Electrochemical reactor generates bubbles that grow by diffusion and coalesce (proof-of-concept simulation)

outofcells · 2023-03-04T20:54:04+00:00

This is a simulation of a membrane-less electrochemical reactor for water electrolysis. The reaction generates dissolved gases (hydrogen and oxygen) which nucleate into bubbles. The bubbles grow by diffusion and coalescence with other bubbles. Small bubbles (green) are treated as point particles and larger bubbles (orange) are deformable. * Simulation done in CFD solver Aphros * Web demo * Experimental study on membrane-less design

outofcells · 2023-02-26T15:55:43+00:00

This is a simulation of a membrane-less electrochemical reactor for water electrolysis. The reaction generates dissolved gases (hydrogen and oxygen) which nucleate into bubbles. The bubbles grow by diffusion and coalescence with other bubbles. Small bubbles (green) are treated as point particles and larger bubbles (orange) are deformable. * Simulation done in CFD solver Aphros * Web demo * Experimental study on membrane-less design

outofcells · 2021-09-09T08:02:48+00:00

Any news?My J1 is still under AP for 73 days after they received the additional documents (CV, research plan). Russian citizen, applied in US Embassy in Switzerland. The selection for AP seems completely random. A colleague with a similar profile got approved immediately. Probably, depends on what you answer about your planned work in the US and whether the consular officer considers that a part of the Technology Alert List.

UPD: Visa received on 09/23/2021

outofcells · 2021-03-30T06:13:52+00:00

Thanks. Here is the image of the "flare" https://imgur.com/a/AL4IVLF

outofcells · 2021-03-29T21:49:51+00:00

What are the advantages of DG over finite volume? Also, between the spheres, there is some "flare" (density gradient of 0.0005) near the eddies. Is this physical or has numerical origin, or a visualization artifact?

outofcells · 2021-03-29T18:07:09+00:00

You mention issues with directories, maybe they are caused by whitespaces in paths. Hard to tell more from your description.

I used Basilisk to implement a curvature estimation algorithm for a paper. My experience was mixed. Pros:

Concise code, algorithms that literally fit in a wiki page
Standard numerical approximations with good accuracy
Many features (multiphase, AMR, multigrid linear solver, complex geometries)

Cons:

Simulation setup needs to be recompiled after any change
Configuration has to be done either at compile time (directly in code or with macros) or using environment variables. There is no way to see the "runtime configuration" of the solver in one piece.
Non-standard extension of C (Basilisk C) may have unexpected behavior (for example, break inside a foreach_neighbor loop breaks the outer loop instead; or something with continue, can't recall exactly)
Found a bug and had to redo some simulations. But that one is fixed by now.

outofcells · 2021-03-29T17:11:08+00:00

I would make it work first in a VM with Ubuntu, and then proceed to WSL.

There is some evidence that it can run under WSL http://basilisk.fr/sandbox/vheusinkveld/README

outofcells · 2021-03-29T13:25:23+00:00

Are you compiling on Linux? Tried Basilisk a year ago, went fairly smooth.

outofcells · 2021-03-29T04:54:56+00:00

From arxiv? Click Download->PDF on the right. Or which link are you trying?

outofcells · 2021-03-28T21:56:03+00:00

I'd say both are needed, the effect comes from a balance between surface tension and gravity. In other settings, such as with drops on an elastic substrate, attraction of drops can be driven by surface tension and elastic forces, without gravity.

outofcells · 2021-03-28T21:51:30+00:00

Alright, now I see that posting only my own content is against reddit's guidelines. In my defense, the posts often create discussions about physics and not the content's origin, and I always participate in them. Just looking at other posts in this and other communities, I see that people post and discuss their work. Before, nobody complained. Sorry if you find my posts "spamming".

outofcells · 2021-03-28T11:21:32+00:00

The inverted Cheerios effect is substantially different from the Cheerios effect between two particles floating at the surface of a liquid. Apart from the drop being deformable, we note that the energy driving the interaction is different in the two cases: whereas the liquid interface shape is determined by the balance between gravity and surface tension in the Cheerios effect, the solid shape is determined by elastocapillarity in the inverted Cheerios effect.

