Tiny vanes glued to planes promise big savings for US Air Force

[jmward01]

Meanwhile they likely have hundreds or even thousands of lbs of dead equipment in them that accumulates as they are updated over the years. At least that is what happened to the P-3. Removing things is often a lot harder than adding them unfortunately.

[crooked-v]

Is that "dead equipment" as in "literally doesn't work", or is that "dead equipment" as in "nobody's used it in 35 years but one of the many edge cases involved in fighting a war will inevitably call for it"?

[dghlsakjg]

Slap an inop tag on it and keep moving.

[throw0101a]

Perhaps worth nothing that the last C-17 produced was in 2015, after which the closed the Long Beach plant:

* https://en.wikipedia.org/wiki/Boeing_C-17_Globemaster_III

[nradov]

It's so crazy that we shut down working production lines without having a replacement ready to go.

[titanomachy]

> 1% reduction in fuel consumption... will save $14 million dollars per year

Implying that the US air force spends $1.4 billion a year on fuel just for the C-17.

[bunabhucan]

Some of the fuel comes from mid-air refueling.

The USAF used the baseline fuel price in earlier studies to determine if it made economic sense to re-engine the B-52.

[jmward01]

A billion here, a billion there. Pretty soon you are talking real money.

[datadrivenangel]

Sounds not unlikely...

[Havoc]

1 percent gain from that seems wild.

I wonder how they arrived at this. Seems like it would be ideal for some sort of evolutionarily algo perhaps

[calmbonsai]

These are simply vortex generators which have been a post-production modification in many models of GA aircraft (most notably Rutan canard models) for decades.

They induce turbulent flow (vortices) which, under the correct circumstances, can actually benefit range, albeit, at the cost of overall lift efficiency across the originally designed flight envelope.

To use Randall Munroe's "Thing Explainer" vocabulary, they enable the aircraft to "go slower better", but at the expense of making it "go faster worse".

[jlkuester7]

> Just remember that the brake pads on your car are stuck on with glue next time you tap the pedal.

Unrelated to the article's point, but what? Maybe the layers of the pad itself are glued together, but no brake pads I have every changed have been stuck to the car with glue in any way. (They are held in place with metal brackets which allow them to slide along a small track when compressed by the brake pistons....)

[andrewflnr]

I assume they're talking about the bond between the metal frame that interacts with the brackets and the actual pad material itself, made of sintered metal or ceramic or something.

[dghlsakjg]

I think they mean the interface between the wear material and the backing.

I'm not entirely sure that it is just glue, but the flip side is that the wear material is, well, wear material that wears away over time, so mechanical attachment needs to not interfere with that.

Plus, if the wear material did come loose from the backing, it would likely make a bit of a racket rattling around (like a brake pad without its anti-rattle clip), but it doesn't really have anywhere to go since it is surrounded by caliper and rotor, and would probably work just fine since the backing is there to spread out the force from the piston evenly along the wear material. That force would still get spread out, the wear material might just shift a few mm.

[bombcar]

Glue can be quite strong.

I remember hearing that the 26 ton ceiling collapse on the big dig https://en.wikipedia.org/wiki/Big_Dig_ceiling_collapse was because they used the wrong glue (epoxy, but basically the same thing).

[aitchnyu]

My car (Yaris in India, not to be confused with 3-10 other cars across the world with the name) has them in headlights, tail lights, under mirror and 5 large lumps on roof. Not at an angle though. I would have expected the science to be ubiquitous and all planes to have them first.

[m3kw9]

Why not on commercial aircraft?

[CrimsonCape]

The concept of laminar flow applied to aircraft seems like a little-explored topic. Clearly there is benefit as the article demonstrates.

Imagine these small "microvanes" evolved into 3D printed laminar-flow structures.

For example, think a honeycomb pattern extruded into hundreds of small tubes. Or, as another example, aircraft with "fur"...imagine the leading edge of a wing covered in fine stiff bristles. Literally "combing" the air as it passes over the wing.

[JumpCrisscross]

> laminar flow applied to aircraft seems like a little-explored topic

You’re sort of describing the fundamental gestalt of an aircraft: lift. Aerospace engineers (hello!) spend a lot of time on laminar flow about the wing because when it stops being laminar the flow separates and then the plane goes down more.

[master_crab]

Laminar flow over aircraft has been studied for decades. Hell the mustang used a NACA airfoil specifically designed to maximize laminar flow.

[Onavo]

Is this for laminar flow or is this a vortex generator?