A Gas Separation Model for a Downhole Gravitational Separator

SPE Journal ◽  
2021 ◽  
pp. 1-14
Author(s):  
P. J. Miranda-Lugo ◽  
L. Enrique Ortiz-Vidal ◽  
O. M. H. Rodriguez
Keyword(s):  
Energy Dissipation ◽  
Gas Separation ◽  
Void Fraction ◽  
High Speed ◽  
Annular Channel ◽  
Detection Algorithm ◽  
Surface Flow ◽  
Free Gas ◽  
Gas Entrainment ◽  
Starting Point

Summary Pumping systems reduce their efficiency and lifetime when working with free gas at the pump inlet. Downhole gas separators are usually installed upstream of the pump in oil production wells to avoid free gas, but they cannot handle high void fraction. Studies on the so-calledinverted-shroud gravitational separator indicate that it is possible to achieve gas separation efficiencies (GSEs) higher than 97%, even in the presence of very high void fraction. Gas separation inside this kind of separator works in two stages. The most critical stage is related to gas entrainment caused by a plunging free-surface flow in an annular channel formed by the production tubing and the separator itself, where strong kinetic energy dissipation takes place. Studies regarding this phenomenon in inverted-shroud separators are scanty. In this study, we present a semianalytical model supported by an empirical turbulent energy-dissipation correlation. The proposed correlation is based on dimensional analysis. New experimental data of the statistical distributions of bubble diameters during the gas entrainment process are presented. We measured bubbles diameters using a high-speed video camera and an edge detection algorithm. Data of both bubble diameters and GSE were used to adjust and validate the proposed model. The model establishes a transition boundary that separates a region of total gas separation (TGS) from a region of partial gas separation (PGS). In other words, it provides the operating envelope of the separator. The results can be used as a starting point for the design of inverted-shroud separators for field applications.

scholarly journals Part-optimized forming by spatially distributed vaporizing foil actuators

2021 ◽  
Author(s):  
Marlon Hahn ◽  
A. Erman Tekkaya
Keyword(s):  
Process Design ◽  
High Speed ◽  
Specific Impulse ◽  
Design Procedure ◽  
Mathematical Optimization ◽  
Starting Point ◽  
Spatially Distributed ◽  
Lower Tool ◽  
A Minor ◽  
Charging Energy

AbstractElectrically vaporizing foil actuators are employed as an innovative high speed sheet metal forming technology, which has the potential to lower tool costs. To reduce experimental try-outs, a predictive physics-based process design procedure is developed for the first time. It consists of a mathematical optimization utilizing numerical forming simulations followed by analytical computations for the forming-impulse generation through the rapid Joule heating of the foils. The proposed method is demonstrated for an exemplary steel sheet part. The resulting process design provides a part-specific impulse distribution, corresponding parallel actuator geometries, and the pulse generator’s charging energy, so that all process parameters are available before the first experiment. The experimental validation is then performed for the example part. Formed parts indicate that the introduced method yields a good starting point for actual testing, as it only requires adjustments in the form of a minor charging energy augmentation. This was expectable due to the conservative nature of the underlying modeling. The part geometry obtained with the most suitable charging energy is finally compared to the target geometry.

scholarly journals High-Speed Target Detection Algorithm Based on Sparse Fourier Transform

IEEE Access ◽  
2018 ◽  
Vol 6 ◽  
pp. 37828-37836 ◽  
Author(s):  
Cunsuo Pang ◽  
Shengheng Liu ◽  
Yan Han
Keyword(s):  
Fourier Transform ◽  
Target Detection ◽  
High Speed ◽  
Detection Algorithm

Based on the CO2 Gas Shielded Welding Molten Pool Image Edge Detection Algorithm

2013 ◽  
Vol 437 ◽  
pp. 840-844 ◽  
Author(s):  
Xiao Gang Liu ◽  
Bing Zhao
Keyword(s):  
Edge Detection ◽  
Molten Pool ◽  
High Speed ◽  
Vision System ◽  
Detection Algorithm ◽  
Pass Filter ◽  
Low Pass Filter ◽  
Low Pass ◽  
Defect Recognition ◽  
Pool Image

