The Archer Fish - a Natural Born Water Warrior

[isoaker]

While there are actually several types of Archer fish, they all share their ability to hunt down insects with jets of water. What I didn't realize is some of the really funky fluid dynamics these fish use to knock down insects. I always thought they simply squirted with enough force, but this article in Wired shows how Archer fish manage to get their streams to accelerate mid-flight. Now THAT's pretty funky... I wonder if this could somehow be incorporated into a water blaster.

[the oncoming storm]

That is already used in water guns but it's imposible to see in real time. Max-D's would have this afecct to a greater degree than others.

(edit) this is probably why the XP 90 shoots further with the pulsator mounted.

[isoaker]

I would agree with the suggestion that the XP90's pulse stream may show this effect since the moving part may squeeze out water faster, but Max-D blasters don't increase stream speed through their shots. If anything, all air-pressure blasters with standard nozzles lose force and speed during their stream creation.

[SSCBen]

Thanks for sharing this article, isoaker.

I recently started looking for ways to control water droplet size because my theoretical analysis suggests that larger droplets have better range. Having an accelerating fluid is one way to do this that I had not considered. Now I have to think about how to implement this to test it. It's amazing how such things develop in nature.

[the oncoming storm]

let me explain,

while the valve is opening adiqite flow rate is not available but water tension still forces the full nozzle to be used to eject (and less flow + same opening + less speed)

[isoaker]

let me explain,

while the valve is opening adiqite flow rate is not available but water tension still forces the full nozzle to be used to eject (and less flow + same opening + less speed)

Spelling aside, the same could be said for a regular air pressure system or even CPS-system.

The stream the Archer fish is generating is a carefully crafted pulse with the latter part of the burst pushed out faster, resulting both in increasing stream speed as the stream continues its flight together with multiplied force due to the droplets merging mid-flight. Max-D systems allow the initial stream to be generated as close to the maximum pressure/force generated by the pressurized air, but as water exits the blaster, pressure within drops, thus stream speed also drops pretty much from the moment the nozzle is opened. There is no significant slower initial stream followed by an increased speed trailing pulse as is described in the article.

That said, for this to work in practice for a water blaster, the distance of the target would also matter since you'd want the initial slower stream and trailing faster stream to meet at the point of contact with the target. Thus, the optimal timing and speed for the varied pulse would depend on how far away the target is. Cool phenomenon, but would be very hard to do when target distances can vary quite a bit between shots.