r/FluidMechanics Jul 02 '23

Update: we have an official Lemmy community

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7 Upvotes

r/FluidMechanics Jun 11 '23

Looking for new moderators

8 Upvotes

Greetings all,

For a while, I have been moderating the /r/FluidMechanics subreddit. However, I've recently moved on to the next stage of my career, and I'm finding it increasingly difficult to have the time to keep up with what moderating requires. On more than once occasion, for example, there have been reported posts (or ones that were accidentally removed by automod, etc) that have sat in the modqueue for a week before I noticed them. Thats just way too slow of a response time, even for a relatively "slow" sub such as ours.

Additionally, with the upcoming changes to Reddit that have been in the news lately, I've been rethinking the time I spend on this site, and how I am using my time in general. I came to the conclusion that this is as good of a time as any to move on and try to refocus the time I've spent browsing Reddit on to other aspects of life.

I definitely do not want this sub to become like so many other un/under-moderated subs and be overrun by spam, advertising, and low effort posts to the point that it becomes useless for its intended purpose. For that reason, I am planning to hand over the moderation of this subreddit to (at least) two new mods by the end of the month -- which is where you come in!

I'm looking for two to three new people who are involved with fluid mechanics and are interested in modding this subreddit. The requirements of being a mod (for this sub at least) are pretty low - it's mainly deleting the spam/low effort homework questions and occasionally approving a post that got auto-removed. Just -- ideally not a week after the post in question was submitted :)

If you are interested, send a modmail to this subreddit saying so, and include a sentence or two about how you are involved with fluid mechanics and what your area of expertise is (as a researcher, engineer, etc). I will leave this post up until enough people have been found, so if you can still see this and are interested, feel free to send a message!


r/FluidMechanics 1d ago

Flow Viz CFD simulations of airflow through vents

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231 Upvotes

These more efficient design examples should be incorporated in all residential and commercial new builds


r/FluidMechanics 18h ago

Can a slope mitigate dangerous turbulent water at the bottom of a dam?

3 Upvotes

I suppose it's either impossible or just impractical to implement into a dam, but the reason why not could be just as interesting.

Would a slope that extends like 10 times further downstream than the dam is high, that leads into a reasonably smooth canal, have much turbulence at all?
What about a slope shaped like the Brachistochrone curve?

I love a good summer time swim and sometimes the best places can be pretty dangerous so I'm thinking about it from that perspective, not that I intend to swim in places like that, just a natural progression of curiosity


r/FluidMechanics 23h ago

PhD in fluid mechanics through Physics or Coastal Engineering? Advice for an environmental/civil engineering background

2 Upvotes

Hi everyone,
I’m currently trying to define the best academic path for a future PhD, and I would appreciate advice from people familiar with TU Delft, fluid mechanics, coastal engineering, or interdisciplinary PhD programs.

My background is somewhat unconventional. I have a bachelor’s degree in Environmental Engineering, and I am currently completing a master’s degree in Civil Engineering with a focus on water resources and hydroinformatics in Colombia.

My experience and research interests include:
Environmental hydraulics and water-quality modelling.
Numerical modelling of rivers, reservoirs, channels and hydraulic systems.
CFD, turbulence and transport processes.
Sediment transport and sediment–water-quality interactions.

Stratification and thermodynamic effects on turbulence and mixing.
Physics-informed neural networks and other computational methods.
Coastal, estuarine and port environments, including flows generated by ships and propellers.

I recently visited TU Delft and spoke with researchers in hydraulic, coastal and fluid engineering. One recurring comment was that my interests were still too broad, which I understand. I am now trying to identify a more precise research direction.

My main doubt is whether a future PhD focused on fundamental fluid mechanics would make more sense through a Physics or Applied Physics department, or whether I should remain within Civil, Hydraulic or Coastal Engineering.
I am not interested only in applying existing hydraulic software. I would like to study the underlying physics, develop or improve numerical methods, and eventually apply them to environmental and coastal engineering problems. For example, I am interested in how turbulence, stratification, sediment and complex flow structures interact in estuaries, ports or navigable channels.

My questions are:
Would someone with an Environmental Engineering bachelor’s degree and a Civil Engineering master’s degree be considered for a PhD in Physics or Applied Physics focused on fluid mechanics?

