- Location
- U.S.
Hmm. You raise a good point, and I don't know if this is practical to figure out without some difficult CFD work, but I also think there's a flaw in this analysis.Unless the solid core has incredible viscosity / tensile strength, you'd get toroidal flow around the edges, producing outward jets at ground level. More like sandblasting until it gets a chance to thaw, and probably less total cryogenic-liquid flooding than the original EM nuke, but I'm pretty sure there'd still be some.
Wherever particles of air-ice bounce off the core's surface, make it back out to the edge of the effect, and encounter normal-temperature materials, they'll flash-boil. If the resulting explosion reduces net incoming air flux in that vicinity, thus allowing more bounces to reach the edge, that would mean exhaust jets are self-reinforcing, so it'd be less stable than it seems based on an assumption of negligible turbulence.
I don't think its quite correct to model the material in the AoE as a fluid - at best, its a powder. It's inexorably a supercooled gas that should instantly freeze as soon as it actually touches anything. In fact, after a little searching, it turns out that a air molecule collides with its neighbors more frequently than I was expecting, so even under sonic flow conditions at 50 kelvin you might be dealing with a very finely powdered snow after a few meters.
I think any interaction of inflowing gas will tend to result in combination, not flow - two opposing gas streams will more-or-less stick together into dust with the net momentum of each. This effect will especially interfere with any material that tries to escape near a border - that is the region where the inrushing supercooled gas will be the finest, and so most readily able to frost onto a surface, and the momentum of that stream is pointing directly inwards.