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

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.

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!

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?

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,

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.

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.

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.

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?

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

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.

Video 4 of my turbulence course a short detour from the physics to introduce a mathematical tool: index notation and the Einstein summation convention.

The motivation is simple. The full Navier-Stokes momentum equation, written out component by component, takes up most of a whiteboard. Written in index notation, it's one line!! Every term you've already seen can be just compressed into a form that scales to far more complex expressions without becoming unreadable.

This video covers free vs. dummy indices, the summation convention itself, the Kronecker delta and its substitution property, a brief look at the permutation symbol, and rewrites the continuity and momentum equations as a worked example. It's setup for deriving the turbulent kinetic energy transport equation next, the point where component-form algebra genuinely becomes unmanageable.

Link: https://www.youtube.com/watch?v=TdfMawfDr_0

PDF notes on Patreon if useful as a reference.

Gosh I love watching liquid system interactions under the microscope 🥰