scholarly journals Flow patterns of shallow Palic Lake induced by the dominant winds

2012 ◽  
Vol 10 (1) ◽  
pp. 55-67
Author(s):  
Ljubomir Budinski ◽  
Djula Fabian
Keyword(s):  
Numerical Model ◽  
Flow Pattern ◽  
Coriolis Force ◽  
Wind Direction ◽  
Driving Forces ◽  
Open Water ◽  
Flow Patterns ◽  
Two Dimensional ◽  
Lake Model ◽  
Double Gyre

Studies of lake currents have highlighted that in case of stagnant waters winds are the dominant driving forces. This study is dealing with the influence of dominant winds on the flow pattern of Palic Lake. Action of steady winds of different directions has been tested on the lake by means of a two dimensional numerical model, while in addition to winds all other permanent factors like actual bathymetry, inflow and outflow as well the Coriolis force have been accounted for. The experiments have revealed that winds of different directions created corresponding characteristic flow patterns (in base plot), which were similar in cases of winds having opposite directions. However, in such cases the direction of flow was opposite. Moreover, the Palic Lake model produced the well known double-gyre flow pattern: in the coastal strip the direction of the current corresponded to the wind direction, while it was opposite in the domain of open water.

scholarly journals FLOW COMPUTATIONS NEARBY A STORM SURGE BARRIER UNDER CONSTRUCTION WITH TWO-DIMENSIONAL NUMERICAL MODELS

1986 ◽  
Vol 1 (20) ◽  
pp. 143
Author(s):  
H.E. Klatter ◽  
J.M.C. Dijkzeul ◽  
G. Hartsuiker ◽  
L. Bijlsma
Keyword(s):  
Numerical Model ◽  
Storm Surge ◽  
Field Data ◽  
Numerical Models ◽  
Flow Patterns ◽  
Scale Model ◽  
Energy Losses ◽  
Local Energy ◽  
Two Dimensional ◽  
Physical Scale

This paper discusses the application of two-dimensional tidal models to the hydraulic research for the storm surge barrier in the Eastern Scheldt in the Netherlands. At the site of the barrier local energy losses dominate the flow. Three methods are discussed for dealing with these energy losses in a numerical model based on the long wave equations. The construction of the storm surge barrier provided extensive field data for various phases of the construction of the barrier and these field data are used as a test case for the computation at methods developed. One method is preferred since it gives good agreement between computations and field data. The two-dimensional flow patterns, the discharge and the head-difference agree well,, The results of scale model tests were also available for comparison. This comparison demonstrated that depth-averaged velocities, computed by a two-dimensional numerical model, are as accurate as values obtained from a large physical scale model. Even compicated flow patterns with local energy losses and sharp velocity gradients compared well.

DISCRETE PARTICLE SIMULATION OF FLOW PATTERNS IN TWO-DIMENSIONAL GAS FLUIDIZED BEDS

1993 ◽  
Vol 07 (09n10) ◽  
pp. 1889-1898 ◽  
Author(s):  
T. TANAKA ◽  
T. KAWAGUCHI ◽  
Y. TSUJI
Keyword(s):  
Flow Pattern ◽  
Gas Flow ◽  
Distinct Element ◽  
Flow Patterns ◽  
Particle Simulation ◽  
Two Dimensional ◽  
Particle Mixing ◽  
Central Nozzle ◽  
Discrete Particle Simulation ◽  
Gas Fluidized Beds

The flow patterns in two-dimensional gas fluidized bed were simulated numerically by the Distinct Element Method, Gas is issued through the entire width of the base with uniform velocity. Several flow patterns, such as slugging and bubbling, are observed in the results. As the gas flow rate increases, the flow pattern changes from slugging to bubbling. It is confirmed that particle mixing is promoted by bubbling. The flow pattern of bubbling is irregular in comparison with the case of gas injection through a central nozzle which was simulated in our previous study.

Investigation of two-dimensional nonstationary processes of outflow a gas-saturated liquid from axisymmetric vessels

2012 ◽  
Vol 9 (1) ◽  
pp. 47-52
Author(s):  
R.Kh. Bolotnova ◽  
V.A. Buzina
Keyword(s):  
Comparative Analysis ◽  
Numerical Model ◽  
Liquid Mixture ◽  
Phase Model ◽  
Test Problems ◽  
Two Dimensional ◽  
Nonstationary Processes ◽  
Saturated Liquid ◽  
Two Phase ◽  
One Dimensional

The two-dimensional and two-phase model of the gas-liquid mixture is constructed. The validity of numerical model realization is justified by using a comparative analysis of test problems solution with one-dimensional calculations. The regularities of gas-saturated liquid outflow from axisymmetric vessels for different geometries are established.

