scholarly journals Fully turbulent discrete adjoint solver for non-ideal compressible flow applications

2017 ◽  
Vol 1 ◽  
pp. Z1FVOI ◽  
Author(s):  
Salvatore Vitale ◽  
Tim A. Albring ◽  
Matteo Pini ◽  
Nicolas R. Gauger ◽  
Piero Colonna
Keyword(s):  
Oil And Gas ◽  
Automatic Differentiation ◽  
Fluid Dynamic ◽  
Dynamic Performance ◽  
Oil And Gas Industry ◽  
Ideal Gas ◽  
Working Fluid ◽  
Viscous Effects ◽  
Two Phase ◽  
Flow Equations

Abstract Non-Ideal Compressible Fluid-Dynamics (NICFD) has recently been established as a sector of fluid mechanics dealing with the flows of dense vapors, supercritical fluids, and two-phase fluids, whose properties significantly depart from those of the ideal gas. The flow through an Organic Rankine Cycle (ORC) turbine is an exemplary application, as stators often operate in the supersonic and transonic regime, and are affected by NICFD effects. Other applications are turbomachinery using supercritical CO2 as working fluid or other fluids typical of the oil and gas industry, and components of air conditioning and refrigeration systems. Due to the comparably lower level of experience in the design of this fluid machinery, and the lack of experimental information on NICFD flows, the design of the main components of these processes (i.e., turbomachinery and nozzles) may benefit from adjoint-based automated fluid-dynamic shape optimization. Hence, this work is related to the development and testing of a fully-turbulent adjoint method capable of treating NICFD flows. The method was implemented within the SU2 open-source software infrastructure. The adjoint solver was obtained by linearizing the discretized flow equations and the fluid thermodynamic models by means of advanced Automatic Differentiation (AD) techniques. The new adjoint solver was tested on exemplary turbomachinery cases. Results demonstrate the method effectiveness in improving simulated fluid-dynamic performance, and underline the importance of accurately modeling non-ideal thermodynamic and viscous effects when optimizing internal flows influenced by NICFD phenomena.

scholarly journals Effects of Fluid Viscosity and Two-Phase Flow on Performance of ESP

Energies ◽  
2020 ◽  
Vol 13 (20) ◽  
pp. 5486
Author(s):  
Peng Liu ◽  
Yumo Wang ◽  
Feng Yan ◽  
Chaofei Nie ◽  
Xin Ouyang ◽  
...  
Keyword(s):  
Oil And Gas ◽  
Two Phase Flow ◽  
Economic Cost ◽  
Oil And Gas Industry ◽  
Fluid Viscosity ◽  
Phase Flow ◽  
Viscous Effects ◽  
Two Phase ◽  
Gas Industry ◽  
Efficient Operation

Electric submersible pumps (ESPs) are widely used in the oil and gas industry for crude-oil lifting, especially in subsea oil fields or underground storage caverns. The failure of ESPs causes a large economic cost mainly attributed to a break in production continuity, as the ESP cannot be easily replaced. Therefore, the assurance of safe and efficient operation of ESPs has attracted high attention in recent years, although the problem still remains challenging given the complexity of carrying fluid and the mechanical structure of the ESP. In this article, we systematically review both the high-impact, classic contributions and the most up-to-date, current opinions in experimental and numerical advances of viscous effects and two-phase flow in ESPs. We specifically focus on the applications in the oil and gas industry and point out a few current challenges in the operation of ESPs. We aim to guide the audience which is new to the area of ESPs to the correct articles related to their interests, including classic work and recent advances.

scholarly journals Large Eddy Simulations of Strongly Non-Ideal Compressible Flows through a Transonic Cascade

Energies ◽  
2021 ◽  
Vol 14 (3) ◽  
pp. 772
Author(s):  
Jean-Christophe Hoarau ◽  
Paola Cinnella ◽  
Xavier Gloerfelt
Keyword(s):  
Compressible Flows ◽  
Flow Behavior ◽  
Pressure Ratio ◽  
Organic Rankine Cycle ◽  
Ideal Gas ◽  
Operating Conditions ◽  
Large Eddy Simulations ◽  
Working Fluid ◽  
Viscous Effects ◽  
Large Eddy

