Numerical Modelling of Stratified Gas-Liquid Flow in Inclined Circular Pipes

2009 ◽  
Author(s):  
Jose´ L. H. Faccini ◽  
Paulo A. B. De Sampaio ◽  
Jian Su
Keyword(s):  
Pressure Gradient ◽  
Liquid Flow ◽  
Numerical Solutions ◽  
Stokes Equations ◽  
Numerical Data ◽  
Downward Flow ◽  
Liquid Height ◽  
Circular Pipes ◽  
Linear Differential ◽  
Gas Liquid Flow

In this paper, a fully developed stratified gas-liquid flow in inclined circular pipes is numerically modeled. The model is applied on a stratified gas-liquid downward flow with smooth and horizontal interface, in pipes with inclination angles varying from 0 to −10 degrees. A system of non-linear differential equations, consisting of the Reynolds averaged Navier-Stokes equations with the κ – ω turbulence model, are solved by using an inner iteration loop based on the Newton-Raphson scheme and the finite element method. Numerical solutions are obtained for the liquid height and pressure gradient which were compared with experimental and numerical data. An excellent agreement with the experimental data was obtained, leading to conclusion that the present model is adequate to simulate the stratified gas-liquid downward flow, and it can be used to estimate the flow parameters such as the liquid height and pressure gradient.

The structure of two-dimensional separation

1990 ◽  
Vol 220 ◽  
pp. 397-411 ◽  
Author(s):  
Laura L. Pauley ◽  
Parviz Moin ◽  
William C. Reynolds
Keyword(s):  
Boundary Layer ◽  
Pressure Gradient ◽  
Numerical Solutions ◽  
Stokes Equations ◽  
Adverse Pressure Gradient ◽  
Navier Stokes ◽  
Stream Velocity ◽  
Two Dimensional ◽  
Navier Stokes Equations ◽  
Shedding Frequency

The separation of a two-dimensional laminar boundary layer under the influence of a suddenly imposed external adverse pressure gradient was studied by time-accurate numerical solutions of the Navier–Stokes equations. It was found that a strong adverse pressure gradient created periodic vortex shedding from the separation. The general features of the time-averaged results were similar to experimental results for laminar separation bubbles. Comparisons were made with the ‘steady’ separation experiments of Gaster (1966). It was found that his ‘bursting’ occurs under the same conditions as our periodic shedding, suggesting that bursting is actually periodic shedding which has been time-averaged. The Strouhal number based on the shedding frequency, local free-stream velocity, and boundary-layer momentum thickness at separation was independent of the Reynolds number and the pressure gradient. A criterion for onset of shedding was established. The shedding frequency was the same as that predicted for the most amplified linear inviscid instability of the separated shear layer.

COCURRENT GAS-LIQUID FLOW IN METAL FOAM: AN EXPERIMENTAL INVESTIGATION OF PRESSURE GRADIENT

2010 ◽  
Vol 13 (6) ◽  
pp. 497-510 ◽  
Author(s):  
Jean-Philippe Bonnet ◽  
Frederic Topin ◽  
Jerome Vicente ◽  
Lounes Tadrist
Keyword(s):  
Experimental Investigation ◽  
Pressure Gradient ◽  
Liquid Flow ◽  
Metal Foam ◽  
Gas Liquid Flow

Numerical Simulation of Flows Driven by a Torsionally Oscillating Lid in a Square Cavity

1992 ◽  
Vol 114 (2) ◽  
pp. 143-151 ◽  
Author(s):  
Reima Iwatsu ◽  
Jae Min Hyun ◽  
Kunio Kuwahara
Keyword(s):  
Thin Layer ◽  
Numerical Solutions ◽  
Stokes Equations ◽  
Fluid Motion ◽  
Numerical Data ◽  
Navier Stokes ◽  
Physical Parameters ◽  
Phase Lag ◽  
Two Dimensional ◽  
Force Coefficient

Numerical studies were made of the flow of a viscous fluid in a two-dimensional square container. The flows are driven by the top sliding wall, which executes sinusoidal oscillations. Numerical solutions were acquired by solving the time-dependent, two-dimensional incompressible Navier-Stokes equations. Results are presented for wide ranges of two principal physical parameters, i.e., Re, the Reynolds number and ω′, the nondimensional frequency of the lid oscillation. Comprehensive details of the flow-structure are presented. When ω′ is small, the flow bears qualitative similarity to the well-documented steady driven-cavity flow. The flow in the bulk of cavity region is affected by the motion of the sliding upper lid. On the contrary, when ω′ is large, the fluid motion tends to be confined within a thin layer near the oscillating lid. In this case, the flow displays the characteristic features of a thin-layer flow. When ω′ is intermediate, ω′ ~ O(1), the effect of the side walls is pronounced; the flow pattern reveals significant changes between the low-Re and high-Re limits. Streamline plots are constructed for different parameter spaces. Physically informative interpretations are proposed which help gain physical insight into the dynamics. The behavior of the force coefficient Cf has been examined. The magnitude and phase lag of Cf are determined by elaborate post-processings of the numerical data. By utilizing the wealth of the computational results, characterizations of Cf as functions of Re and ω′ are attempted. These are in qualitative consistency with the theoretical predictions for the limiting parameter values.

Capsular flow in pipelines

1972 ◽  
Vol 56 (1) ◽  
pp. 49-59 ◽  
Author(s):  
A. E. Vardy ◽  
M. I. G. Bloor ◽  
J. A. Fox
Keyword(s):  
Reynolds Number ◽  
Pressure Gradient ◽  
Numerical Solutions ◽  
Stokes Equations ◽  
Steady Motion ◽  
Reynolds Numbers ◽  
Navier Stokes ◽  
Hydraulic Pressure ◽  
Central Difference ◽  
Navier Stokes Equations

The problem considered is that of the steady motion of a series of neutrally buoyant, flat-faced, rigid, cylindrical capsules along the axis of a pipeline under the influence of a hydraulic pressure gradient. The Navier-Stokes equations are non-dimensionalized and expressed in central-difference form. Numerical solutions are found by the method of relaxation for Reynolds numbers up to 20 000 and a close agreement is obtained with readings from a laboratory apparatus for Reynolds numbers up to 2200.The flow is examined in detail and the existence of toroidal vortices between successive capsules is demonstrated. Their shape is shown to be increasingly influenced by inertial forces as the Reynolds number increases, but the overall pressure gradient is not greatly dependent on the Reynolds number.

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