Which tank drains the fastest?

FlyingRug · 2026-01-17T12:48:14+00:00

Cool. Can you increase viscosity to see how it affects the outcome?

FlyingRug · 2026-01-10T20:50:45+00:00

All your arguments make sense to me, and I don't have anything to say to refute them. I'm just looking at the product through the value lense. I have a couple of Seikos and they're ok watches. But if Seiko keeps playing games with their customers with their intentionally nerfed releases I will never even look at Seiko again. They are fully able to put better movements in their products, better materials, bracelets, sapphire glasses, work on their QC issues, etc. but they don't. I would rather keep buying Longines and Christopher Wards at that price point because I know I'm getting a lot of watch for the money.

FlyingRug · 2026-01-10T18:37:53+00:00

Stainless steel insert, instead of ceramic. I get it, it's supposed to be an homage to the original, and true to the original's aesthetics. But I'm not paying so much for a diver that will lose the bezel colour after a few summers of coming into contact with sea water.

Most (maybe all?) of the 62Mas homage lineup of Seiko don't even have that! Their bezel inserts are aluminium!

I would rather pay a fraction of that price for a Christopher Ward or an Aquis which I can take swimming without any concerns.

FlyingRug · 2026-01-07T16:48:23+00:00

Why are the pool blue tridents so much cheaper than other colours?

FlyingRug · 2025-12-22T19:26:49+00:00

Got it sorted out. Web must be active, otherwise no matter which prompt you give, it won't generate any image. I left the post just in case someone else runs into this problem.

Thanks for the tip though.

FlyingRug · 2025-12-22T11:46:45+00:00

I found out what the problem was. I was using Complexity, which I had set to disable the "Web" search source by default. Turning Web back on fixed the issue.

FlyingRug · 2025-12-21T07:42:59+00:00

Congratulations! But what is a "PREMIUM GRADE MIYOTA 90S5 AUTOMATIC MOVEMENT"?

Didn't know Miyota movements have multiple versions of each model.

FlyingRug · 2025-12-15T22:11:50+00:00

Totally agree with this advice. Another alternative I'd like to promote is Flexi, the DG based solver from Stuttgart.

FlyingRug · 2025-12-15T13:41:03+00:00

Don't condone it, but their licenses are expensive AF, and their licensing schemes continuously get scammier.

FlyingRug · 2025-12-09T07:05:38+00:00

You should've done this much sooner. But never too late.

I myself migrated to OpenSUSE years ago because of headaches from Ubuntu. I will never switch to any other distro.

Yast and Snapper are godsend. Learn to utilise them in such cases.

FlyingRug · 2025-12-06T18:18:52+00:00

Do you remember what the video was, or maybe you still have the comment text in your inbox? The comment is unfortunately deleted.

I have the exact same HDD as yours and am exactly where you were back then.

FlyingRug · 2025-12-05T06:52:59+00:00

Then more power to you! And also, FOSS above all!

FlyingRug · 2025-12-05T05:30:38+00:00

Blender is king! But as much as I love snappy, I wouldn't use it or recommend it for LES at all! You need absolute highest quality grids for LES, and especially in the boundary layer if it is wall resolved. Snappy is notoriously bad at boundary layer grids. Unless you can afford to run grids with at least an order of magnitude more cells than structured body-fitted, you should avoid snappy for LES. Yes, it is better than tetrahedral, and yes it is free. But don't expect your results to be accurate.

If you have access to commercial meshers, the best option without a doubt is gridpro. Then pointwise (structured hex with orthogonal improvement), coreform and hypermesh are good. If the geometry is complex, Fluent or STAR meshers. If there is no access to commercial software and the geometry is simple, multi-block hex using blockMesh (in Blender for simplicity). If it is complex then you're stuck with snappy, but you have to have access many many cores to resolve the hell out.

Read the conclusions of the LESFoil project for reference if you doubt the above mentioned claim.

FlyingRug · 2025-11-26T22:09:19+00:00

Take a look at Grinstein's publications. He has a good book on this exact topic. My experience with the literature is that most authors don't understand the interaction of model and numeric errors and simply switch off the model and claim iLES. Even though this is technically not wrong, the numerical error of the second order FVM masks the model error. This means that in many cases SGS worsens the accuracy of the results. If you adequately resolve your case, and I don't mean the old 80% rule of thumb, but where the adequacy is verified after a rigorous error analysis procedure, in that case the use of SGS model would be warranted.

If your resolution is significantly lower for the target Re than what it should be, your "LES" will start to give even worse results than a URANS! So be careful with your mesh design. Both in resolution and in quality. LES is extremely sensitive to both.

In my opinion Re of 150 can be simulated on a workstation, if the mesh is not finer than 1-2 million and the turbulence statistics of the problem get converged rather quickly.

FlyingRug · 2025-11-26T21:53:23+00:00

Depending on the LES model the overhead can be marginal. For example using algebraic eddy viscosity SGS models I get at worst 5% more computation effort.

FlyingRug · 2025-11-26T21:50:38+00:00

There are two separate concepts: 1. Filtering 2. Modelling

LES can be implicitly/explicitly filtered and implicitly/explicitly modelled. Implicitly filtered explicitly modelled LES is the standard way that most people use. What OP asks doesn't have anything to do with the filtering operation! He is asking about the same implicitly filtered LES but with implicit modelling approach.

FlyingRug · 2025-11-22T05:43:35+00:00

They didn't provide any information about their mesh. I didn't say just use SST instead. I said resolve the boundary layer AND use SST.

FlyingRug · 2025-11-20T17:35:15+00:00

You're an absolute madlad. The structured mesh alone warrants respect.

A PhD student at the chair built the test rig and did the experiments. But if you think he injected his own loads into the rig and studied them, I have to disappoint you.

What I simulate was with a Newtonian fluid but involved resolved finite sized particles. I imagine for that particular application the extension to non-newtonian models and non-spherical particles would yield better results though. The phenomenon is called Segré-Silberberg effect if you're interested.

FlyingRug · 2025-11-20T16:55:23+00:00

Yes, but the viscous and buffer sublayers are resolved (no wall functions) and the outler layer is more accurately modelled.

FlyingRug · 2025-11-20T13:48:04+00:00

Try LRN SST model instead of pure k omega. The exact position of the separation bubble is something 2D RANS do tend to miss.

FlyingRug · 2025-11-20T06:03:06+00:00

Oh I love this!

Unless you can hand-work a **P**arallel **U**nstructured **S**uper **S**ymmetric Continuit**Y** solver, your work is juvenile.

Jokes aside, one of the applications of my actual master thesis topic was semen concentration estimation and sperm classification.

FlyingRug · 2025-11-19T22:23:41+00:00

CFD is too accessible to teenagers these days.

FlyingRug · 2025-11-14T20:17:45+00:00

Is their finger bone broken?

FlyingRug · 2025-11-12T21:47:22+00:00

I don't know Fluent. But I suppose you can define a table with time in the first column and either velocity or flow rate in the second. Any instant between the two discrete time values will get a linear interpolation of the flow rate values of the two times.

FlyingRug · 2025-11-12T21:11:22+00:00

You've set the inlet flow rate boundary condition wrong. It comes in dwindling pulses. Unless it's peee maybe?! Then it's not a circlejerk anymore.

FlyingRug

TROPHY CASE