This paper use the passive vision system through high-speed camera collects molten pool images; and then according to the frequency domain characteristics of the weld pool image Butterworth low-pass filter; gradient method for image enhancement obtained after pretreatment. Research Roberts, Sobel, Prewitt, Log, Zerocross, and Canny 6 both traditional differential operator edge detection processing results. Through comparison and analysis of choosing threshold for [0.1, 0. Canny operator can get the ideal molten pool edge character, for subsequent welding molten pool defect recognition provides favorable conditions.

scholarly journals Bubble Dynamics in a Two-Phase Bubbly Mixture

2010 ◽  
Author(s):  
Arvind Jayaprakash ◽  
Sowmitra Singh ◽  
Georges Chahine
Keyword(s):  
Void Fraction ◽  
High Speed ◽  
Bubble Dynamics ◽  
Bubble Radius ◽  
Discharge Voltage ◽  
Large Bubble ◽  
Water Mixture ◽  
Two Phase ◽  
Mixture Density ◽  
Bubbly Medium

The dynamics of a primary relatively large bubble in a water mixture including very fine bubbles is investigated experimentally and the results are provided to several parallel on-going analytical and numerical approaches. The main/primary bubble is produced by an underwater spark discharge from two concentric electrodes placed in the bubbly medium, which is generated using electrolysis. A grid of thin perpendicular wires is used to generate bubble distributions of varying intensities. The size of the main bubble is controlled by the discharge voltage, the capacitors size, and the pressure imposed in the container. The size and concentration of the fine bubbles can be controlled by the electrolysis voltage, the length, diameter, and type of the wires, and also by the pressure imposed in the container. This enables parametric study of the factors controlling the dynamics of the primary bubble and development of relationships between the bubble characteristic quantities such as maximum bubble radius and bubble period and the characteristics of the surrounding two-phase medium: micro bubble sizes and void fraction. The dynamics of the main bubble and the mixture is observed using high speed video photography. The void fraction/density of the bubbly mixture in the fluid domain is measured as a function of time and space using image analysis of the high speed movies. The interaction between the primary bubble and the bubbly medium is analyzed using both field pressure measurements and high-speed videography. Parameters such as the primary bubble energy and the bubble mixture density (void fraction) are varied, and their effects studied. The experimental data is then compared to simple compressible equations employed for spherical bubbles including a modified Gilmore Equation. Suggestions for improvement of the modeling are then presented.

Lane Detection Algorithm Based on Genetic Algorithm and its Parallel Computing Realization

2012 ◽  
Vol 479-481 ◽  
pp. 65-70
Author(s):  
Xiao Hui Zhang ◽  
Liu Qing ◽  
Mu Li
Keyword(s):  
Genetic Algorithm ◽  
Data Transmission ◽  
High Speed ◽  
High Performance ◽  
Large Data ◽  
Detection Algorithm ◽  
Lane Detection ◽  
The Road ◽  
Time Problem ◽  
High Speed Data

Based on the target detection of alignment template, the paper designs a lane alignment template by using correlation matching method, and combines with genetic algorithm for template stochastic matching and optimization to realize the lane detection. In order to solve the real-time problem of lane detection algorithm based on genetic algorithm, this paper uses the high performance multi-core DSP chip TMS320C6474 as the core, combines with high-speed data transmission technology of Rapid10, realizes the hardware parallel processing of the lane detection algorithm. By Rapid10 bus, the data transmission speed between the DSP and the DSP can reach 3.125Gbps, it basically realizes transmission without delay, and thereby solves the high speed transmission of the large data quantity between processor. The experimental results show that, no matter the calculated lane line, or the running time is better than the single DSP and PC at the parallel C6474 platform. In addition, the road detection is accurate and reliable, and it has good robustness.

Structural Fire Integrity Testing of Lightweight Structures

2016 ◽  
Author(s):  
Michael Rahm ◽  
Franz Evegren
Keyword(s):  
Safety Factor ◽  
Fire Resistance ◽  
High Speed ◽  
Time To Failure ◽  
Test Procedures ◽  
Structural Fire ◽  
Lightweight Structures ◽  
Applied Loading ◽  
Frp Composite ◽  
Starting Point

