Non newtonian fluids can reorganize their atomic structure if exposed to stress forces.
Would it be a better defense against an explosion than a solid cover?
In: Chemistry
The fluid behaves like a solid. What happens when you set off a bomb in a solid? Bits of solid fly everywhere.
If you watch a non newtonian fluid take impacts on youtube, it’s pretty clear that this is exactly what happens. Instead of yielding like a fluid, it yields like a solid, with cracks forming and everything.
The benefit of non-Newtonian fluids is that you can very easily manipulate them/allow them to flow into place (depending on viscosity) but they can be strong like a solid once needed. They aren’t magically *stronger* than a solid of the same shape.
Non-Newtonian fluids arent magically “stronger” than solids, they just act weird. They still break the same as everything else, they just sometimes act like a solid, and sometimes like a liquid.
Others have explained well why this wouldn’t work but I’d just like to point out there’s active research into [body armor formed by impregnating a Kevlar matrix with non-Newtonian fluid](https://www.researchgate.net/publication/333824103_Bullet_Proof_Vest_using_Non-Newtonian_Fluid).
The advantage is less that there’s some magical property of these fluids that make them absolutely bulletproof, more that it’s flexible enough where you can armor awkward areas where plate armor is impractical (armpits, groin, inside elbows, etc).
The guy who does the hydraulic press have another channel name “Beyond the press” and one of their videos, U8R0txBYayg, is them blowing up a tub of the stuff. The result is chunky for a bit then turns soft. It is like it melts as it flies.
Non-newtonian fluids turn into a solid when under pressure. They do not, however, turn into a strong solid. For exable ooblek basically behaves like moist cornstarch when hit. So no, they would be awful at stopping a bomb.
I’ll start by going for some definitions, then I’ll answer the question.
* Newtonian fluid: a fluid that has a viscosity independent of shear rate.
* Non-newtonian fluid: a fluid that has a viscosity dependent on shear rate.
There are two main types of non-newtonian fluids. Shear thinning and shear thickening. There are other behaviours as well like fluids that have a yield stress, meaning that irrespective of the dependency of the viscosity on shear rate, there is a minimum stress needed to get those to flow (think toothpaste).
Non newtonian fluids also tend to have zero shear and infinite shear plateaus. Basically, there are limits to the dependency of viscosity on shear rate. Here’s a graphical example of what the viscosity would look like for a shear thinning fluid: https://www.researchgate.net/figure/The-Carreau-viscosity-model-and-concept-of-n1_fig1_359466144
Shear thickening is basically just flipping the curve.
Now that, that has been said, it was fairly obvious you meant shear thickening fluids.
If an explosive goes off in a shear thinning fluid, the fluid will obviously behave like a liquid or gas (air is a fluid too, so are other gases) of a viscosity corresponding on the shear generated by the explosive. Basically, will behave like you’d expect water and the like to behave.
As for shear thickening fluids, some will behave for a very short time more like a solid, but will quickly go back to behaving like their original selves. An explosion is a very rapid and violent phenomenon, but it is also very short lived, you would be able to see it using high-speed video, but you’ll miss using regular speed footage or the Mk. I eyeball. Other shear thickening fluids that have a lower upper viscosity limit will still ultimately behave like you would expect a fluid to.
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