scholarly journals The Effect of Oil Viscosity on Droplet Generation Rate and Droplet Size in a T-Junction Microfluidic Droplet Generator

Micromachines ◽  
2019 ◽  
Vol 10 (12) ◽  
pp. 808 ◽  
Author(s):  
Junyi Yao ◽  
Fan Lin ◽  
Hyun Kim ◽  
Jaewon Park
Keyword(s):  
Water Flow ◽  
Droplet Size ◽  
Droplet Generation ◽  
Generation Rate ◽  
Droplet Generator ◽  
Oil Viscosity ◽  
High Throughput Analysis ◽  
Oil Emulsion ◽  
Oil Flow ◽  
Flow Pressure

There have been growing interests in droplet-based microfluidics due to its capability to outperform conventional biological assays by providing various advantages, such as precise handling of liquid/cell samples, fast reaction time, and extremely high-throughput analysis/screening. The droplet-based microfluidics utilizes the interaction between the interfacial tension and the fluidic shear force to break continuous fluids into uniform-sized segments within a microchannel. In this paper, the effect of different viscosities of carrier oil on water-in-oil emulsion, particularly how droplet size and droplet generation rate are affected, has been investigated using a commonly used T-junction microfluidic droplet generator design connected to a pressure-controlled pump. We have tested mineral oils with four different viscosities (5, 7, 10, and 15 cSt) to compare the droplet generation under five different flow pressure conditions (i.e., water flow pressure of 30–150 mbar and oil flow pressure of 40–200 mbar). The results showed that regardless of the flow pressure levels, the droplet size decreased as the oil viscosity increased. Average size of the droplets decreased by approximately 32% when the viscosity of the oil changed from 5 to 15 cSt at the flow pressure of 30 mbar for water and 40 mbar for oil. Interestingly, a similar trend was observed in the droplet generation rate. Droplet generation rate and the oil viscosity showed high linear correlation (R2 = 0.9979) at the water flow pressure 30 mbar and oil flow pressure 40 mbar.

Analytical Modeling of Emulsion Flow at the Edge of a Steam Chamber During a Steam-Assisted-Gravity-Drainage Process

SPE Journal ◽  
2016 ◽  
Vol 21 (02) ◽  
pp. 353-363 ◽  
Author(s):  
Mahdie Mojarad ◽  
Hassan Dehghanpour
Keyword(s):  
Sensitivity Analysis ◽  
Production Rate ◽  
Flow Rate ◽  
Gravity Drainage ◽  
Oil Viscosity ◽  
Oil Emulsion ◽  
Steam Chamber ◽  
Steam Assisted Gravity Drainage ◽  
Oil Flow ◽  
Water In Oil Emulsion

Summary Recently, different models were proposed to describe two- and three-phase flow at the edge of a steam chamber developed during a steam-assisted-gravity-drainage (SAGD) process. However, 2D-scaled SAGD experiments and recent micromodel visualizations demonstrate that steam condensate is primarily in the form of microbubbles dispersed in the oil phase (water-in-oil emulsion). Therefore, the challenging question is: Can the multiphase Darcy equation be used to describe the transport of water as a discontinuous phase? Furthermore, the physical impact of water as a continuous phase or as microbubbles on oil flow can be different. Water microbubbles increase the apparent oil viscosity, whereas a continuous water phase decreases the oil relative permeability. Investigating the impact of these two phenomena on oil mobility at the steam-chamber edge and on overall oil-production rate during an SAGD process requires development of relevant mathematical models, which is the focus of this paper. In this paper, we develop an analytical model for lateral expansion of the steam chamber that accounts for formation and transport of water-in-oil emulsion. It is assumed that emulsion is generated as a result of condensation of steam, which penetrates into the heated bitumen. The emulsion concentration decreases from a maximum value at the chamber interface to zero far from the interface. The oil viscosity is affected by both temperature gradient caused by heat conduction and microbubble concentration gradient resulting from emulsification. We conduct a sensitivity analysis with the measured data from scaled SAGD experiments. The sensitivity analysis shows that, by increasing the value of m (temperature viscosity parameter), the effect of emulsification on oil-flow rate decreases. It also shows that the effect of temperature on oil mobility is much stronger than that of emulsion. We also compare the model predictions with field production data from several SAGD operations. Butler's model overestimates oil-production rate caused by the single-phase assumption, whereas the proposed model presents more-accurate oil-flow rate, supporting the fact that one should include emulsification effect in the SAGD analysis.