To reduce environmental impact and to manage weight in shipping and offshore, lightweight structures are becoming increasingly important. A critical issue for loadbearing structures is their structural fire integrity. It is generally evaluated by loaded furnace fire resistance tests based on ISO 834. As part of the EU project BESST, a series of such tests were performed with typical lightweight fiber reinforced polymer (FRP) composite sandwich structures. The purpose was to determine whether structural fire integrity is sensitive to the design load, design method and safety factor against buckling. In particular was examined whether the temperature at the interface between the exposed laminate and the core is critical for structural integrity and how it depends on the applied loading. Independence of the applied load would make performance solely a matter of heat transfer, which would significantly reduce necessary testing. The tests were carried out with starting point in an insulated sandwich panel system, certified as a 60 minute Fire Resisting Division (FRD-60) for high-speed craft in accordance with the Fire Test Procedures (FTP) Code. The structure consisted of 1.3 mm glass fiber reinforced polyester laminates surrounding a cross linked PVC foam core called Divinycell H80 (80 kg/m3). It was constructed for a 7 kN/m design load, which is the loading applied in the FTP Code furnace test for high-speed craft. Hence, with a conventional safety factor against buckling of 2.5 it was designed to resist a critical load of 17.4 kN/m. With basis in this design, tests were performed with structures where the thickness of the laminates or core had been altered and with adjusted safety factor against the applied loading. In addition, a test was performed with a stiffened panel. Firstly it was noted that 60 minutes of fire resistance was not achieved in most of the tests, which was a consequence of an alteration in the FTP Code test procedures. The FRD-60 structure used as starting point was certified before the 2010 edition of the FTP Code was ratified. This harmonized the test procedure between laboratories and gave a slightly tougher temperature development than when the structure was certified. However, the test results are still valid and show a small variation in the time to failure in the tests with unstiffened sandwich structures, ranging between 51 and 58.5 minutes. Changing the safety factor from 2.5 to 1.5 resulted in a relatively small decrease in time to failure of 3 minutes. The stiffened test showed that structural resistance is better achieved by use of stiffeners than by thick laminates. Furthermore, applying this as a design principle and using a safety factor of 2.5 leaves a test variation between 55 and 58.5 minutes. The temperature at the exposed laminate-core interface was quite similar in the tests at the time of failure. This excludes the test when the laminate thickness was increased as a measure for structural improvement. In conclusion, the test series shows that fire resistance bulkhead testing of insulated FRP composite panels can be simplified and does not have to be performed with varying design loads. To achieve conservative evaluation, a design concept should be evaluated by testing the panel designed for the highest applicable load level, not by testing a weak panel at 7 kN/m loading. This applies to non-stiffened solutions.

Study of BLAST Signal Detection Algorithm in LTE System

2013 ◽  
Vol 756-759 ◽  
pp. 3183-3188
Author(s):  
Tao Lei ◽  
Deng Ping He ◽  
Fang Tang Chen
Keyword(s):  
Signal Detection ◽  
High Speed ◽  
Data Communication ◽  
Detection Algorithm ◽  
Detection Performance ◽  
Detection Algorithms ◽  
High Speed Data ◽  
Simulation Results ◽  
Better Than

BLAST can achieve high speed data communication. Its signal detection directly affects performance of BLAST receiver. This paper introduced several signal detection algorithmsZF algorithm, MMSE algorithm, ZF-SIC algorithm and MMSE-SIC algorithm. The simulation results show that the traditional ZF algorithm has the worst performance, the traditional MMSE algorithm and the ZF-SIC algorithm is similar, but with the increase of the SNR, the performance of ZF-SIC algorithm is better than MMSE algorithm. MMSE-SIC algorithm has the best detection performance in these detection algorithms.

Organization and Self-Assembly Away from Equilibrium: Toward Thermodynamic Design Principles

2021 ◽  
Vol 12 (1) ◽  
pp. 273-290
Author(s):  
Michael Nguyen ◽  
Yuqing Qiu ◽  
Suriyanarayanan Vaikuntanathan
Keyword(s):  
Energy Dissipation ◽  
Self Assembly ◽  
Biological Systems ◽  
Design Principles ◽  
Nonequilibrium Process ◽  
Nanoscale Materials ◽  
Stochastic Thermodynamics ◽  
Synthetic Materials ◽  
Starting Point

Studies of biological systems and materials, together with recent experimental and theoretical advances in colloidal and nanoscale materials, have shown how nonequilibrium forcing can be used to modulate organization in many novel ways. In this review, we focus on how an accounting of energy dissipation, using the tools of stochastic thermodynamics, can constrain and provide intuition for the correlations and configurations that emerge in a nonequilibrium process. We anticipate that the frameworks reviewed here can provide a starting point to address some of the unique phenomenology seen in biophysical systems and potentially replicate them in synthetic materials.

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