An in-depth study on the implementation aspect of unified time integrators in reactive two-phase flows with consistent time level

2019 ◽  
Vol 29 (2) ◽  
pp. 617-639 ◽  
Author(s):  
Tao Xue ◽  
Xiaobing Zhang ◽  
K.K. Tamma
Keyword(s):  
Two Phase Flow ◽  
Time Integration ◽  
General Purpose ◽  
Second Order ◽  
Phase Flow ◽  
Time Level ◽  
Two Phase Flows ◽  
Two Phase ◽  
Content Type ◽  
Time Accuracy

Purpose A consistent implementation of the general computational framework of unified second-order time accurate integrators via the well-known GSSSS framework in conjunction with the traditional Finite Difference Method is presented to improve the numerical simulations of reactive two-phase flows. Design/methodology/approach In the present paper, the phase interaction evaluation in the present implementation of the reactive two-phase flows has been derived and implemented to preserve the consistency of the correct time level evaluation during the time integration process for solving the two phase flow dynamics with reactions. Findings Numerical examples, including the classical Sod shock tube problem and a reactive two-phase flow problem, are exploited to validate the proposed time integration framework and families of algorithms consistently to second order in time accuracy; this is in contrast to the traditional practices which only seem to obtain first-order time accuracy because of the inconsistent time level implementation with respect to the interaction of two phases. The comparisons with the traditional implementation and the advantages of the proposed implementation are given in terms of the improved numerical accuracy in time. The proposed approaches provide a correct numerical simulation implementation to the reactive two-phase flows and can obtain better numerical stability and computational features. Originality/value The new algorithmic framework and the consistent time level evaluation extended with the GS4 family encompasses a multitude of past and new schemes and offers a general purpose and unified implementation for fluid dynamics.

Solving a mixture model of two-phase flow with velocity non-equilibrium using WENO wavelet methods

2018 ◽  
Vol 28 (9) ◽  
pp. 2052-2071 ◽  
Author(s):  
Alice de Jesus Kozakevicius ◽  
Dia Zeidan ◽  
Alex A. Schmidt ◽  
Stefan Jakobsson
Keyword(s):  
Two Phase Flow ◽  
Weno Scheme ◽  
Phase Flow ◽  
Two Phase Flows ◽  
Time Step ◽  
Two Phase ◽  
Content Type ◽  
Conservative Form ◽  
Wavelet Methods ◽  
Non Equilibrium

Purpose The purpose of this work is to present the implementation of weighted essentially non-oscillatory (WENO) wavelet methods for solving multiphase flow problems. The particular interest is gas–liquid two-phase mixture with velocity non-equilibrium. Numerical simulations are carried out on different scenarios of one-dimensional Riemann problems for gas–liquid flows. Results are validated and qualitatively compared with solutions provided by other standard numerical methods. Design/methodology/approach This paper extends the framework of WENO wavelet adaptive method to a fully hyperbolic two-phase flow model in a conservative form. The grid adaptivity in each time step is provided by the application of a thresholded interpolating wavelet transform. This facilitates the construction of a small yet effective sparse point representation of the solution. The method of Lax–Friedrich flux splitting is used to resolve the spatial operator in which the flux derivatives are approximated by the WENO scheme. Findings Hyperbolic models of two-phase flow in conservative form are efficiently solved, as shocks and rarefaction waves are precisely captured by the chosen methodology. Substantial computational gains are obtained through the grid reduction feature while maintaining the quality of the solutions. The results indicate that WENO wavelet methods are robust and sufficient to accurately simulate gas–liquid mixtures. Originality/value Resolution of two-phase flows is rarely studied using WENO wavelet methods. It is the first time such a study on the relative velocity is reported in two-phase flows using such methods.

A Combined Eulerian and Lagrangian Method for Prediction of Evaporating Sprays

2002 ◽  
Vol 124 (3) ◽  
pp. 481-488 ◽  
Author(s):  
M. Burger ◽  
G. Klose ◽  
G. Rottenkolber ◽  
R. Schmehl ◽  
D. Giebert ◽  
...  
Keyword(s):  
Two Phase Flow ◽  
Initial Conditions ◽  
Three Dimensional ◽  
Lagrangian Method ◽  
Phase Flow ◽  
Two Phase Flows ◽  
Two Phase ◽  
Lagrangian Methods ◽  
Eulerian Method ◽  
Lagrangian Modeling