Variation of Zero Net Liquid Holdup in a Gas Liquid Cylindrical Cyclone Separator Below Operational Envelope

2020 ◽  
Author(s):  
Malay Jignesh Shah ◽  
Srinivas Swaroop Kolla ◽  
Ram S. Mohan ◽  
Ovadia Shoham
Keyword(s):  
Experimental Data ◽  
Water Flow ◽  
Operating Conditions ◽  
Extended Model ◽  
Gas Velocity ◽  
Oil Viscosity ◽  
Liquid Holdup ◽  
Cylindrical Cyclone ◽  
Oil Flow ◽  
Operational Envelope

Abstract Novel experimental and theoretical investigations are carried out on Zero Net Liquid Flow (ZNLF) in the upper part of the Gas-Liquid Cylindrical Cyclone (GLCC©) separator. Experimental data are acquired for the variation of the Zero Net Liquid Holdup (ZNLH) and the associated Churn region height for air-oil and air-water flow. The experiments are carried out at normal operating conditions below the GLCC Operational Envelope (OPEN) for Liquid Carry-Over (LCO). The ZNLH measurements for air-oil flow are higher than those for air-water flow. The Churn region height is higher for air-oil flow, as compared to the air-water flow, for the same operating conditions. The higher oil viscosity, which results in higher frictional and drag forces, leads to greater ZNLH for air-oil flow. The Churn region height is sensitive to the superficial gas velocity, whereby a small increase of gas velocity results in exponential growth of the Churn region height. The model developed by Karpurapu et al. (2018) for predicting the ZNLH at specific operational conditions just below the OPEN for LCO is extended to predict the ZNLH variation along the upper part of the GLCC below the OPEN for LCO, as well as the associated Churn region height. The predictions of the developed extended model for the ZNLH variation compared to the acquired experimental data showing discrepancies of 8% and 3%, respectively, for air-oil and air-water flows.

Effect of oil viscosity on the flow structure and pressure gradient in horizontal oil–water flow

2012 ◽  
Vol 90 (8) ◽  
pp. 1019-1030 ◽  
Author(s):  
N. Yusuf ◽  
Y. Al-Wahaibi ◽  
T. Al-Wahaibi ◽  
A. Al-Ajmi ◽  
A.S. Olawale ◽  
...  
Keyword(s):  
Pressure Gradient ◽  
Water Flow ◽  
Flow Structure ◽  
Oil Viscosity ◽  
Oil Water

Experimental Characterization of Oil-Refrigerant Two-Phase Flow

2000 ◽  
Author(s):  
V. T. Lacerda ◽  
A. T. Prata ◽  
F. Fagotti
Keyword(s):  
Flow Visualization ◽  
Two Phase Flow ◽  
Working Fluid ◽  
Phase Flow ◽  
Oil Viscosity ◽  
Two Phase ◽  
Mixture Flow ◽  
Horizontal Tubes ◽  
Constant Diameter ◽  
Oil Flow

