scholarly journals ON THE DEPOSITIONS PROPERTIES OF ESTUARINE SEDIMENTS

1974 ◽  
Vol 1 (14) ◽  
pp. 72
Author(s):  
Ashish J. Mehta ◽  
Emmanuel Partheniades
Keyword(s):  
Experimental Study ◽  
Shear Strength ◽  
Steady State ◽  
Flow Field ◽  
Annular Channel ◽  
Estuarine Sediments ◽  
Sediment Type ◽  
Cohesive Sediments ◽  
Analytic Treatment ◽  
Turbulent Flow Field

The depositional characteristics of floes of fine cohesive sediments in a turbulent flow field differ distinctly from those of a cohesionless material such as sand. This difference exists because the floe size and shear strength distributions depend on the sediment type as well as the flow condition itself; consequently, the problem of the depositional behavior of these floes is rather complex, and not easily amenable to analytic treatment. The present basic experimental study was carried out in a specially designed annular channel. The derived laws of deposition in relation to the time-rates as well as the steady-state concentrations are described and discussed. The reanalyzed results of other limited investigations agree well with the result of the study.

A Numerical and Experimental Study of Laminar Unsteady Lid-Driven Cavity Flows

2017 ◽  
Author(s):  
K. M. Akyuzlu
Keyword(s):  
Experimental Study ◽  
Steady State ◽  
Flow Field ◽  
Numerical Study ◽  
Working Fluid ◽  
Cavity Flows ◽  
Square Cavity ◽  
Measured Velocity ◽  
Driven Cavity ◽  
Numerical Predictions

An experimental and numerical study was conducted to study unsteady lid-driven cavity flows. More specifically, the development of the circulation patterns inside a square cavity due to the movement of a rigid impermeable lid at constant velocity was observed experimentally and predicted numerically by CFD codes. Particle Image Velocimeter (PIV) technique was used to determine the flow field as it develops from stagnation to steady state inside a one inch (25.4 mm) square cavity driven by an impermeable lid. To avoid the three dimensional effects on the primary vortex, the depth of the cavity is taken to be 5 inches (127 mm). Working fluid is water and it is seeded with hallow glass spheres with 10 microns diameter. Experimental study was conducted for different lid velocities corresponding to Reynolds numbers for laminar to intermittent turbulence. The numerical study was carried out using commercial and in-house CFD codes for the steady state case, and using a commercial CFD code for the unsteady case. The predictions of unsteady flow field inside the two-dimensional square cavity were made using these codes which employ second order accurate (temporally and spatially) implicit numerical schemes. A time and mesh independence study was carried out to determine the optimum mesh size and time increment for the unsteady case study. Comparisons of the numerically predicted and experimentally measured velocity fields are made for steady and unsteady cases. The results indicate that the numerical predictions capture the characteristics of the circulation inside the cavity reasonably well however the magnitude of the velocities are underestimated.

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