Numerical Simulation of Oil-Droplet Cleavage by Surfactant

1996 ◽  
Vol 118 (2) ◽  
pp. 201-209 ◽  
Author(s):  
Xiaoyi He ◽  
Micah Dembo

We present numerical computations of the deformation of an oil-droplet under the influence of a surface tension gradient generated by the surfactant released at the poles (the Greenspan experiment). We find this deformation to be very small under the pure surface tension gradient. To explain the large deformation of oil droplets observed in Greenspan’s experiments, we propose the existence of a phoretic force generated by the concentration gradient of the surfactant. We show that this hypothesis successfully explains the available experimental data and we propose some further tests.

Author(s):  
S. Kudriakov ◽  
E. Studer ◽  
M. Kuznetsov ◽  
J. Grune

A set of experiments performed at Karlsruhe Institute of Technology (KIT) in the framework of the LACOMECO European project is devoted to flame propagation in an obstructed large scale facility A3 (of 8 m height and 33 m3 volume) with initially vertical hydrogen concentration gradients. Almost linear positive and negative (relative to gravity) concentration gradients are created prior to ignition in the range from 4% to 13%, and the process of flame acceleration is investigated depending on hydrogen concentration gradient and ignition positions. In this paper we describe the A3 facility and analyse the experimental data obtained during the project. The results of numerical simulation performed using Europlexus code are presented together with the critical discussions and conclusions.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Ilyas Al-Kindi ◽  
Tayfun Babadagli

AbstractThe thermodynamics of fluids in confined (capillary) media is different from the bulk conditions due to the effects of the surface tension, wettability, and pore radius as described by the classical Kelvin equation. This study provides experimental data showing the deviation of propane vapour pressures in capillary media from the bulk conditions. Comparisons were also made with the vapour pressures calculated by the Peng–Robinson equation-of-state (PR-EOS). While the propane vapour pressures measured using synthetic capillary medium models (Hele–Shaw cells and microfluidic chips) were comparable with those measured at bulk conditions, the measured vapour pressures in the rock samples (sandstone, limestone, tight sandstone, and shale) were 15% (on average) less than those modelled by PR-EOS.


2008 ◽  
Vol 602 ◽  
pp. 209-218 ◽  
Author(s):  
J. J. J. GILLISSEN ◽  
B. J. BOERSMA ◽  
P. H. MORTENSEN ◽  
H. I. ANDERSSON

We use direct numerical simulation to study turbulent drag reduction by rigid polymer additives, referred to as fibres. The simulations agree with experimental data from the literature in terms of friction factor dependence on Reynolds number and fibre concentration. An expression for drag reduction is derived by adopting the concept of the elastic layer.


1996 ◽  
Vol 17 (4) ◽  
pp. 72-81 ◽  
Author(s):  
ALI G. BUDIMAN ◽  
C. FLORIJANTO ◽  
J. W. PALEN

SPE Journal ◽  
2013 ◽  
Vol 18 (03) ◽  
pp. 440-447 ◽  
Author(s):  
C.C.. C. Ezeuko ◽  
J.. Wang ◽  
I.D.. D. Gates

Summary We present a numerical simulation approach that allows incorporation of emulsion modeling into steam-assisted gravity-drainage (SAGD) simulations with commercial reservoir simulators by means of a two-stage pseudochemical reaction. Numerical simulation results show excellent agreement with experimental data for low-pressure SAGD, accounting for approximately 24% deficiency in simulated oil recovery, compared with experimental data. Incorporating viscosity alteration, multiphase effect, and enthalpy of emulsification appears sufficient for effective representation of in-situ emulsion physics during SAGD in very-high-permeability systems. We observed that multiphase effects appear to dominate the viscosity effect of emulsion flow under SAGD conditions of heavy-oil (bitumen) recovery. Results also show that in-situ emulsification may play a vital role within the reservoir during SAGD, increasing bitumen mobility and thereby decreasing cumulative steam/oil ratio (cSOR). Results from this work extend understanding of SAGD by examining its performance in the presence of in-situ emulsification and associated flow of emulsion with bitumen in porous media.


2018 ◽  
Vol 3 (3) ◽  
Author(s):  
Dong Song ◽  
Baowei Song ◽  
Haibao Hu ◽  
Xiaosong Du ◽  
Peng Du ◽  
...  

2000 ◽  
Author(s):  
Fahua Gu ◽  
Abraham Engeda ◽  
Mike Cave ◽  
Jean-Luc Di Liberti

Abstract A numerical simulation is performed on a single stage centrifugal compressor using the commercially available CFD software, CFX-TASCflow. The steady flow is obtained by circumferentially averaging the exit fluxes of the impeller. Three runs are made at design condition and off-design conditions. The predicted performance is in agreement with experimental data. The flow details inside the stationary components are investigated, resulting in a flow model describing the volute/diffuser interaction at design and off-design conditions. The recirculation and twin vortex structure are found to explain the volute loss increase at lower and higher mass flows, respectively.


2021 ◽  
Vol 1022 ◽  
pp. 194-202
Author(s):  
R.Kh. Dadashev ◽  
R.A. Kutuev

The experimental study results of the melts concentration dependence of the surface tension of the four-component indium-tin-lead-bismuth system and its constituent binary systems of indium-tin, indium-lead, indium-bismuth, tin-lead, tin-bismuth, lead-bismuth are presented in the paper. It is shown that the concentration dependence of the melts surface tension of the In-Sn-Pb-Bi four-component system can be predicted from the data on ST (surface tension) values of lateral binary systems. Features in the ST isotherms in the form of a minimum are observed only in the indium-tin lateral system from all lateral binaries. A distinctive feature of the detected minimum is that the minimum depth slightly exceeds the experimental error. Therefore, in addition to the fact that the area of average compositions was studied more thoroughly, we carried out the surface tension measurements by two independent methods. The experimental data obtained by both methods coincide within the experimental error and indicate the extremum availability on ST isotherms. Thus, ST experimental studies by two independent methods confirmed the presence of a flat minimum on ST isotherms of the indium-tin binary system increasing the reliability of the obtained data. The obtained outcomes and their comparison with experimental data have shown that the considered models for predicting surface properties based on data due to similar properties of lateral binary systems adequately reflect the experimental dependences. However, the prediction model based on Kohler's method of excess values describes the experimental curves more accurately.


Author(s):  
Francisco J. Arias ◽  
Salvador A. De Las Heras

Abstract In this work, consideration is given to capillary convection on ferrofluids from the concentration gradient induced when a nonhomogeneous magnetic field is applied. It is known that mass transfer along an interface between two fluids can appear due to a gradient of the surface tension in the so-called Marangoni effect (or Gibbs–Marangoni effect). Because the surface tension is both thermal and concentration dependent, Marangoni convection can be induced by either a thermal or a concentration gradient, where in the former case, it is generally referred as thermocapillary convection. Now, it has been theoretically and experimentally demonstrated that a ferrofluid under the action of a non-homogeneous magnetic field can induce a concentration gradient of suspended magnetic nanoparticles, and also the effect of Fe3O4 nanoparticles on the surface tension has been measured. Therefore, by deductive reasoning and taking into account the above mentioned facts, it is permissible to infer ferrohydrodynamic capillary convection on magnetic fluids under the presence of a magnetic gradient field. Utilizing a simplified physical model, the phenomenon was investigated and it was found that ferrohydrodynamic-Marangoni convection could be induced with particle size in the range up to 10 nm, which is the range of magnetic fluids to escape magnetic agglomeration.


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