal creek flux measurements. However, the results from these experiments should not be extrapolated to give a flux value for the marsh as a whole as they do not account for sediment drainage, water column and creek bank processes. 

The difference the field methodology makes to the estimation of the nutrient flux between a saltmarsh and coastal water can be illustrated using studies conducted on North Inlet marsh. South Carolina. Wolaver Spurrier (1988), used the flume technique to estimate the budget for a whole marsh. They concluded that North Inlet marsh imported both phosphate and particulate phosphorus. However, an earlier direct tidal... 

A small-scale ecosystem (research flume) has been used successfully to investigate the transport phenomena of radionuclides added as dissolved inorganics and to study and evaluate the parameters affecting a stream when it is subjected to organic stresses. 

Longitudinal dispersion coefficients, Dx values, in the absence of biomass were calculated for velocities ranging from 0.33 to 3.30 ft/min. The Dx values calculated from the time-concentration curves of the Rhoda-mine B dye studies, under various flow conditions in the flume, follow an empirical relationship in the form... 

Some previous studies, such as those conducted on the Clinch River, have indicated that biomass may be neglected in a mass balance analysis of radionuclides (I, 4). However, when the biomass was extensive in the flume, a significant portion of the radionuclide was retained, at least temporarily (Figure 4). Plants sorbed radionuclides in the order indicated. 

The surface concentration distribution coefficients for sediments K8 and for plants Kp in contact with radioactive contaminated water were formulated and predicted for various radionuclides through aquaria studies and flume experiments. These values reflect the affinity of sediments and plants for various radionuclides. 

We believe the correct parameterizations for most of these processes are not yet discovered. We still do not have appropriate facilities for maintaining and studying biogeochemistry of coral reefs. The understanding of their biogeochemistry will not advance unless appropriate flumes and mesocosms are constructed. It will take some national or international shared research facility at the appropriate place to make such advances. 

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