Polydisperse sprays in complex three-dimensional flow systems are important in many technical applications. Numerical descriptions of sprays are used to achieve a fast and accurate prediction of complex two-phase flows. The Eulerian and Lagrangian methods are two essentially different approaches for the modeling of disperse two-phase flows. Both methods have been implemented into the same computational fluid dynamics package which is based on a three-dimensional body-fitted finite volume method. Considering sprays represented by a small number of droplet starting conditions, the Eulerian method is clearly superior in terms of computational efficiency. However, with respect to complex polydisperse sprays, the Lagrangian technique gives a higher accuracy. In addition, Lagrangian modeling of secondary effects such as spray-wall interaction enhances the physical description of the two-phase flow. Therefore, in the present approach the Eulerian and the Lagrangian methods have been combined in a hybrid method. The Eulerian method is used to determine a preliminary solution of the two-phase flow field. Subsequently, the Lagrangian method is employed to improve the accuracy of the first solution using detailed sets of initial conditions. Consequently, this combined approach improves the overall convergence behavior of the simulation. In the final section, the advantages of each method are discussed when predicting an evaporating spray in an intake manifold of an internal combustion engine.

Solid–liquid two-phase flow and erosion calculation of butterfly valves at small opening based on DEM method

2020 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Benliang Xu ◽  
Zuchao Zhu ◽  
Zhe Lin ◽  
Dongrui Wang
Keyword(s):  
Peer Review ◽  
Two Phase Flow ◽  
Solid Particles ◽  
Phase Flow ◽  
Butterfly Valve ◽  
Two Phase ◽  
Content Type ◽  
Small Opening ◽  
Solid Liquid ◽  
The Impact

Purpose The study aims to decrease the effect of solid particles on a butterfly valve, which will cause seal failure and leakage, providing a reference for anti-wear design. Design/methodology/approach In this paper, computational fluid dynamics discrete element method (CFD-DEM) simulation was conducted to study the solid–liquid two-phase flow characteristics and erosion characteristics of a butterfly valve with a different opening. Findings Abrasion at 10% opening is affected by high-speed jets in upper and lower parts of the pipeline, where the erosion is intense. The impact of the jet on the upper part of 20% opening begins to weaken. With the top backflow vortex disappearing, the effect of lower jet is enhanced. Meanwhile, the bottom backflow vortex phenomenon is obvious, and the abrasion position moves downward. At 30% opening, the velocity is further weakened, and the circulation effect of lower flow channel is more obvious than that of the upper one. Originality/value It is the first time to use DEM to investigate the two-phase flow and erosion characteristics at a small opening of a butterfly valve, considering the effect of inter-particle collision. Therefore, this study carries on the thorough analysis and discussion. At the same opening degree, with increasing of the particle size, the abrasion of valve frontal surface increases when the size is less than 150 µm and decreases when it is greater than 150 µm. For the valve backflow surface, this boundary value becomes 200 µm. Peer review The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-07-2020-0264/

A novel gas/liquid two-phase flow imaging method through electrical resistance tomography with DDELM-AE sparse dictionary

Sensor Review ◽  
2020 ◽  
Vol 40 (4) ◽  
pp. 407-420
Author(s):  
Bo Li ◽  
Jian ming Wang ◽  
Qi Wang ◽  
Xiu yan Li ◽  
Xiaojie Duan
Keyword(s):  
Electrical Resistance ◽  
Transient Flow ◽  
Two Phase Flow ◽  
Flow Imaging ◽  
Phase Flow ◽  
Electrical Resistance Tomography ◽  
Two Phase ◽  
Flow Process ◽  
Content Type ◽  
High Level

Purpose The purpose of this paper is to explore gas/liquid two-phase flow is widely existed in industrial fields, especially in chemical engineering. Electrical resistance tomography (ERT) is considered to be one of the most promising techniques to monitor the transient flow process because of its advantages such as fast respond speed and cross-section imaging. However, maintaining high resolution in space together with low cost is still challenging for two-phase flow imaging because of the ill-conditioning of ERT inverse problem. Design/methodology/approach In this paper, a sparse reconstruction (SR) method based on the learned dictionary has been proposed for ERT, to accurately monitor the transient flow process of gas/liquid two-phase flow in a pipeline. The high-level representation of the conductivity distributions for typical flow regimes can be extracted based on denoising the deep extreme learning machine (DDELM) model, which is used as prior information for dictionary learning. Findings The results from simulation and dynamic experiments indicate that the proposed algorithm efficiently improves the quality of reconstructed images as compared to some typical algorithms such as Landweber and SR-discrete fourier transformation/discrete cosine transformation. Furthermore, the SR-DDELM has also used to estimate the important parameters of the chemical process, a case in point is the volume flow rate. Therefore, the SR-DDELM is considered an ideal candidate for online monitor the gas/liquid two-phase flow. Originality/value This paper fulfills a novel approach to effectively monitor the gas/liquid two-phase flow in pipelines. One deep learning model and one adaptive dictionary are trained via the same prior conductivity, respectively. The model is used to extract high-level representation. The dictionary is used to represent the features of the flow process. SR and extraction of high-level representation are performed iteratively. The new method can obviously improve the monitoring accuracy and save calculation time.