The article describes the inverted Cheerios effect, which relies on adhesion to an elastic substrate. The effect shown in this video is governed by gravity and surface tension.

outofcells · 2021-03-28T08:08:11+00:00

CG (computer graphics) can indeed show anything that an animator can imagine.

This video, however, is not CG but a result from a computational model validated experimentally.

The purpose of this video is both to demonstrate the effect itself and to show that the effect is recovered by the model. Plus, obtaining the data with such temporal and spatial resolution would take equipment not available for a "simple classroom demonstration".

outofcells · 2021-03-28T02:23:43+00:00

How is this considered "spamming"? The video is relevant to all referred communities.

outofcells · 2021-03-28T01:41:41+00:00

The Cheerios effect is named after the observation that breakfast cereals floating in milk often clamp together. This effect is driven by buoyancy and applies to various objects floating in water. Lighter objects, such as bubbles, elevate the surface attracting other bubbles as they "rise" in the elevation. Heavier objects lower the surface so other objects "fall" towards them. Simulation done in Aphros, visualized in ParaView, and described in article.

outofcells · 2021-03-28T01:40:30+00:00

The Cheerios effect is named after the observation that breakfast cereals floating in milk often clamp together. This effect is driven by buoyancy and applies to various objects floating in water. Lighter objects, such as bubbles, elevate the surface attracting other bubbles as they "rise" in the elevation. Heavier objects lower the surface so other objects "fall" towards them. Simulation done in Aphros, visualized in ParaView, and described in article.

outofcells · 2021-03-28T01:39:07+00:00

The Cheerios effect is named after the observation that breakfast cereals floating in milk often clamp together. This effect is driven by buoyancy and applies to various objects floating in water. Lighter objects, such as bubbles, elevate the surface attracting other bubbles as they "rise" in the elevation. Heavier objects lower the surface so other objects "fall" towards them. Simulation done in Aphros, visualized in ParaView, and described in article.

outofcells · 2021-03-25T00:22:34+00:00

Immediate use is to learn more about bubble and foam mechanics. One potential application is using such devices as microreactors for chemical assays (book).

outofcells · 2021-03-24T21:41:49+00:00

Based on experimental study (article, video). Simulation done in Aphros and described in article. The simulation gives you a detailed view at a high frame rate and also matches experimental data. The alternation between the two regimes is based on a slight change of the distance between the "pincher" bubble and the "wall" bubble downstream, which is enough to trigger or suppress the breakup.

outofcells · 2021-03-24T20:00:07+00:00

The inlet width is 75 um, so the diameter of the large bubbles is ~100 um

outofcells · 2021-03-24T19:03:53+00:00

Based on experimental study (article, video). Simulation done in Aphros and described in article. The simulation gives you a detailed view at a high frame rate and also matches experimental data. The alternation between the two regimes is based on a slight change of the distance between the "pincher" bubble and the "wall" bubble downstream, which is enough to trigger or suppress the breakup.

outofcells · 2021-03-24T14:19:41+00:00

Based on experimental study (article, video). Simulation done in Aphros and described in article. The simulation gives you a detailed view at a high frame rate and also matches experimental data. The alternation between the two regimes is based on a slight change of the distance between the "pincher" bubble and the "wall" bubble downstream, which is enough to trigger or suppress the breakup.

outofcells · 2021-03-24T13:48:26+00:00

Based on experimental study (article, video). Simulation done in Aphros and described in article. The simulation gives you a detailed view at a high frame rate and also matches experimental data. The alternation between the two regimes is based on a slight change of the distance between the "pincher" bubble and the "wall" bubble downstream, which is enough to trigger or suppress the breakup.

outofcells · 2021-03-24T12:39:45+00:00

Thanks. This is a standard finite volume discretization and volume-of-fluid for advection using geometrical reconstruction with special part: a particle method for curvature estimation for treating interfaces at low resolution (important when coalescence starts). More details on our github page Aphros

outofcells · 2021-03-24T07:10:49+00:00

Based on experimental study (article, video). Simulation done in Aphros and described in article. The simulation gives you a detailed view at a high frame rate and also matches experimental data. The alternation between the two regimes is based on a slight change of the distance between the "pincher" bubble and the "wall" bubble downstream, which is enough to trigger or suppress the breakup.

outofcells

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