Transonic flows of a molecularly complex organic fluid through a stator cascade were investigated by means of large eddy simulations (LESs). The selected configuration was considered as representative of the high-pressure stages of high-temperature Organic Rankine Cycle (ORC) axial turbines, which may exhibit significant non-ideal gas effects. A heavy fluorocarbon, perhydrophenanthrene (PP11), was selected as the working fluid to exacerbate deviations from the ideal flow behavior. The LESs were carried out at various operating conditions (pressure ratio and total conditions at inlet), and their influence on compressibility and viscous effects is discussed. The complex thermodynamic behavior of the fluid generates highly non-ideal shock systems at the blade trailing edge. These are shown to undergo complex interactions with the transitional viscous boundary layers and wakes, with an impact on the loss mechanisms and predicted loss coefficients compared to lower-fidelity models relying on the Reynolds-averaged Navier–Stokes (RANS) equations.

Experiment and Dynamic Simulation of PIG Motion during Pigging Operation in a Slope Pipeline

2018 ◽  
Vol 16 (9) ◽  
Author(s):  
Jun Zhou ◽  
Tao Deng ◽  
Guangchuan Liang ◽  
Jinghong Peng ◽  
Tian Meng ◽  
...  
Keyword(s):  
Oil And Gas ◽  
Water Pressure ◽  
Oil And Gas Industry ◽  
Unsteady Motion ◽  
Stable Operation ◽  
Two Phase ◽  
Transient Model ◽  
Water Pressure Test ◽  
Pressure Test ◽  
Hydraulic Pulse

Abstract Pigging techniques are widely used in the oil and gas industry. The unsteady motion of the PIG in an undulating pipe section during the pigging process after a water pressure test affects the stable operation of the pipeline and also causes a pipe rupture accident in serious cases. First, an experimental study was conducted to investigate the pigging process of air–water two phase pipe flows, and the PIG reverse movement and hydraulic pulse phenomenon were observed. Subsequently, a hydraulic transient model of the pigging process after a water pressure test was established in a dual-grid system. The model combined mass and motion equations of gas and liquid and PIG dynamic equations, considered three types of PIG motion states, namely positive movement, reverse movement and still, and used the method of characteristics to solve the equations. The model exhibits the ability for PIG tracing and hydraulic pulse prediction. It can be used to obtain the position and speed of the PIG. Finally, the field data and simulation results were compared, and the results indicated that they are essentially identical. This verified the accuracy of the model that is established in this study and the reliability of computed results and provided a reliable and effective theoretical basis for the development of field pigging plans.

scholarly journals Multiphase gas-flow model of an electrical submersible pump

2018 ◽  
Vol 73 ◽  
pp. 29
Author(s):  
Diana Marcela Martinez Ricardo ◽  
German Efrain Castañeda Jiménez ◽  
Janito Vaqueiro Ferreira ◽  
Pablo Siqueira Meirelles
Keyword(s):  
Gas Flow ◽  
Oil And Gas ◽  
Learning Algorithm ◽  
Estimation Error ◽  
Oil And Gas Industry ◽  
Support Vector ◽  
System Response ◽  
Submersible Pump ◽  
Two Phase ◽  
Electrical Submersible Pump

Various artificial lifting systems are used in the oil and gas industry. An example is the Electrical Submersible Pump (ESP). When the gas flow is high, ESPs usually fail prematurely because of a lack of information about the two-phase flow during pumping operations. Here, we develop models to estimate the gas flow in a two-phase mixture being pumped through an ESP. Using these models and experimental system response data, the pump operating point can be controlled. The models are based on nonparametric identification using a support vector machine learning algorithm. The learning machine’s hidden parameters are determined with a genetic algorithm. The results obtained with each model are validated and compared in terms of estimation error. The models are able to successfully identify the gas flow in the liquid-gas mixture transported by an ESP.