Variational multi-scale finite element method for the two-phase flow of polymer melt filling process

2019 ◽  
Vol 30 (3) ◽  
pp. 1407-1426 ◽  
Author(s):  
Xuejuan Li ◽  
Ji-Huan He
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Numerical Method ◽  
Two Phase Flow ◽  
Polymer Melt ◽  
Phase Flow ◽  
Filling Process ◽  
Two Phase ◽  
Content Type ◽  
Element Method

Purpose The purpose of this paper is to develop an effective numerical algorithm for a gas-melt two-phase flow and use it to simulate a polymer melt filling process. Moreover, the suggested algorithm can deal with the moving interface and discontinuities of unknowns across the interface. Design/methodology/approach The algebraic sub-grid scales-variational multi-scale (ASGS-VMS) finite element method is used to solve the polymer melt filling process. Meanwhile, the time is discretized using the Crank–Nicolson-based split fractional step algorithm to reduce the computational time. The improved level set method is used to capture the melt front interface, and the related equations are discretized by the second-order Taylor–Galerkin scheme in space and the third-order total variation diminishing Runge–Kutta scheme in time. Findings The numerical method is validated by the benchmark problem. Moreover, the viscoelastic polymer melt filling process is investigated in a rectangular cavity. The front interface, pressure field and flow-induced stresses of polymer melt during the filling process are predicted. Overall, this paper presents a VMS method for polymer injection molding. The present numerical method is extremely suitable for two free surface problems. Originality/value For the first time ever, the ASGS-VMS finite element method is performed for the two-phase flow of polymer melt filling process, and an effective numerical method is designed to catch the moving surface.

Experimental Investigation on Flow Patterns and Frictional Pressure Drop of Downward Air-Water Two-Phase Flow in Vertical Pipes

2013 ◽  
Author(s):  
Yuqing Xue ◽  
Huixiong Li ◽  
Tianyou Sheng ◽  
Changjiang Liao
Keyword(s):  
Pressure Drop ◽  
Flow Pattern ◽  
Oil Recovery ◽  
Two Phase Flow ◽  
Flow Patterns ◽  
Phase Flow ◽  
Vertical Pipe ◽  
Two Phase Flows ◽  
Two Phase ◽  
Frictional Pressure Drop

A large amount of air need be transported into the reservoir in the deep stratum to supply oxygen to some microbes in Microbial Enhanced Oil Recovery (MEOR). Air-water two-phase flows downward along vertical pipeline during the air transportation. Base on the experiment data described in this paper, the characteristics of air-water two phase flow patterns were investigated. The flow pattern map of air-water two phase flows in the pipe with inner diameter of 65 mm was drawn, criterions of flow pattern transition were discussed, and the dynamic signals of the pressure and the differential pressure of the two phase flow were recorded to characterize the three basic flow regimes indirectly. The frictional pressure drop of downward flow in vertical pipe must not be disregarded contrast with upward two phase flow in the vertical pipe because the buoyancy must be overcame when the gas flows downward along pipe, and there would be a maximum value of frictional when the flow pattern translated from slug flow to churn flow.