scholarly journals Flow Pattern Map of Flow Boiling in a Rectangular Channel Filled with Porous Media

Energies ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2440
Author(s):  
Youngwoo Kim ◽  
Dae Yeon Kim ◽  
Kyung Chun Kim
Keyword(s):  
Porous Media ◽  
Flow Pattern ◽  
Flow Regime ◽  
Annular Flow ◽  
Flow Boiling ◽  
Rectangular Channel ◽  
Flow Patterns ◽  
Flow Pattern Map ◽  
Mist Flow ◽  
Churn Flow

A flow visualization study was carried out for flow boiling in a rectangular channel filled with and without metallic random porous media. Four main flow patterns are observed as intermittent slug-churn flow, churn-annular flow, annular-mist flow, and mist flow regimes. These flow patterns are clearly classified based on the high-speed images of the channel flow. The results of the flow pattern map according to the mass flow rate were presented using saturation temperatures and the materials of porous media as variables. As the saturation temperatures increased, the annular-mist flow regime occupied a larger area than the lower saturation temperatures condition. Therefore, the churn flow regime is narrower, and the slug flow more quickly turns to annular flow with the increasing vapor quality. The pattern map is not significantly affected by the materials of porous media.

scholarly journals Influence of the North Branch of the Qingshuigou River on the Lower Reaches of Yellow River Based on Two-dimensional Numerical Model

2021 ◽  
Vol 1885 (2) ◽  
pp. 022043
Author(s):  
Caodong Jiang ◽  
Liangchao Ma ◽  
Dongfeng Li ◽  
Hongwu Zhang ◽  
Zihao Li
Keyword(s):  
Numerical Model ◽  
Yellow River ◽  
Two Dimensional ◽  
The North

Two-Phase Flow and Heat Transfer in Rectangular Micro-Channels

2003 ◽  
Author(s):  
Weilin Qu ◽  
Seok-Mann Yoon ◽  
Issam Mudawar
Keyword(s):  
Heat Transfer ◽  
Pressure Drop ◽  
Flow Pattern ◽  
Two Phase Flow ◽  
Flow Patterns ◽  
Heat Sinks ◽  
Phase Flow ◽  
Micro Channel ◽  
Two Phase ◽  
Micro Channels

Knowledge of flow pattern and flow pattern transitions is essential to the development of reliable predictive tools for pressure drop and heat transfer in two-phase micro-channel heat sinks. In the present study, experiments were conducted with adiabatic nitrogen-water two-phase flow in a rectangular micro-channel having a 0.406 × 2.032 mm cross-section. Superficial velocities of nitrogen and water ranged from 0.08 to 81.92 m/s and 0.04 to 10.24 m/s, respectively. Flow patterns were first identified using high-speed video imaging, and still photos were then taken for representative patterns. Results reveal that the dominant flow patterns are slug and annular, with bubbly flow occurring only occasionally; stratified and churn flow were never observed. A flow pattern map was constructed and compared with previous maps and predictions of flow pattern transition models. Annual flow is identified as the dominant flow pattern for conditions relevant to two-phase micro-channel heat sinks, and forms the basis for development of a theoretical model for both pressure drop and heat transfer in micro-channels. Features unique to two-phase micro-channel flow, such as laminar liquid and gas flows, smooth liquid-gas interface, and strong entrainment and deposition effects are incorporated into the model. The model shows good agreement with experimental data for water-cooled heat sinks.

scholarly journals Footprints of a flapping wing

2017 ◽  
Vol 818 ◽  
pp. 1-4 ◽  
Author(s):  
Jun Zhang
Keyword(s):  
Flow Pattern ◽  
External Force ◽  
Thrust Force ◽  
Flow Patterns ◽  
Flapping Wing ◽  
Flapping Wings ◽  
Left Behind ◽  
Full Picture

Birds have to flap their wings to generate the needed thrust force, which powers them through the air. But how exactly do flapping wings create such force, and at what amplitude and frequency should they operate? These questions have been asked by many researchers. It turns out that much of the secret is hidden in the wake left behind the flapping wing. Exemplified by the study of Andersen et al. (J. Fluid Mech., vol. 812, 2017, R4), close examination of the flow pattern behind a flapping wing will inform us whether the wing is towed by an external force or able to generate a net thrust force by itself. Such studies are much like looking at the footprints of terrestrial animals as we infer their size and weight, figuring out their walking and running gaits. A map that displays the collection of flow patterns after a flapping wing, using flapping frequency and amplitude as the coordinates, offers a full picture of its flying ‘gaits’.

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