Computational and Experimental Investigation of the Vertical Flash Tank Separator Part 1: Effect of Parameters on Separation Efficiency

2019 ◽  
Vol 27 (01) ◽  
pp. 1950005 ◽  
Author(s):  
Raid Ahmed Mahmood ◽  
David Buttsworth ◽  
Ray Malpress
Keyword(s):  
Separation Efficiency ◽  
Fluid Dynamic ◽  
Effective Area ◽  
Working Fluid ◽  
Cfd Simulations ◽  
Liquid Separation ◽  
Two Phase ◽  
Flash Tank ◽  
Tank Design ◽  
The Heat Transfer Coefficient

The flash tank separator is one of the most important components that can be used to improve the performance of a refrigeration cycle by separating the liquid from the gas–liquid two-phase flow and providing the evaporator with only liquid refrigerant. This technique increases the effective area and enhances the heat transfer coefficient in the evaporator. To optimize the size of the vertical flash tank separator for obtaining high separation efficiency, the effect of the size of the vertical flash tank separator needs to be considered. This paper investigates the effect of the size on the liquid separation efficiency of the vertical flash tank separator. This paper also assesses the usefulness of Computational Fluid Dynamic (CFD) in flash tank design, and this is achieved through experiments and simulations on a range of relevant configurations using water as the working fluid. The results revealed that the size has a significant effect on the liquid separation efficiency, as the highest value was achieved by the largest size (VFT-V5). The CFD simulations give a good agreement with the experiments; all the simulations underestimated the liquid separation efficiency by approximately 0.02 over the range of conditions tested.

scholarly journals Comparative Study of CFD and LedaFlow Models for Riser-Induced Slug Flow

Energies ◽  
2020 ◽  
Vol 13 (14) ◽  
pp. 3733
Author(s):  
Rasmus Thy Jørgensen ◽  
Gunvor Rossen Tonnesen ◽  
Matthias Mandø ◽  
Simon Pedersen
Keyword(s):  
Slug Flow ◽  
Oil And Gas ◽  
Cfd Simulation ◽  
Numerical Models ◽  
Oil And Gas Industry ◽  
Test Facility ◽  
Cfd Model ◽  
Two Phase ◽  
Transient Model ◽  
Vof Model

The goal of this study is to compare mainstream Computational Fluid Dynamics (CFD) with the widely used 1D transient model LedaFlow in their ability to predict riser induced slug flow and to determine if it is relevant for the offshore oil and gas industry to consider making the switch from LedaFlow to CFD. Presently, the industry use relatively simple 1D-models, such as LedaFlow, to predict flow patterns in pipelines. The reduction in cost of computational power in recent years have made it relevant to compare the performance of these codes with high fidelity CFD simulations. A laboratory test facility was used to obtain data for pressure and mass flow rates for the two-phase flow of air and water. A benchmark case of slug flow served for evaluation of the numerical models. A 3D unsteady CFD simulation was performed based on Reynolds-Averaged Navier-Stokes (RANS) formulation and the Volume of Fluid (VOF) model using the open-source CFD code OpenFOAM. Unsteady simulations using the commercial 1D LedaFlow solver were performed using the same boundary conditions and fluid properties as the CFD simulation. Both the CFD and LedaFlow model underpredicted the experimentally determined slug frequency by 22% and 16% respectively. Both models predicted a classical blowout, in which the riser is completely evacuated of water, while only a partial evacuation of the riser was observed experimentally. The CFD model had a runtime of 57 h while the LedaFlow model had a runtime of 13 min. It can be concluded that the prediction capabilities of the CFD and LedaFlow models are similar for riser-induced slug flow while the CFD model is much more computational intensive.

DO BUSINESS ETHICS REALLY MATTER?

