Low-Dimensional Modeling of Transient Two-Phase Flow in Pipelines

2016 ◽  
Vol 138 (10) ◽  
Author(s):  
Amine Meziou ◽  
Majdi Chaari ◽  
Matthew Franchek ◽  
Rafik Borji ◽  
Karolos Grigoriadis ◽  
...  
Keyword(s):  
Steady State ◽  
Multiphase Flow ◽  
Transmission Line ◽  
Transmission Lines ◽  
Mechanistic Model ◽  
Phase Flow ◽  
Liquid Holdup ◽  
Two Phase ◽  
Low Dimensional ◽  
State Pressure

Presented are reduced-order models of one-dimensional transient two-phase gas–liquid flow in pipelines. The proposed model is comprised of a steady-state multiphase flow mechanistic model in series with a transient single-phase flow model in transmission lines. The steady-state model used in our formulation is a multiphase flow mechanistic model. This model captures the steady-state pressure drop and liquid holdup estimation for all pipe inclinations. Our implementation of this model will be validated against the Stanford University multiphase flow database. The transient portion of our model is based on a transmission line modal model. The model parameters are realized by developing equivalent fluid properties that are a function of the steady-state pressure gradient and liquid holdup identified through the mechanistic model. The model ability to reproduce the dynamics of multiphase flow in pipes is evaluated upon comparison to olga, a commercial multiphase flow dynamic code, using different gas volume fractions (GVF). The two models show a good agreement of the steady-state response and the frequency of oscillation indicating a similar estimation of the transmission line natural frequency. However, they present a discrepancy in the overshoot values and the settling time due to a difference in the calculated damping ratio. The utility of the developed low-dimensional model is the reduced computational burden of estimating transient multiphase flow in transmission lines, thereby enabling real-time estimation of pressure and flow rate.

Liquid Holdup Discretized Solution's Existence and Uniqueness Using a Simplified Averaged One-Dimensional Upward Two-Phase Flow Transient Model

2017 ◽  
Vol 139 (8) ◽  
Author(s):  
Ala E. Omrani ◽  
Matthew A. Franchek ◽  
Karolos Grigoriadis ◽  
Reza Tafreshi
Keyword(s):  
Steady State ◽  
Numerical Model ◽  
Multiphase Flow ◽  
Existence And Uniqueness ◽  
Flow Dynamics ◽  
Phase Flow ◽  
Liquid Holdup ◽  
Two Phase ◽  
One Dimensional ◽  
Order Polynomial

This article presents a one-dimensional numerical model for vertical upward multiphase flow dynamics in a pipeline. A quasi-steady-state condition is used for the gas phase as well as liquid and gas momentum equations. A second-order polynomial for homogeneous flows and a sixth-order polynomial for separated flows are derived to determine the two-phase flow dynamics, assuming that the gas flow mass is conserved. The polynomials are formulated based on the homogenous and separate flows' momentum equation and the homogeneous flows' rise velocity equation and their zeros are the flow actual liquid holdup. The modeling polynomial approach enables the study of the polynomial liquid holdup zeros existence and uniqueness and as a result the design of a stable numerical model in terms of its outputs. The one-dimensional solution of the flow for the case of slug and bubble flow is proven to exist and to be unique when the ratio of the pipe node length to the time step is inferior to a specific limit. For the annular flow case, constraints on the inlet gas superficial velocity and liquid to gas density ratio show that the existence is ensured while the uniqueness may be violated. Simulations of inlet pressure under transient condition are provided to illustrate the numerical model predictions. The model steady-state results are validated against experimental measurements and previously developed and validated multiphase flow mechanistic model.

scholarly journals An Explicit Analytical Solution for Transient Two-Phase Flow in Inclined Fluid Transmission Lines

Fluids ◽  
2021 ◽  
Vol 6 (9) ◽  
pp. 300
Author(s):  
Taoufik Wassar ◽  
Matthew A. Franchek ◽  
Hamdi Mnasri ◽  
Yingjie Tang
Keyword(s):  
Steady State ◽  
Analytical Model ◽  
Transmission Lines ◽  
Single Phase ◽  
Flow Model ◽  
Two Phase Flow ◽  
Mechanistic Model ◽  
Phase Flow ◽  
Single Phase Flow ◽  
Two Phase

Due to the complex nonlinearity characteristics, analytical modeling of compressible flow in inclined transmission lines remains a challenge. This paper proposes an analytical model for one-dimensional flow of a two-phase gas-liquid fluid in inclined transmission lines. The proposed model is comprised of a steady-state two-phase flow mechanistic model in-series with a dynamic single-phase flow model. The two-phase mechanistic model captures the steady-state pressure drop and liquid holdup properties of the gas-liquid fluid. The developed dynamic single-phase flow model is an analytical model comprised of rational polynomial transfer functions that are explicitly functions of fluid properties, line geometry, and inclination angle. The accuracy of the fluid resonant frequencies predicted by the transient flow model is precise and not a function of transmission line spatial discretization. Therefore, model complexity is solely a function of the number of desired modes. The dynamic single-phase model is applicable for under-damped and over-damped systems, laminar, and turbulent flow conditions. The accuracy of the overall two-phase flow model is investigated using the commercial multiphase flow dynamic code OLGA. The mean absolute error between the two models in step response overshoot and settling time is less than 8% and 2 s, respectively.

