Determination of the Dynamic Characteristics of a Hydraulic Reservoir for its Air Release Efficiency Using Multiphase CFD Model

2018 ◽  
Author(s):  
Rahelehsadat Mostafavi ◽  
Dominic Tiffin ◽  
Katharina Schmitz
Keyword(s):  
Hydraulic Systems ◽  
Cfd Model ◽  
Lagrangian Particle Tracking ◽  
Flow Conditions ◽  
Lagrangian Particle ◽  
Air Content ◽  
Oil Flow ◽  
Key Variables ◽  
Multiphase Cfd

Undissolved air in oil causes various problems for hydraulic systems and strongly decreases the efficiency of the system. In this respect, the hydraulic reservoir as the only component that performs the function of releasing the accumulated air from the system is relevant. In recent years, the air release efficiency in hydraulic reservoirs has been studied both experimentally and in simulation. However, in none of the according studies dynamically changing flow conditions have been considered. In this paper, the air release behaviour of a hydraulic reservoir is investigated through simulation, considering the dynamics of the system. The developed multiphase CFD model utilizes the open-source CFD tool, OpenFOAM®, based on a Lagrangian Particle Tracking (LPT) within an Eulerian phase. The simulations have been conducted varying the key variables such as oil flow rate and air load at the inlet of the reservoir and yield the air content at the outlet.

scholarly journals CFD modelling of the condensation, evaporation, coagulation and crystallization processes in the cooling tower emissions

2021 ◽  
Vol 2088 (1) ◽  
pp. 012013
Author(s):  
M I Ershov ◽  
V G Tuponogov ◽  
N A Abaimov ◽  
M A Gorsky
Keyword(s):  
Single Phase ◽  
Cooling Tower ◽  
Cfd Model ◽  
Lagrangian Particle Tracking ◽  
Lagrangian Particle ◽  
Cfd Modelling ◽  
Ansys Fluent ◽  
Flow Modelling ◽  
Fluent Software ◽  
Modelling Approach

Abstract The aim of the paper is to develop the CFD model for the environmental impact assessment of the cooling tower. The methods applied for this problem are the single-phase turbulent multispecies flow modelling with the DPM Lagrangian particle tracking. The simulations have been carried out in the steady state SIMPLE solver using the ANSYS Fluent software. User Defined Functions have been defined to enhance the accuracy and versatility of the modelling approach in terms of turbulence, fog formation, evaporation, coagulation and crystallization modelling. The Chalk Point cooling tower experiment, laboratory tests with freezing droplets and analytical correlations are used to verify the customized parts of the new CFD model. The arbitrary small-town geometry is used to demonstrate the simulation capabilities of the fog and drift deposition as well as the temperature and relative humidity values near ground and buildings. The results indicate that the new CFD model is able to predict the cooling tower plume parameters, icing and salt contamination risks as well as drift deposition.

scholarly journals First challenge on Lagrangian Particle Tracking and Data Assimilation: datasets description and planned evolution to an open online benchmark

2021 ◽  
Vol 1 (1) ◽  
Author(s):  
Benjamin Leclaire ◽  
Ivan Mary ◽  
Cédric Liauzun ◽  
Stéphanie Péron ◽  
Andrea Sciacchitano ◽  
...  
Keyword(s):  
Data Assimilation ◽  
Particle Tracking ◽  
Measurement Techniques ◽  
Three Dimensional ◽  
Fluid Flows ◽  
Lagrangian Particle Tracking ◽  
Lagrangian Particle ◽  
Pressure Fields ◽  
Significant Research

In the last decade, Lagrangian Particle Tracking (LPT) has emerged as one of the leading measurement techniques for the quantitative determination of fluid flows in three-dimensional domains (see e.g. Schanz et al., 2016), due to its accuracy in reconstructing particles velocities and material accelerations. Due to the scattered nature of the obtained result, at the particles positions only, significant research efforts have also been placed in the development of dedicated Data Assimilation (DA) techniques, aiming at finally reconstructing full 3D velocity and pressure fields on regular Cartesian grids (see, e.g., Schneiders et al. 2016).

Solid Particle Erosion Downstream of an Orifice

2014 ◽  
Vol 137 (2) ◽  
Author(s):  
M. A. Nemitallah ◽  
R. Ben-Mansour ◽  
M. A. Habib ◽  
W. H. Ahmed ◽  
I. H. Toor ◽  
...  
Keyword(s):  
Solid Particle ◽  
Strong Dependence ◽  
Computational Grid ◽  
Solid Particle Erosion ◽  
Chemical Processing ◽  
Lagrangian Particle Tracking ◽  
Particle Erosion ◽  
Lagrangian Particle ◽  
Fully Developed Turbulent Flow

The paper deals with solid particle erosion downstream of a sharp-edged orifice commonly found in many chemical processing industries. The orifice is installed in a pipe that is long enough to ensure fully developed turbulent flow in both upstream and downstream directions. Both the k-ε model and the Lagrangian particle-tracking technique were used for predicting solid particle trajectories. Gambit 2.2 was used to construct the computational grid and the commercial Fluent 12.1 code was used to perform the calculations. The available erosion correlations were used for determination of erosion characteristics considering carbon steel and aluminum pipes. The investigation was carried out for a flow restricting orifice of fixed geometry and pipe flow velocities in the range 1–4 m/s using solid particle of diameters 50–500 μm. The results indicated two critical erosion regions downstream of the orifice: the first is in the immediate neighborhood of the orifice plate and the second is in the flow reattachment zone. The results showed also a strong dependence of erosion on both particle size and flow velocity.