Abstract Several phenomena occurring inside refrigerating systems depend on the interaction between the refrigeration oil and the refrigerant working fluid. Regarding the refrigeration cycle, good miscibility of oil and refrigerant assure easy return of circulating oil to the compressor through the reduction of the oil viscosity. Inside the compressor the lubricant is mainly used for leakage sealing, cooling of hot elements and lubrication of sliding parts. In the compressor bearing systems the presence of refrigerant dissolved in the oil greatly influences the performance and reliability of the compressor due to the outgassing experienced by sudden changes in temperature and pressure resulting in a two-phase mixture with density and viscosity strongly affecting the lubricant characteristics. A general understanding of the oil-refrigerant mixture flow is crucial in developing lubrication models to be used in analysis and simulation of fluid mechanics problems inside the compressor. In the present investigation the refrigeration oil flow with refrigerant outgassing is explored experimentally. A mixture of oil saturated with refrigerant is forced to flow in two straight horizontal tubes of constant diameter. One tube is used for flow visualization and the other is instrumented for pressure and temperature measurements. At the tubes inlet liquid state prevails and as flow proceeds the pressure drop reduces the gas solubility in the oil and outgassing occurs. Initially small bubbles are observed and eventually the bubble population reaches a stage where foaming flow is observed. The flow visualization allowed identification of the two-phase flow regimes experienced by the mixture. Pressure and temperature distributions are measured along the flow and from that mixture quality and void fraction were estimated.

A Surfactant-Free Microfluidic Process for Fabrication of Multi-Hollow Polyimide Aerogel Particles

2020 ◽  
Vol 35 (5) ◽  
pp. 481-492
Author(s):  
Y. M. Yao ◽  
P. Joo ◽  
S. C. Jana
Keyword(s):  
Thermal Insulation ◽  
Supercritical Drying ◽  
Bet Surface Area ◽  
Liquid Droplets ◽  
Emulsion System ◽  
Droplet Generator ◽  
Flow Rates ◽  
Oil Emulsion ◽  
Gel Particles ◽  
Microfluidic Flows

Abstract This work focuses on fabrication of multi-hollow polyimide gel and aerogel particles from a surfactant-free oil-in-oil emulsion system using a microfluidic droplet generator operating under dripping mode. The multi-hollow gel and aerogel particles have strong potential in thermal insulation. Under jetting and tip-streaming regime of microfluidic flows, droplets are generated with no occluded liquid phase. The present study investigates a means of designing polyimide gel particles with plurality of internal liquid droplets by strategically manipulating the flow rates of the continuous and dispersed phase liquids through the microfluidic droplet generator. The multi-hollow polyimide aerogel particles obtained after supercritical drying of the gel particles present mesopores, high BET surface area, and excellent prospect for thermal insulation.

Experimental investigation of two-phase water–oil flow pressure drop in inclined pipes

2016 ◽  
Vol 74 ◽  
pp. 169-180 ◽  
Author(s):  
Pedram Hanafizadeh ◽  
Amir Karimi ◽  
Alireza Taklifi ◽  
Alireza Hojati
Keyword(s):  
Experimental Investigation ◽  
Pressure Drop ◽  
Two Phase ◽  
Oil Flow ◽  
Flow Pressure ◽  
Phase Water ◽  
Inclined Pipes

Study on Propylene Recovery in a Dispersed Absorption System-(Water-in-Oil) Emulsion System

2011 ◽  
Vol 383-390 ◽  
pp. 6151-6155
Author(s):  
Hong Jing Liu ◽  
Ying Zhang ◽  
Hui Yao ◽  
Wei Zhao
Keyword(s):  
Droplet Size ◽  
Absorption Rate ◽  
Volume Fraction ◽  
Dispersed Phase ◽  
Emulsion System ◽  
Absorption System ◽  
Oil Emulsion ◽  
Stirring Rate ◽  
Water In Oil Emulsion ◽  
System Water

The purpose of the paper is to investigate propylene recovery by a new absorption system, namely water-in-oil emulsion absorbent. Water in oil emulsion, in which kerosene used as oil phase with dispersed water droplet, is prepared to be as absorbent to absorb propylene. The effect of volume fraction dispersed phase, dispersed droplet size, and the stirring rate on propylene absorption rate are researched. Experimental results indicate that the absorption rate of propylene can increase 20% compared with traditional absorption method. The volume fraction dispersed phase should be appropriate, otherwise the enhancement absorption can not be attained. The appropriate number is 0.05 for this dispersion. The smaller droplet size of dispersed phase as well as the faster stirring rate can increase the propylene absorption rate. The mechanism of enhancement propylene absorption is attributed to the intensive turbulence in boundary layer between gas and liquid due to the movement of dispersed water droplets.