Performance of Two-Phase Flow Models on the Prediction of Oscillatory Flow Conditions

2016 ◽  
Author(s):  
Catalina Posada ◽  
Paulo Waltrich
Keyword(s):  
Experimental Data ◽  
Steady State ◽  
Pressure Gradient ◽  
Two Phase Flow ◽  
Percentage Error ◽  
Phase Flow ◽  
Liquid Holdup ◽  
Two Phase ◽  
Flow Models ◽  
Absolute Percentage Error

The present investigation presents a comparative study between two-phase flow models and experimental data. Experimental data was obtained using a 42 m long, 0.05 m ID tube system. The experimental data include conditions for pressures ranging from 1.2 to 2.8 bara, superficial liquid velocities 0.02–0.3 m/s, and superficial gas velocity ranges 0.17–26 m/s. The experimental data was used to evaluate the performance of steady-state empirical and mechanistic models while estimating liquid holdup and pressure gradient under steady-state and oscillatory conditions. The purpose of this analysis is first to evaluate the accuracy of the models predicting the liquid holdup and pressure gradient under steady-state conditions. Then, after evaluating the models under state-steady conditions, the same models are used to predict the same parameters for oscillatory and periodic conditions for similar gas and liquid velocities. The transient multiphase flow simulator OLGA, which has been widely used in the oil and gas industry, was implemented to model one oscillatory case to evaluate the prediction improvement while using a transient instead of a steady-state model to predict oscillatory flows. For the model with best performance for steady-state pressure gradient prediction, the absolute percentage error is 12% for Uls = 0.02 m/s and 5% for Uls = 0.3. For oscillatory conditions, the absolute percentage error is 30% for Uls = 0.02 m/s and 4% for Uls = 0.3. OLGA results underpredict the experimental pressure gradient under oscillatory conditions with errors up to 30%. Therefore, it was possible to conclude that the models can predict the average of the oscillatory data almost as well as for steady-state conditions.

A Unified Mechanistic Model for Steady-State Two-Phase Flow in Wellbores and Pipelines

1999 ◽  
Author(s):  
L.E. Gomez ◽  
O. Shoham ◽  
Z. Schmidt ◽  
R.N. Chokshi ◽  
A. Brown ◽  
...  
Keyword(s):  
Steady State ◽  
Two Phase Flow ◽  
Mechanistic Model ◽  
Phase Flow ◽  
Two Phase

Unified Mechanistic Model for Steady-State Two-Phase Flow: Horizontal to Vertical Upward Flow

SPE Journal ◽  
2000 ◽  
Vol 5 (03) ◽  
pp. 339-350 ◽  
Author(s):  
L.E. Gomez ◽  
Ovadia Shoham ◽  
Zelimir Schmidt ◽  
R.N. Chokshi ◽  
Tor Northug
Keyword(s):  
Steady State ◽  
Two Phase Flow ◽  
Mechanistic Model ◽  
Phase Flow ◽  
Upward Flow ◽  
Two Phase

An Optimized Artificial Neural Network Unifying Model for Steady-State Liquid Holdup Estimation in Two-Phase Gas–Liquid Flow

2018 ◽  
Vol 140 (10) ◽  
Author(s):  
Majdi Chaari ◽  
Abdennour C. Seibi ◽  
Jalel Ben Hmida ◽  
Afef Fekih
Keyword(s):  
Neural Network ◽  
Artificial Neural Network ◽  
Steady State ◽  
Prediction Accuracy ◽  
Two Phase Flow ◽  
Flow Patterns ◽  
Phase Flow ◽  
Liquid Holdup ◽  
Two Phase ◽  
Artificial Neural