Diagnostics of the location of damage to tubing oil well pipes

2019 ◽  
Vol 5 (4) ◽  
pp. 115-128
Author(s):  
Timur A. Ishmuratov ◽  
Rif G. Sultanov ◽  
Milyausha N. Khusnutdinova
Keyword(s):  
Fluid Motion ◽  
Oil Well ◽  
General Belief ◽  
Oil Flow ◽  
Specialized Equipment ◽  
Improving Accuracy ◽  
Analytical Expressions ◽  
Technical Measures ◽  
Quick Determination

The study is devoted to the mathematical description of the process of oil outflow in places of leakage of the tubing string, which allows a computer to locate a leakage in the tubing. The authors propose methodology for identifying defects in the tubing and determining the location of the leak. The uniqueness of this methodology lies in quick determination of the place of leakage without the use of specialists, sophisticated and specialized equipment. Mathematical modeling of oil flow in the tubing requires the apparatus of continuum mechanics. It is a general belief that the movement of oil in the pipe flows at low speeds due to its outflow from the hole. Using the general equations of mass and energy balance, the authors have obtained differential equations of fluid motion in a vertical pipe in the process of its outflow from the tubing and in the process of injection. Analytical expressions are the solution to these equations, as they can help in estimating the degree of damage and its location, as well as the feasibility of its eliminating. The results show that an increase in the leakage and injection times leads to improving accuracy of locating damage. Thus, when conducting various geological and technical measures (GTM) at the well, it is possible to assess the presence of leakage and its intensity when deciding on the repair of tubing.

scholarly journals Box-Behnken Assisted Validation and Optimization of an RP-HPLC Method for Simultaneous Determination of Domperidone and Lansoprazole

Separations ◽  
2021 ◽  
Vol 8 (1) ◽  
pp. 5
Author(s):  
Mohd Afzal ◽  
Mohd. Muddassir ◽  
Abdullah Alarifi ◽  
Mohammed Tahir Ansari
Keyword(s):  
Flow Rate ◽  
Mobile Phase ◽  
Limit Of Detection ◽  
Hplc Method ◽  
Box Behnken Design ◽  
Rp Hplc ◽  
System Suitability ◽  
Method Optimization ◽  
Key Variables

A highly specific, accurate, and simple RP-HPLC technique was developed for the real-time quantification of domperidone (DOMP) and lansoprazole (LANS) in commercial formulations. Chromatographic studies were performed using a Luna C8(2), 5 μm, 100Å, column (250 × 4.6 mm, Phenomenex) with a mobile phase composed of acetonitrile/2 mM ammonium acetate (51:49 v/v), pH 6.7. The flow rate was 1 mL·min−1 with UV detection at 289 nm. Linearity was observed within the range of 4–36 µg·mL−1 for domperidone and 2–18 µg·mL−1 for lansoprazole. Method optimization was achieved using Box-Behnken design software, in which three key variables were examined, namely, the flow rate (A), the composition of the mobile phase (B), and the pH (C). The retention time (Y1 and Y3) and the peak area (Y2 and Y4) were taken as the response parameters. We observed that slight alterations in the mobile phase and the flow rate influenced the outcome, whereas the pH exerted no effect. Method validation featured various ICH parameters including linearity, limit of detection (LOD), accuracy, precision, ruggedness, robustness, stability, and system suitability. This method is potentially useful for the analysis of commercial formulations and laboratory preparations.

scholarly journals New Equation for Predicting Pipe Friction Coefficients Using the Statistical Based Entropy Concepts

Entropy ◽  
2021 ◽  
Vol 23 (5) ◽  
pp. 611
Author(s):  
Yeon-Woong Choe ◽  
Sang-Bo Sim ◽  
Yeon-Moon Choo
Keyword(s):  
Friction Coefficient ◽  
Accurate Determination ◽  
Mean Velocity ◽  
Friction Coefficients ◽  
Flow Discharge ◽  
Comparison Results ◽  
Flow Loss ◽  
Key Variables ◽  
New Equation

In general, this new equation is significant for designing and operating a pipeline to predict flow discharge. In order to predict the flow discharge, accurate determination of the flow loss due to pipe friction is very important. However, existing pipe friction coefficient equations have difficulties in obtaining key variables or those only applicable to pipes with specific conditions. Thus, this study develops a new equation for predicting pipe friction coefficients using statistically based entropy concepts, which are currently being used in various fields. The parameters in the proposed equation can be easily obtained and are easy to estimate. Existing formulas for calculating pipe friction coefficient requires the friction head loss and Reynolds number. Unlike existing formulas, the proposed equation only requires pipe specifications, entropy value and average velocity. The developed equation can predict the friction coefficient by using the well-known entropy, the mean velocity and the pipe specifications. The comparison results with the Nikuradse’s experimental data show that the R2 and RMSE values were 0.998 and 0.000366 in smooth pipe, and 0.979 to 0.994 or 0.000399 to 0.000436 in rough pipe, and the discrepancy ratio analysis results show that the accuracy of both results in smooth and rough pipes is very close to zero. The proposed equation will enable the easier estimation of flow rates.

scholarly journals 3D Lagrangian particle tracking of a subsonic jet using multi-pulse Shake-The-Box

2021 ◽  
Vol 123 ◽  
pp. 110346
Author(s):  
Peter Manovski ◽  
Matteo Novara ◽  
Nagendra Karthik Depuru Mohan ◽  
Reinhard Geisler ◽  
Daniel Schanz ◽  
...  
Keyword(s):  
Particle Tracking ◽  
Lagrangian Particle Tracking ◽  
Lagrangian Particle ◽  
Subsonic Jet
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