scholarly journals Application of Implicit Pressure-Explicit Saturation Method to Predict Filtrated Mud Saturation Impact on the Hydrocarbon Reservoirs Formation Damage

Mathematics ◽  
2020 ◽  
Vol 8 (7) ◽  
pp. 1057 ◽  
Author(s):  
Mingxuan Zhu ◽  
Li Yu ◽  
Xiong Zhang ◽  
Afshin Davarpanah
Keyword(s):  
Porous Media ◽  
Water Saturation ◽  
Drilling Fluid ◽  
Formation Damage ◽  
Drilling Mud ◽  
Oil Viscosity ◽  
The Core ◽  
Oil Flow ◽  
Lower Porosity ◽  
Saturation Method

Hydrocarbon reservoirs’ formation damage is one of the essential issues in petroleum industries that is caused by drilling and production operations and completion procedures. Ineffective implementation of drilling fluid during the drilling operations led to large volumes of filtrated mud penetrating into the reservoir formation. Therefore, pore throats and spaces would be filled, and hydrocarbon mobilization reduced due to the porosity and permeability reduction. In this paper, a developed model was proposed to predict the filtrated mud saturation impact on the formation damage. First, the physics of the fluids were examined, and the governing equations were defined by the combination of general mass transfer equations. The drilling mud penetration in the core on the one direction and the removal of oil from the core, in the other direction, requires the simultaneous dissolution of water and oil flow. As both fluids enter and exit from the same core, it is necessary to derive the equations of drilling mud and oil flow in a one-dimensional process. Finally, due to the complexity of mass balance and fluid flow equations in porous media, the implicit pressure-explicit saturation method was used to solve the equations simultaneously. Four crucial parameters of oil viscosity, water saturation, permeability, and porosity were sensitivity-analyzed in this model to predict the filtrated mud saturation. According to the results of the sensitivity analysis for the crucial parameters, at a lower porosity (porosity = 0.2), permeability (permeability = 2 mD), and water saturation (saturation = 0.1), the filtrated mud saturation had decreased. This resulted in the lower capillary forces, which were induced to penetrate the drilling fluid to the formation. Therefore, formation damage reduced at lower porosity, permeability and water saturation. Furthermore, at higher oil viscosities, due to the increased mobilization of oil through the porous media, filtrated mud saturation penetration through the core length would be increased slightly. Consequently, at the oil viscosity of 3 cP, the decrease rate of filtrated mud saturation is slower than other oil viscosities which indicated increased invasion of filtrated mud into the formation.

scholarly journals Microstructure Adjustment of Spherical Micro-samples for High-Throughput Analysis Using a Drop-on-Demand Droplet Generator

Materials ◽  
2019 ◽  
Vol 12 (22) ◽  
pp. 3769 ◽  
Author(s):  
Moqadam ◽  
Mädler ◽  
Ellendt
Keyword(s):  
High Throughput ◽  
Metal Droplet ◽  
Sensitivity Study ◽  
Droplet Generator ◽  
High Throughput Analysis ◽  
Drop On Demand ◽  
Critical Process Parameters ◽  
Critical Process ◽  
Good Agreement ◽  
Cooling Model

: High-throughput methods for the development of structural materials require samples which are comparable in geometric dimensions and microstructure. Molten metal droplet generators produce thousands of droplets and microspheres from specific alloys with very good reproducibility. In this study, droplet generation experiments were conducted with two alloys and their microstructure was analyzed regarding secondary dendrite arm spacing (SDAS) in order to determine cooling rates during solidification. A droplet cooling model was developed, and predictions showed good agreement with the experimental data. Finally, a sensitivity study was conducted using the validated model to identify critical process parameters which have great impact on the resulting microstructure and need to be well-controlled to achieve the desired reproducibility in microstructure.

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