Will a vortex form if you pump water up via the bathtub drain?

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A vortex will not spontaneously form if water is pumped up through a bathtub drain in reverse flow. While a little angular momentum can create a vortex with forward flow, this effect diminishes when water spreads out in the basin. Even if a vortex is initially nudged in one direction, it cannot sustain itself due to dissipation effects. The discussion suggests that time reversal phenomena are unlikely to occur in this context. Overall, the mechanics of water flow dictate that a vortex relies on specific conditions that are not met with reversed flow.
Swamp Thing
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... And if it won't form spontaneously with reversed flow, then will a vortex at least sustain itself once we nudge it in one direction?
 
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No. A little angular momentum becomes a rapidly spinning vortex when the water flows into a relatively narrow drain. If water emerged from the drain into the basin, any angular momentum would be spread across the basin - and thus would spin more slowly.
 
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Swamp Thing said:
Summary:: ( Forward Flow --> vortex ) ==> ( Reversed flow --> vortex ) ??

... And if it won't form spontaneously with reversed flow, then will a vortex at least sustain itself once we nudge it in one direction?
You mean if it could be a time reversal phenomenon.
Dissipation effects can probably rule that out to be completely true.
 
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