Posted by tosh 2 days ago
More specifically, tidal flow obeys Froude similarity, not Reynolds. Matching the model's Froude number to the real Bay's requires enough depth for gravity waves and tides to scale correctly, which the vertical exaggeration provides.
But the distortion makes the flow too efficient, so copper strips are added throughout to achieve the right frictional resistance.
When building scaled models, adjustments have to be made to create that similitude, usually done by comparing some dimensionless number at the real scale and model scale. If you're using water, maybe you can't adjust the viscosity, so you may you have to adjust the velocity to get the same dimensionless number. Everything doesn't just scale linearly; you tweak the variables to achieve the dimensionless value so the whole system dynamics remain faithful.
E.g.,
(you can actually drink it if it's reasonably pure. it's even less toxic than ethanol, but the hangover is terrible)
In other countries the government would be involved but it would be a civilian rather than military role
- flood management is not easy to monetize so there is not much incentive for private industry. The timelines for design decisions (100 year, 500 year) often don’t mate well with private incentives
- it crosses many property boundaries which makes it hard to manage unless you have the rights of a government
- much of the work is still done by private companies but managed by the government, just like other infrastructure works like roads, bridges etc.
When I saw a demo, they had an easter egg of a Loch-Ness type monster in it.
There's also a topographical map of the harbour at St Ives showground but it's purely non-hydrographical. But it's almost disappeared now through neglect.
Meanwhile the Soviets probably found a little inlet somewhere that was "close enough", evicted anyone who lived there and excavated it to match.
Some junior engineer probably had to wake up at 1am to take a kayak out to "Little Kotlin Island" to change the tape in the recording equipment in time for the tide change.