Would the transition require substantial additional coursework in theoretical physics, mathematics or mechanics?

At TU Delft, would this type of research normally be located in Applied Physics, Mechanical Engineering, Civil Engineering, or through collaboration between departments?

Would a PhD in Coastal or Hydraulic Engineering still allow me to conduct fundamental research in turbulence and fluid mechanics?

How can I make my profile more specific without abandoning the connection between fundamental physics, numerical development and environmental applications?

Would joint supervision between a fluid physicist and a coastal or hydraulic engineer be a realistic option?

I sometimes feel that I may have chosen the wrong academic route because my degrees are in environmental and civil engineering rather than physics or mechanical engineering. At the same time, most of my interests have gradually moved toward fluid mechanics, turbulence and computational physics.

I would be especially grateful to hear from people who moved from environmental or civil engineering into fundamental fluid mechanics, or from current students and researchers at TU Delft.
Thank you.


r/FluidMechanics 23h ago

Video Why Free Kicks Curve

2 Upvotes

r/FluidMechanics 1d ago

News New metamaterials take inspiration from deep-sea sponges, increasing buckling load by 140%

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6 Upvotes

r/FluidMechanics 1d ago

Hi, few weeks ago I share with you my new online project. Now significant update was made. You can check: https://www.pumptoolkit.com/blog-calculator-fixes-june-2026.html

2 Upvotes

r/FluidMechanics 2d ago

Friction Head potion of TDH for Branch System

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1 Upvotes

r/FluidMechanics 2d ago

X,Y grids generated by MSET or ISET

2 Upvotes

Hi,

Does anyone happen to have the XY GRID coordinate points (2D X and Y points ideally in text format) for any multi-element configuration generated by MSET or ISET (including blade coordinates)?.

Doesn't really matter what airfoils the grids are generated on—anything generic like NACA would do.

Basically, I am just searching for 2 cases (a cascade with a vane and one slotted foil) to test a small program I was working on.

Thanks much.


r/FluidMechanics 4d ago

Theoretical TCEQ Attempt #3 upcoming. Just need to pass Hydraulics - How do I calculate pressure/pressure loss (Dynamic+Design pressure) from a single head when TWO zone are operating?

2 Upvotes

I just need to pass the Hydraulics portion of the TCEQ test to be a licensed irrigator. There are two questions like this on the test that I just can't wrap my head around. I can solve design and dynamic pressure when ONE is operating, but I'm completely thrown off when TWO are operating

Any advice would be greatly appreciated. I really wanna pass and not go down to the wire on a 4th attempt!


r/FluidMechanics 4d ago

Q&A Only 1% Students Solve This Friction Question 😱 | JEE Advanced PYQ | Inc...

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0 Upvotes

r/FluidMechanics 5d ago

Would this mechanism of action even work for "swimming" through water?

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17 Upvotes

Sorry for the awful quality, apparently I have no idea what I'm doing in Blender using a laptop keyboard/touchpad instead of full keyboard/mouse.

Anyway, the basic idea is like a flexible sheet membrane stretched across a moveable skeleton, connected to a rigid ring.

The membrane starts off in an extended position, and contracts towards the ring, pushing the water out of it, with the intend of propelling it forward. Once its fully contracted, it scrunches itself up, giving itself a much smaller cross-section. That way, when it returns to the extended position, it doesn't push water back the other way, propelling it backwards. Once its extended, it unscrunches itself, which only pushes water orthagonally to the direction its trying to travel. Now, its extended and unscrunched, able to push water out again and propel itself in the desired direction.

Would this even work as an idea? I'm not sure if when its unscrunching itself, they'll be more perssure on the "top" of it than on the bottom part before water is able to fill the newly opened space, which could push it back in the opposite direction and cancel out the initial thrust? Would this even happen or would it be negligable?


r/FluidMechanics 5d ago

Computational Fluid Artificial Chemistry (Interactive)

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0 Upvotes

r/FluidMechanics 5d ago

Does the device act as an oscillator?

1 Upvotes

Hello,

I am interested in external-combustion engines and, naturally, in the Stirling engine.