2003 ◽  
Vol 43 (1) ◽  
pp. 705
Author(s):  
A. Lagan
Keyword(s):  
Business Ethics ◽  
Performance Management ◽  
Oil And Gas ◽  
Oil And Gas Industry ◽  
Business Case ◽  
Organisational Performance ◽  
Ethical Perspective ◽  
Two Phase ◽  
Ethical Imperative ◽  
New Business

There are few people today who would dare to say that business and ethics are incompatible forces. This was not the case so very long ago. Despite this shift, the recent spate of spectacular business collapses would seem to suggest that there is still a lag between the values being espoused by today’s business leaders, and the resources allocated to ensuring the ethical imperative is embedded in day-to-day decision-making.This paper seeks to present an overview of where the business ethics debate sits today and how this relates to the current state of ethical play in the oil and gas industry. It reviews the major forces pushing ethics up the corporate agenda and seeks to build the business case for why attention to business ethics will improve overall organisational performance. It does this by reviewing the new business philosophies of sustainability and corporate social responsibility (CSR) and argues that these new business doctrines can be seen as essentially applied ethical practices and present the greatest opportunity to date for embedding the ethical imperative in organisational life.The author argues that historically it has been the oil and gas industries that have been the first to recognise the interdependence of business ethics and organisational performance and that it is these industries have now moved into stage two phase of sustainability development where they are focussing their efforts on embedding the ethical perspective into their day-to-day performance management systems.

Numerical Analysis of Elbow Erosion Mitigation Using Swirl Pipes in Gas-Particle Two-Phase Flows

2021 ◽  
Author(s):  
A. Farokhipour ◽  
Z. Mansoori ◽  
M. Saffar-Avval ◽  
G. Ahmadi
Keyword(s):  
Erosion Rate ◽  
Oil And Gas ◽  
Oil And Gas Industry ◽  
Swirl Flow ◽  
Sand Particle ◽  
Two Phase ◽  
Simple Method ◽  
Gas Industry ◽  
Sand Erosion ◽  
Erosion Mitigation

Abstract In the oil and gas industry, sand particle erosion damage to elbows is a common problem. The ability to predict erosion patterns is of great importance for sizing lines, analyzing failures, and limiting production rates. Computational fluid dynamics (CFD) can be utilized to study the erosion behavior and mitigate the erosion problem for safety purposes and greater equipment longevity. In order to alleviate the adverse results of sand erosion in elbows, the current study investigated the potential of the geometrically induced swirl flow generated from flow passing through a four-lobed twisted pipe upstream of an elbow. To this end, first, the airflow in a standard elbow equipped with different swirl pipes was simulated using the SIMPLE method, then an Eulerian-Lagrangian approach was employed to track the particles, and finally, the erosion rate was computed. The simulation results indicated that the elbow’s maximum erosion rate with twisted pipes placed upstream of the elbow is lower than the one obtained for the standard pipe. In addition, as the twisted pipe position gets closer to the bend, the erosion rate further reduces. Thus, swirling flows provide a promising prospect as a mechanism to control the erosion rate in elbows.

Design and analysis of a mathematical model of the motion of a heterogeneous fluid in a well

2021 ◽  
Author(s):  
N.P. Petrov ◽  
S.N. Petrova ◽  
N. V. Korzhavina ◽  
E. V. Lisovsky
Keyword(s):  
Continuum Mechanics ◽  
Differential Calculus ◽  
Oil And Gas ◽  
Fluid Motion ◽  
Oil And Gas Industry ◽  
Environmental Safety ◽  
Systems Of Equations ◽  
Two Phase ◽  
Gas Industry ◽  
Multiphase Fluid

The development of methods for modeling the motion of fluid in a well is an urgent area of both theoretical and applied interest. In mathematical modeling of real processes of fluid motion, it is possible to use a description using continuous distributions and use a well-developed apparatus of continuum mechanics and differential calculus. The purpose of the work is to synthesize and analyze a model of the motion of a heterogeneous fluid in a well based on the methods of continuum mechanics and differential calculus. The issues of constructing and studying models of the motion of a multiphase fluid in a well are considered. Systems of equations of conservation of phase masses, momentum and energy of a two-phase mixture are studied. The approach to the search for the optimal pressure of liquid supply to the well and to the estimation of the velocity distribution of liquid and particles is described. The results can find applications in modeling processes related to fluid movement, as well as in the development of technologies in the oil and gas industry, as well as technologies aimed at ensuring environmental safety.

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