Simplifying assumptions and empirical closure relations are often required in existing two-phase flow modeling based on first-principle equations, hence limiting its prediction accuracy and in some instances compromising safety and productivity. State-of-the-art models used in the industry still include correlations that were developed in the sixties, whose prediction performances are at best acceptable. To better improve the prediction accuracy and encompass all pipe inclinations and flow patterns, we propose in this paper an artificial neural network (ANN)-based model for steady-state two-phase flow liquid holdup estimation in pipes. Deriving the best input combination among a large reservoir of dimensionless Π groups with various fluid properties, pipe characteristics, and operating conditions is a laborious trial-and-error procedure. Thus, a self-adaptive genetic algorithm (GA) is proposed in this work to both ease the computational complexity associated with finding the elite ANN model and lead to the best prediction accuracy of the liquid holdup. The proposed approach was implemented using the Stanford multiphase flow database (SMFD), chosen for being among the largest and most complete databases in the literature. The performance of the proposed approach was further compared to that of two prominent models, namely a standard empirical correlation-based model and a mechanistic model. The obtained results along with the comparison analysis confirmed the enhanced accuracy of the proposed approach in predicting liquid holdup for all pipe inclinations and fluid flow patterns.

scholarly journals A relaxation scheme for a hyperbolic multiphase flow model

2019 ◽  
Vol 53 (5) ◽  
pp. 1763-1795 ◽  
Author(s):  
Khaled Saleh
Keyword(s):  
Multiphase Flow ◽  
Flow Model ◽  
Two Phase Flow ◽  
Equations Of State ◽  
Energy Inequality ◽  
Approximation Error ◽  
Finite Volume Scheme ◽  
Phase Flow ◽  
Two Phase ◽  
Relaxation Scheme

This article is the first of two in which we develop a relaxation finite volume scheme for the convective part of the multiphase flow models introduced in the series of papers (Hérard, C.R. Math. 354 (2016) 954–959; Hérard, Math. Comput. Modell. 45 (2007) 732–755; Boukili and Hérard, ESAIM: M2AN 53 (2019) 1031–1059). In the present article we focus on barotropic flows where in each phase the pressure is a given function of the density. The case of general equations of state will be the purpose of the second article. We show how it is possible to extend the relaxation scheme designed in Coquel et al. (ESAIM: M2AN 48 (2013) 165–206) for the barotropic Baer–Nunziato two phase flow model to the multiphase flow model with N – where N is arbitrarily large – phases. The obtained scheme inherits the main properties of the relaxation scheme designed for the Baer–Nunziato two phase flow model. It applies to general barotropic equations of state. It is able to cope with arbitrarily small values of the statistical phase fractions. The approximated phase fractions and phase densities are proven to remain positive and a fully discrete energy inequality is also proven under a classical CFL condition. For N = 3, the relaxation scheme is compared with Rusanov’s scheme, which is the only numerical scheme presently available for the three phase flow model (see Boukili and Hérard, ESAIM: M2AN 53 (2019) 1031–1059). For the same level of refinement, the relaxation scheme is shown to be much more accurate than Rusanov’s scheme, and for a given level of approximation error, the relaxation scheme is shown to perform much better in terms of computational cost than Rusanov’s scheme. Moreover, contrary to Rusanov’s scheme which develops strong oscillations when approximating vanishing phase solutions, the numerical results show that the relaxation scheme remains stable in such regimes.

A comparative study of MHD fluid-particle suspension induced by metachronal wave under the effects of lubricated walls

2021 ◽  
pp. 2150204
Author(s):  
Mubbashar Nazeer ◽  
Farooq Hussain ◽  
Laiba Shabbir ◽  
Adila Saleem ◽  
M. Ijaz Khan ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Magnetic Fields ◽  
Multiphase Flow ◽  
Thermal Radiation ◽  
Newtonian Fluid ◽  
Closed Form Solution ◽  
Casson Fluid ◽  
Form Solution ◽  
Phase Flow ◽  
Two Phase

In this paper, the two-phase flow of non-Newtonian fluid is investigated. The main source of the flow is metachronal waves which are caused by the back and forth motion of cilia attached to the opposite walls of the channel. Magnetohydrodynamics (MHD) of Casson fluid experience the effects of transverse magnetic fields incorporated with the slippery walls of the channel. Thermal effects are examined by taking Roseland’s approximation and application of thermal radiation into account. The heat transfer through the multiphase flow of non-Newtonian fluid is further, compared with Newtonian bi-phase flow. Since the main objective of the current study is to analyze heat transfer through an MHD multiphase flow of Casson fluid. The two-phase heated flow of non-Newtonian fluid is driven by cilia motion results in nonlinear and coupled differential equations which are transformed and subsequently, integrated subject to slip boundary conditions. A closed-form solution is eventually obtained form that effectively describes the flow dynamics of multiphase flow. A comprehensive parametric study is carried out which highlights the significant contribution of pertinent parameters of the heat transfer of Casson multiphase flow. It is inferred that lubricated walls and magnetic fields hamper the movement of multiphase flow. It is noted that a sufficient amount of additional thermal energy moves into the system, due to the Eckert number and Prandtl number. While thermal radiation acts differently by expunging the heat transfer. Moreover, Casson multiphase flow is a more suitable source of heat transfer than Newtonian multiphase flow.

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