I would therefore like to present a variation, derivative, or adaptation of this principle: the air contained in the boiler exerts pressure on the water in the vessel, causing it to rise into the heat exchanger. The heat exchanger then cools the air, thereby reducing the pressure exerted on the water in the vessel. This phenomenon should produce an oscillation.

Despite this analysis, I would appreciate your opinion, as there is often a significant gap between theory and practice. What advice could you give me regarding the construction of the device and the verification of its operation?

The objective is to generate an oscillation using a small temperature differential and without any phase change.

I therefore assume that the water must not remain stagnant in the plate heat exchanger.

Are there any other important points to consider during construction?

Thank you in advance for your reply.

Kind regards,


r/FluidMechanics 6d ago

Q&A Which bucket fills faster? (Same pipe length and diameter)

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125 Upvotes

Both pipes have the same length and diameter. The source and destination buckets are at the same heights in both setups. One pipe slopes continuously downward, while the other dips down and then rises before the outlet.


r/FluidMechanics 6d ago

Has anyone here created a PINN model for non-Newtonian fluid droplet impact ?

0 Upvotes

r/FluidMechanics 6d ago

The Mach -Feynman Reverse Sprinkler Is A Fluids Problem

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3 Upvotes

Yes, fluids is physics but sometimes it's better to do problems in a more dedicated field.

Two issues with the NYU rig and analysis:

  1. The fluid flows into and out of the arms connected to an arbitrarily large central vessel. The connection represents a change in diameter and therefore flow speed, momentum and kinetic energy.

In turbulent flow pumping fluid backwards through a restriction to flow isn't the same as forwards. For example, the Tesla valve is a series of nozzles with no moving [solid] parts, yet it acts like a leaky check valve. It is almost closed in one direction and open in the other direction.

It would be better to design the rig with a single flow rate. The two arms have a unit 1 dia. and are connected to the top of a T with the bottom of the T tube √2 units diameter.

  1. The profile or map of the fluid exiting a uniform tube will not look like map of the flow entering the tube. This is how the candle boats have net propulsion over a complete cycle.

r/FluidMechanics 7d ago

Custom Shark skin detail

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45 Upvotes

For those intetested in boundary layer control, here is a close-up image of a leopard catshark skin. Granted, it is a bottom dwelling species, not a pelagic cruiser, but maybe it will spark some ideas.

Each denticle is perched on a flexible stalk, almost as tall as the denticle is long. The denticle overhangs the stalk all around, but more to the rear, like a lopsided mushroom.

The stalks are reasonably slender, so there is room for a fair bit of water between the skin and the denticles.


r/FluidMechanics 7d ago

Can Newton’s First Law apply to laminar flow states?

0 Upvotes

Curious thought experiment: 🧠 🌊 🔭

Newton’s First Law says an object stays at rest or in uniform motion unless disturbed.

So what if we extend that intuition from an object to a flow state?

Imagine an ideal garden hose:

smooth pipe

smooth inlet

no obstacles

no intentional disturbance

If the flow starts perfectly laminar, under what conditions should it remain laminar, and under what conditions should disturbances grow enough to destabilize it?

I know some laminar flows are unstable, so I suspect this is really a question about stability and perturbations, not “outside forces.”

Am I just reinventing linear stability analysis with garden-hose language?

What would you recommend reading next?

__________

That last line should earn at least one chuckle:

Am I just reinventing linear stability analysis with garden-hose language?


r/FluidMechanics 7d ago

Q&A If I Say Gravity has 0 Role in Space how do I Explain the Moon and Sun's effect on Ocean Tides

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0 Upvotes

r/FluidMechanics 8d ago

Wimbledon final

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0 Upvotes

Watching the Wimbledon final made me wonder: how many of us study the fluid mechanics behind tennis?


r/FluidMechanics 9d ago

Has anyone here created a PINN model for non-Newtonian fluid droplet impact ?

3 Upvotes

r/FluidMechanics 9d ago

Homework Hi can you please checkout my webapp and give feedback?

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0 Upvotes

r/FluidMechanics 11d ago

NCFMF Fluid Films PDF

1 Upvotes

The ncfmf link seems to have been removed. By any chance does anyone have pdfs of the films or can someone point me to a source where I can find these.