A novel discontinuous Galerkin model for two-phase flow in porous media using an improved IMPES method

2016 ◽  
Vol 26 (1) ◽  
pp. 284-306 ◽  
Author(s):  
Mehdi Jamei ◽  
H Ghafouri
Keyword(s):  
Porous Media ◽  
Discontinuous Galerkin ◽  
Numerical Scheme ◽  
Two Phase Flow ◽  
Weighted Average ◽  
Computation Time ◽  
Flow In Porous Media ◽  
Phase Flow ◽  
Two Phase ◽  
Content Type

Purpose – The purpose of this paper is to present an efficient improved version of Implicit Pressure-Explicit Saturation (IMPES) method for the solution of incompressible two-phase flow model based on the discontinuous Galerkin (DG) numerical scheme. Design/methodology/approach – The governing equations, based on the wetting-phase pressure-saturation formulation, are discretized using various primal DG schemes. The authors use H(div) velocity reconstruction in Raviart-Thomas space (RT_0 and RT_1), the weighted average formulation, and the scaled penalties to improve the spatial discretization. It uses a new improved IMPES approach, by using the second-order explicit Total Variation Diminishing Runge-Kutta (TVD-RK) as temporal discretization of the saturation equation. The main purpose of this time stepping technique is to speed up computation without losing accuracy, thus to increase the efficiency of the method. Findings – Utilizing pressure internal interpolation technique in the improved IMPES scheme can reduce CPU time. Combining the TVD property with a strong multi-dimensional slope limiter namely, modified Chavent-Jaffre leads to a non-oscillatory scheme even in coarse grids and highly heterogeneous porous media. Research limitations/implications – The presented locally conservative scheme can be applied only in 2D incompressible two-phase flow modeling in non-deformable porous media. In addition, the capillary pressure discontinuity between two adjacent rock types assumed to be negligible. Practical implications – The proposed numerical scheme can be efficiently used to model the incompressible two-phase flow in secondary recovery of petroleum reservoirs and tracing immiscible contamination in aquifers. Originality/value – The paper describes a novel version of the DG two-phase flow which illustrates the effects of improvements in special discretization. Also the new improved IMPES approach used reduces the computation time. The non-oscillatory scheme is an efficient algorithm as it maintains accuracy and saves computation time.

Influence of selected parameters on phenomena of two-phase flow and heat exchange in TSL furnace – numerical investigation

2017 ◽  
Vol 27 (12) ◽  
pp. 2799-2815
Author(s):  
Ewa Kolczyk ◽  
Zdzisław Miczkowski ◽  
Józef Czernecki
Keyword(s):  
Numerical Simulation ◽  
Heat Exchange ◽  
Liquid Slag ◽  
Gas Flow ◽  
Two Phase Flow ◽  
New Technology ◽  
Phase Flow ◽  
Two Phase ◽  
Content Type ◽  
Submerged Lance

Purpose The purpose of this study is application of a numerical simulation for determination of the influence of geometric parameters of a furnace and hydrodynamics of the gas introduced by a vertical submerged lance on the process of feed mixing and temperature distribution. Design/methodology/approach A numerical simulation with Phoenics software was applied for modeling of liquid phase movement and heat exchange between the gas supplied through a lance and the slag feed in a top submerged lance (TSL) furnace. The simulation of a two-phase flow of a slag–gas mixture based on the inter phase slip algorithm module was conducted. The influence of selected parameters, such as depth of lance submergence, gas flow rate and change of furnace geometry, on the phenomena of movement was studied. Findings Growth of dynamics of mixing with the depth of lance submergence and with increase of gas velocity in the lance was observed. Formation of a recirculation zone in the liquid slag was registered. Movement of the slag caused by the gas flow brought homogenization of the temperature field. Originality/value The study applied the simulation of a two-phase flow in the liquid slag–gas system in steady state, taking into account heat transfer between phases. It provides possibilities for optimization and selection of process parameters within the scope of the developed new technology using a TSL furnace.

Correlations of the Holdup and the Frictional Pressure Drop in Air-Water Two-Phase Flow in a Flat Capillary Rectangular Channel

2004 ◽  
Author(s):  
Hideo Ide ◽  
Tohru Fukano
Keyword(s):  
Pressure Drop ◽  
Aspect Ratio ◽  
Two Phase Flow ◽  
Rectangular Channel ◽  
Flow Characteristics ◽  
Phase Flow ◽  
Two Phase Flows ◽  
Two Phase ◽  
Frictional Pressure Drop ◽  
Flow Phenomena

Both vertical upward and horizontal gas-liquid two-phase flows in a flat capillary rectangular channel were studied to clarify the flow phenomena, the holdup and the frictional pressure drop. The dimension of the channel used was 9.9 mm × 1.1 mm. The orientations of the channel were with the wide side vertical and the wide side horizontal. The differences between the flow characteristics in such orientations were investigated. New correlations of holdup and frictional pressure drop for flat capillary channels are proposed, in which the effect of aspect ratio has been taken into consideration.

Sign in / Sign up

Export Citation Format

Share Document