A Simplified Analytical Model of a Flash Evaporator Stage Having Channel Flow

1972 ◽  
Vol 94 (3) ◽  
pp. 897-903
Author(s):  
C. H. Coogan ◽  
P. S. Brewster
Keyword(s):  
Thermal Conductivity ◽  
Free Surface ◽  
Analytical Model ◽  
Channel Flow ◽  
Sea Water ◽  
Free Surface Flow ◽  
Equilibrium Temperature ◽  
Surface Flow ◽  
Multi Stage ◽  
Evaporation Ratio

Free surface flow with evaporation such as occurs in multi-stage sea water evaporators is modeled. Using one experimentally determined constant, i.e., the turbulent thermal conductivity of the liquid, permits use of the model in design. Flash down and non-equilibrium temperature differentials are related to the evaporation ratio.

Potential flow solution for a free surface flow past a sudden slope change

2004 ◽  
Vol 31 (4) ◽  
pp. 553-560 ◽  
Author(s):  
A R Zarrati ◽  
Yee-Chung Jin ◽  
A Shanehsaz-zadeh ◽  
F Ahadi
Keyword(s):  
Free Surface ◽  
Pressure Distribution ◽  
Analytical Model ◽  
Potential Flow ◽  
Sudden Change ◽  
Surface Profile ◽  
Free Surface Flow ◽  
Surface Flow ◽  
Flow Past ◽  
Model Predictions

An analytical model was developed to calculate the pressure distribution in a free surface flow past a sudden change in channel slope. A conformal transformation technique was used to solve the problem analytically in a way that there is no need for trial and error to find the location of the free surface. Two methods were employed for this simulation: flow at a corner and free streamline theory. It was shown that free streamline theory is more accurate. Experiments were conducted to verify the ability of the analytical model to calculate the pressure distribution in a channel with a sudden change in slope. Slope changes of 6.22°, 10°, and 15° were tested with various flow discharges. The analytical model predictions of pressure distribution along the channel bed and with depth agreed well with the experimental measurements. Pressures up to 25 times the hydrostatic pressure were experimentally measured near the point of sudden change in slope. These pressures were reproduced by the model. The analytical model predictions of the water surface profile over a ramp in a prototype spillway were compared with those of a numerical model. The comparison showed a good agreement.Key words: pressure distribution, free surface flow, analytical model, chute spillway, aerator ramp, potential flow.

Flotation and free surface flow in a model for subglacial drainage. Part 2. Channel flow

2012 ◽  
Vol 702 ◽  
pp. 157-187 ◽  
Author(s):  
I. J. Hewitt ◽  
C. Schoof ◽  
M. A. Werder
Keyword(s):  
Free Surface ◽  
Channel Flow ◽  
Numerical Solutions ◽  
Flow Line ◽  
Water Pressure ◽  
Free Surface Flow ◽  
High Water ◽  
Surface Flow ◽  
Overburden Pressure ◽  
Subglacial Drainage

AbstractWe present a new model of subglacial drainage incorporating flow in a network of channels and a porous sheet, with water exchange between the two determined by pressure gradients. The sheet represents the average effect of many linked cavities, whilst the channels emerge from individual cavities that enlarge due to dissipation-induced melting. The model distinguishes cases when the water pressure drops to zero, in which case it allows for the drainage space to be only partially filled with water (free surface flow), and when the pressure reaches the ice overburden pressure, in which case it allows for uplift of the ice to whatever extent is needed to accommodate the water (flotation). Numerical solutions are found for a one-dimensional flow-line version of the model. The results capture typically observed or inferred features of subglacial drainage systems, including open channel flow at the ice margin, seasonal channel evolution, and high water pressures and uplift of the ice surface driven by rapid changes in water supply.

scholarly journals Laminar free-surface flow into a vertical cylinder

1975 ◽  
Vol 3 (1) ◽  
pp. 51-68 ◽  
Author(s):  
Thomas G. Smith ◽  
J.O. Wilkes
Keyword(s):  
Free Surface ◽  
Vertical Cylinder ◽  
Free Surface Flow ◽  
Surface Flow

Free-Surface Flow Simulations With Interactively Moving Bodies

2017 ◽  
Author(s):  
Arthur E. P. Veldman ◽  
Henk Seubers ◽  
Peter van der Plas ◽  
Joop Helder
Keyword(s):  
Free Surface ◽  
Free Fall ◽  
Free Surface Flow ◽  
Surface Flow ◽  
Numerical Solution Method ◽  
Flow Simulations ◽  
Floating Object ◽  
Offshore Industry ◽  
Floating Objects ◽  
Moving Bodies

The simulation of free-surface flow around moored or floating objects faces a series of challenges, concerning the flow modelling and the numerical solution method. One of the challenges is the simulation of objects whose dynamics is determined by a two-way interaction with the incoming waves. The ‘traditional’ way of numerically coupling the flow dynamics with the dynamics of a floating object becomes unstable (or requires severe underrelaxation) when the added mass is larger than the mass of the object. To deal with this two-way interaction, a more simultaneous type of numerical coupling is being developed. The paper will focus on this issue. To demonstrate the quasi-simultaneous method, a number of simulation results for engineering applications from the offshore industry will be presented, such as the motion of a moored TLP platform in extreme waves, and a free-fall life boat dropping into wavy water.

Model coupling techniques for free-surface flow problems: Part II

2005 ◽  
Vol 63 (5-7) ◽  
pp. e1897-e1908 ◽  
Author(s):  
E. Miglio ◽  
S. Perotto ◽  
F. Saleri
Keyword(s):  
Free Surface ◽  
Free Surface Flow ◽  
Surface Flow ◽  
Model Coupling ◽  
Flow Problems ◽  
Coupling Techniques
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